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13
MAINTENANCE
 
A. PRELIMINARY INSTRUCTIONS
 
13A1. General. Extreme vigilance and care are necessary in the inspection, cleaning, and repair of parts. Personnel performing repair work should use common sense in judging whether or not a part should be put back into service or discarded. If there is any doubt, the part should be replaced. With the exception of the bearings and electrical equipment, corrosion should be removed from the parts by washing them in kerosene. Hydraulic equipment should be washed in clean fresh water. After cleaning, dry the parts thoroughly, and apply a light film of gyro oil to prevent rusting or corrosion of the parts. Use Navy-approved cleaning fluid to clean grease and oil from the parts. Keep the bearings oiled and clean by wrapping them in wax paper until they are needed for assembly. Clean the contacts and slip rings with ordinary paper to remove any film of oil or grease. Smooth off pitted contacts with a jeweler's file and polish with a burnishing tool. Do not use crocus cloth, crocus paper, or sandpaper on the contacts. Replace all cracked or broken parts. The area in which repair work is being done should be kept clean to prevent dust and dirt from getting on the parts.

13A2. Operating the system on a static head. This is a means of checking the operation of

Figure 13-1. Maneuvering cocks and drain cocks
positioned for operating on static head.
Figure 13-1. Maneuvering cocks and drain cocks positioned for operating on static head.

  the log system while the ship is at rest on the surface. By shutting off the pressure on one side of the bellows, unequal pressure is obtained on the bellows, and the system will operate at one speed in the same manner as if the ship were underway. This permits the checking and inspection of the system under operating conditions. The log is operated on the static head as follows: Turn the valves to the static head operating position as shown in Figure 13-1. The system will now operate at approximately 5 knots. After inspection, turn the valves to their secured position as shown in Figure 11-2. The transmitter indicator mechanism will then stop operating and the speed pointers should be at the zero position.

Figure 13-2. Maneuvering cocks and drain cocks
in zero position.
Figure 13-2. Maneuvering cocks and drain cocks in zero position.

13A3. Checking the operation of the system with a weight and arm. This operation is a means of checking the functioning of the system when the ship is either at rest or underway, on the surface or submerged. It is described in detail in Section 14A10.

13A4. Setting the C-adjustment. (See Figures 13-2 and 13-3.) The C-adjustment mechanism consists of a micrometer assembly which connects the bellows rod with the main balance arm. This micrometer is a means of

 
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Figure 13-3. C-adjustment assembly.
Figure 13-3. C-adjustment assembly.
Figure 13-4. Maneuvering cocks and drain cocks
positioned to check for clogged rodmeter.
Figure 13-4. Maneuvering cocks and drain cocks positioned to check for clogged rodmeter.
 

Figure 13-5. Maneuvering cocks and drain cocks
positioned for blowing out static line.
Figure 13-5. Maneuvering cocks and drain cocks positioned for blowing out static line.

 
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adjusting the master transmitter indicator so that the speed pointer will point at exact zero on the dial. Setting the C-adjustment is accomplished in the following manner: Set the valves to the zero position as shown in Figure 13-2. Thoroughly vent the hydraulic system as described in Section 11A5. If the speed

Figure 13-6. Maneuvering cocks and drain cocks
positioned for blowing out dynamic line.
Figure 13-6. Maneuvering cocks and drain cocks positioned for blowing out dynamic line.

  pointer is not at the zero position on the dial, turn the micrometer thimble (shown in Figure 13-3) until the pointer is at exact zero position on the dial. This adjustment is important because all other log adjustments are performed only after making certain that the C-adjustment is correct.

Figure 13-7. Maneuvering cocks and drain cocks
positioned for blowing out both hydraulic lines.
Figure 13-7. Maneuvering cocks and drain cocks positioned for blowing out both hydraulic lines.

 
B. MAINTENANCE OF RODMETER
 
13B1. Testing for obstruction in the rodmeter. The rodmeter may become clogged with jellyfish, mud, seaweed, or other foreign matter. Consequently the pressure difference will not be normal, and the mechanism will not register correctly. The following test must be performed when the ship is on the surface. Position the valves and vent cocks as shown in Figure 13-4. If a full stream of water does not flow from both drain cocks, it is an indication that the line not flowing is clogged.

13B2. Blowing out the rodmeter. This operation should be performed with the rodmeter in its extended, or operating, position. It is good practice to blow out both lines even if the tests for obstruction indicate that only one line is clogged, as foreign matter has probably entered both passages. Blow out the static line in the following manner: Position the maneuvering cocks and drain cocks as shown in Figure 13-5. Disconnect the dynamic line at the pressure snubber as shown in Figure 13-5 and plug the line openings with

  rubber corks. Apply low-pressure air to the fitting at the drain maneuvering cock. After the static line is blown clear, remove the rubber corks and reconnect the dynamic line. Blow out the dynamic line as follows: Position the maneuvering cocks and drain cocks as shown in Figure 13-6. Apply low-pressure air to the fitting at the drain maneuvering cock. To blow out both the static and dynamic lines simultaneously, position the maneuvering cocks and drain cocks as shown in Figure 13-7. Apply low-pressure air to the fitting at the drain maneuvering cock. After blowing out the hydraulic lines, test for obstructions in the rodmeter as described in Section 13B1. Vent the hydraulic system thoroughly after blowing out the rodmeter as described in Section 11A5.

13B3. Removing solid obstructions from the rodmeter. (See Figure 13-8.) If obstructions cannot be removed by blowing out the rodmeter with compressed air, the following operations are necessary: Raise the rodmeter to its fully housed position. Close the sea

 
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valve. Raise the rodmeter until its lower end is above the sea valve extension. Using a soft brass wire, dig out the obstructions from the openings on the lower end of the rodmeter. Do not use steel wire or a drill to clean out the openings as they may score the openings, or break off in the passages. Blow out the rodmeter as described in Section 13B2; in this case, however, the rodmeter need not be extended into the sea. Have a crew member hold his hand near the rodmeter openings to detect the flow of air which indicates that the opening and tubing are clear. Repeat this operation until all the passages are clear.

Align the lower end of the rodmeter with the opening in the sea valve extension, and carefully lower the rodmeter to its fully housed position. Care should be exercised in lowering the tip of the rodmeter through the packing gland so that the packing will not be pushed out of the gland. At the fully housed position the tip of the rodmeter is approximately 1 inch above the sea valve gate. Open the sea valve. Place the hoist stop bracket in its original position above the rodmeter. It is important that the stop bracket be in position above the rodmeter at all times, except while performing the above operation, or when the rodmeter is being replaced. Lower the rodmeter either to its normally housed position or to its fully extended position. Place the hoist crank in the brackets provided, and replace the deck plate over the sea valve.

  Figure 13-8. Rodmeter and hoist.
Figure 13-8. Rodmeter and hoist.
 
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C. REPLACING DAMAGED RODMETER
 
13C1. General instructions. If the rodmeter is bent so that it cannot be drawn up into the ship, it will be necessary to install a spare rodmeter. Do not attempt to force the damaged rodmeter up into the ship, as the hoist mechanism may be damaged. The removal and installation operations should be carried out only when the ship is surfaced. If the damaged rodmeter is to be salvaged, it may be accomplished if a diver is available. Lower the diver over the side of the ship so that he can rig a line around the damaged rodmeter. Secure the opposite end of the line to the ship

Figure 13-9. Bendix rodmeter.
Figure 13-9. Bendix rodmeter.

  so that the rodmeter may be pulled out of the water after it is pushed out of the sea valve.

13C2. Breaking out the spare rodmeter. Break out the spare rodmeter and place it alongside of the hoist mechanism so that it will be immediately available when needed.

13C3. Removing the strap and handle assembly. (See Figure 13-9.) Loosen the hose clamps and remove the two lengths of hose from the nipples on the upper end of the rodmeter. Remove the nipples from the rodmeter and plug the tapped openings with wooden plugs or standard 1/8-inch pipe plugs. Disconnect the hoist chain link from the rodmeter. Remove the two nuts and bolts that secure the straps and handle to the rodmeter and remove the straps and handle. Raise the hoist chain until the connecting link is in its topmost position against the stop bracket above the rodmeter (Figure 13-8).

13C4. Installing the spare rodmeter. (See Figure 13-9.) The spare rodmeter is equipped with straps and handle. If the damaged rodmeter is partially raised, push it downward until the dowel pins rest on top of the packing gland on the sea valve extension. Remove the two pipe plugs from the spare rodmeter and install the hose fittings. Connect the hose to the spare rodmeter and tighten the hose clamps securely. Place the tip of the spare rodmeter on top of the damaged rodmeter. Drive out the dowel pins from the damaged rodmeter. Push downward on the spare rodmeter until it is completely free of the ship. Connect the link on the chain hoist to the rodmeter handle. Vent the hydraulic system in accordance with the instructions given in Section 11A5.

 
D. MAINTENANCE OF PRESSURE BELLOWS
 
13D1. General. The submarine bellows are matched as to spring-rate at the factory and should not be disassembled. The three sections of the bellows assembly (Figure 13-10) should be replaced as a unit.

13D2. Removing the bellows chamber. (See Figure 13-11.) Remove the master transmitter

  indicator cover retaining screws and cover. With the rodmeter in its housed position, turn the valves and maneuvering cocks to the drain position (Figure 11-6). Spread the ends of the scissors spring to disengage the spring from the micrometer and pivot, and remove the scissors spring. Remove the snap rings from
 
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Figure 13-10. Cutaway of bellows assembly.
Figure 13-10. Cutaway of bellows assembly.
 
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Figure 13-11. Bellows installation on master
transmitter case.
1. SPRING ARM GUIDE
2. MAIN BALANCE ARM PIVOT
3. MICROMETER PIVOT
4. MICROMETER CENTER SCREW
5. LOCK NUT
6. UPPER BEARING HOUSING
7. COUNTERWEIGHT BRACKET
8. BELLOWS ASSEMBLY
9. ROTATING COUNTERWEIGHT
10. SNAP RING
11. COUNTERWEIGHT SHAFT
12. MICROMETER THIMBLE
13. MICROMETER BARREL
14. SCISSORS SPRING ASSEMBLY
Figure 13-11. Bellows installation on master transmitter case.

each end of the counterweight shaft, and remove the shaft. Lift out the counterweight and its bracket. Do not disturb, in any way, the counterweight mounted on the bottom of the main balance arm. Carefully block or hold the bellows chamber in place while removing the nuts from the bellows mounting studs. Carefully lower the bellows assembly from the master transmitter case.

13D3. Removing the bellows from the chamber. (See Figures 13-12, 13-13, and 13-14.) Unscrew and remove the bellows chamber cap. The cap spacer and caution plate are removed with the chamber cap. Loosen the setscrew in the compensating spring holder and unscrew (counterclockwise) and remove the spring holder. Carefully remove the compensating spring assembly from the compensating spring bushing. The spring bushing is removed

  after the drain screw is removed. Remove the drain screw and gasket from the lower end of the drain tube. Loosen the three setscrews on the compensating spring bushing and remove the bushing from the drain tube. Using the special bellows wrench, which is stowed in the spare parts box, hold the lower end of the bellows as shown in Figure 13-13. Unscrew and remove the lock nut that secures the lower end of the bellows assembly to the bellows chamber. Unscrew the unions that secure the maneuvering cocks assembly to the bellows chamber and place the assembly to one side. Unscrew and remove the C-adjustment mechanism from the bellows rod by holding the rod with a wrench and unscrewing the micrometer center screw from the rod. The counterweight bearing is removed with the C-adjustment assembly. Remove the lock nut that secures the upper end of the bellows assembly to the chamber cover in the same manner that the bellows lower lock nut was removed. Loosen the three setscrews that secure the main counterweight support in position on the upper end of the bellows assembly and unscrew and remove the main counterweight support from the bellows. Remove the chamber cover by removing the eight cap screws and lock washers that secure the cover to the chamber. Lift the bellows assembly out of the bellows chamber. The bellows may be stuck in the chamber. If it is, the application of low-pressure air to the dynamic opening in the chamber will facilitate its removal.

13D4. Installing the bellows assembly in the chamber. (See Figures 13-12, 13-13, and 1314.) Make certain that the bellows chamber gasket is installed on the upper end of the chamber. Carefully insert the bellows into the chamber. Secure the lower end of the bellows to the chamber with the lock nut as follows

Tighten the lock nut in position by holding the lower end of the bellows with the special spanner wrench as shown in Figure 13-13, while turning up the nut. Place the bellows chamber cover gaskets in position on the chamber cover. Carefully place the chamber cover over the threaded end of the bellows so as not to burr the threads. Align the two large pipeline openings in the cover and in the

 
139

Figure, 13-12. Bellows assembly removed.
Figure, 13-12. Bellows assembly removed.
 
140

Figure 13-13. Removing bellows lower lock nut.
Figure 13-13. Removing bellows lower lock nut.

chamber so that the large openings are on the same side of the chamber. Align the mounting holes and install the eight cover retaining screws and lock washers. Install the lock nut that secures the upper end of the bellows to the chamber cover. Temporarily install the main counterweight bracket and bearing assembly on the upper end of the bellows assembly.

Do not tighten the setscrews in the counterweight bracket and bearing assembly at this time, as a final adjustment of the positioning of the assembly must be made when the bellows assembly is installed on the master transmitter indicator case.

Place the upper bearing housing assembly on top of the bellows rod with the large flange end of the bearing housing toward the top of the bellows rod. Temporarily install the C-adjustment mechanism in the top of the bellows rod by turning the micrometer center screw into the rod. Do not tighten the lock nut on the micrometer center screw or position the micrometer thimble at this time, as a final adjustment must be made when the complete bellows assembly is installed on the bottom of the master transmitter indicator case.

13D5. Installing the bellows assembly on the master transmitter case. (See Figure 13-11.) Position the micrometer thimble of the C-adjustment mechanism in its approximate

  central position on the micrometer barrel. This is done so that the thimble can be moved in either direction when making the final zero adjustment. Make certain that the bellows stud gaskets are in good condition and are installed on the studs. Lift the bellows assembly into position on the bottom of the transmitter case. Hold the bellows assembly in this position while adjusting the micrometer screw in the top of the bellows rod so that the pivot on top of the micrometer will just clear the pivot recess in the main balance arm pivot when the rubber stud gaskets are compressed. Tighten the lock nuts on the bellows mounting studs so that the rubber stud gaskets are completely compressed and a metal-to-metal contact is obtained between the bellows chamber cover and the transmitter case. Secure the micrometer center screw in position by tightening the lock nut on the center screw up against the inner race of the counterweight bearing. Install the scissors spring assembly to hold the micrometer up against the main balance arm pivot. Apply a coating of white lead compound to the threads of the maneuvering and drain cocks. Install the two unions connecting the maneuvering cocks with the two large tapped openings, one in the chamber cover and one in the bellows chamber. Tighten the connections. Install the two drain cocks, one in the cover and the other in the chamber. Tighten the connections. Install the drain tubing in the drain cocks. Place the rotating counterweight in position on the counterweight support, and install the counterweight shaft and the two snap rings that secure the weight to the support. There should be approximately 1/32-inch clearance between the arms of the counterweight and the counterweight bearing. Check the clearance of the counterweight to see that it does not touch the case, the weight on the main balance arm, or any stud. Position the counterweight for proper clearance by screwing the counterweight support upward or downward as necessary. When the proper clearance is obtained, secure the counterweight support in position by tightening the setscrews provided in the support. The setscrew should not be made extremely tight, as the threads on the upper end of the
 
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1. C ADJUSTMENT ASSEMBLY
2. UPPER BEARING HOUSING ASSEMBLY.
3. COUNTERWEIGHT SHAFT.
4. COUNTERWEIGHT BRACKET AND BEARING ASSEMBLY.
5. SNAP RING.
6. COUNTERWEIGHT AND BRACKET ASSEMBLY.
7. RUBBER GASKET.
8. STUD NUT.
9. LOCK WASHER.
10. STUD GASKET.
11. UPPER BELLOWS LOCKNUT.
12. CHAMBER COVER STUD.
13. CAP SCREW.
14. LOCK WASHER.
15. CHAMBER COVER.
16. THREE-WAY STATIC MANEUVERING COCK.
17. OUTER UNION.
18. INNER UNION.
19. COUPLING NUT.
20. STATIC DRAIN COCK.
21. NEOPRENE CHAMBER COVER GASKET.
22. BELLOWS ROD.
23. UPPER BELLOWS GASKET.
24. BELLOWS ASSEMBLY.
25. LOWER BELLOWS GASKET.
26. VELLUMOID GASKET.
27. DYNAMIC DRAIN COCK.
28. BELLOWS CHAMBER.
29. PIPE NIPPLE.
30. FOUR-WAY DYNAMIC MANEUVERING COCK.
31. OUTER UNION.
32. INNER UNION.
33. COUPLING NUT.
34. PIPE NIPPLE
35. THREE-WAY MANEUVERING DRAIN COCK.
36. COUPLING.
37. BELLOWS CHAMBER DRAIN PLUG.
38. CAUTION NAMEPLATE.
39. CAP SPACER.
40. LOWER BELLOWS LOCK NUT.
41. COMPENSATING SPRING BUSHING.
42. GASKET.
43. SCREW.
44. COMPENSATING SPRING.
45. COMPENSATING SPRING NOSE.
46. COMPENSATING SPRING HOLDER.
47. CHAMBER CAP.
  Figure 13-14. Bellows assembly, disassembled.
 
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belows assembly will be damaged. There are three setscrews provided in the main counterweight support. It is necessary to tighten only the most accessible setscrew. Fill the hydraulic system with water. (See Section 11A8.) Vent the system thoroughly. (See Section 11A5.) Energize the system by turning   on the switches in the control room. Make the C-adjustment by turning the micrometer thimble upward or downward until the pointer reads zero on the speed dial. (See Section 13A4.) Check the system for dive error. (See Section 13E2.)
 
E. COMPENSATION OF SUBMARINE BELLOWS FOR DIVE ERROR
 
13E1 General. The submarine bellows is carefully adjusted for dive error when the bellows assembly is made at the factory. This adjustment should not be tampered with   d. The submarine dives to approximately 300 feet. If the log still reads zero knots, there is no diving error and the system can be put into operation without further
Figure 13-15. Dive error compensating mechanism.
Figure 13-15. Dive error compensating mechanism.
unless the bellows has been damaged, and the replacement of the bellows assembly becomes necessary. 13E2. Checking the system for dive error. The following operations are necessary in checking the system for dive error:

a. The system is completely filled with water and bled of air.

b. The valves and vent cocks are set to the zero position.

c. The C-adjustment of the master transmitter indicator is set so that the speed pointer reads zero knots.

  Figure 13-16. Maneuvering cocks and drain cocks
positioned for dive error adjustment.
NOTE: Open slowly Leave open until pressure is dissipated. Zero point with "C" adjustment, then close drain cock as shown.
Figure 13-16. Maneuvering cocks and drain cocks positioned for dive error adjustment.
 
143

adjustment. However, there usually is a positive error.

13E3. Adjusting for dive error. (See Figures 13-15 and 13-16.) When there is a positive dive error noted after performing the-operations outlined in Section 13E2, the following adjustment procedure is necessary:

a. Remove the chamber cap from the bottom of the bellows housing.

b. Loosen the setscrew on the compensating spring holder and screw up (clockwise) on the compensating spring holder, thus compressing the compensating spring. This will increase the error of the pointer indicator. The spring should be compressed until the indicated error of the pointer is about twice the original error.

c. Remove the static pressure in the following manner: Position the valves and vent the cocks as shown in Figure 13-16. Partially open the static drain cock as shown by the dotted outline in Figure 13-16. The static drain cock must be opened slowly so as to remove the pressure gradually. This is important as the sudden opening of the drain cock will damage the bellows. After the pressure has been dissipated, the speed pointer will drop but will not return to its zero position.

d. Set the speed pointer to the zero position by means of the C-adjustments. See Section 13A4.)

e. Position the valves and vent cocks to the zero position by turning the static maneuvering cock to the horizontal position as shown by the dotted lines in Figure 13-16. The above procedure may have to be repeated several times by alternately operating the static maneuvering cock and the static drain cock until the correct spring pressure balances out the diving error. Then tighten the setscrew in the compensating spring holder.

f. Install the cap on the lower end of the bellows assembly. For an example of the method used in adjusting for dive error, refer to Section 13E4.

13E4. Example of adjusting for dire error. (See Figure 13-15 and 13-16.) With the maneuvering cocks in zero position, and the

  pointer indicating zero knots, the submarine dives to 300 feet. If the pointer slowly rises and stops at 1 knot, the adjustment is made in the following manner:

a. Remove the chamber cap from the bottom of the bellows housing.

b. Loosen the setscrew securing the compensating spring holder.

c. Turn the screw holder clockwise (up), compressing the compensating spring until the log indicates 2 knots.

d. The static maneuvering cock (Figure 13-16) is closed and the static drain cock (Figure 13-16) is slowly and only partially opened. This reduces the pressure within the bellows chamber to the ship's atmosphere, and the pointer drops to 1.3 knots.

e. By means of the C-adjustment, the pointer is made to indicate zero knots.

f. The static drain cock is again closed, and the static maneuvering cock slowly opened. This increases the pressure within the bellows chamber to the water pressure of the sea. The pointer now rises to 0.6 knots.

g. The compensating spring is again compressed until the log indicates 1.2 knots.

h. The static maneuvering cock is closed and the static drain cock is slowly opened as before. The pointer drops to 0.7 knots. The pointer is made to read zero by means of the C-adjustment.

i. The static drain cock is again closed and the static maneuvering cock opened to the sea. The pointer rises to only 0.2 knots. If the cycle is repeated once more, the diving error, for all practical purposes, will have been eliminated.

j. If the log indications should become negative for increasing pressures, then the compensating spring is adjusted too tightly, and must be backed off.

k. After the spring holder has been set in the proper position, the setscrews are tightened, thus locking the spring holder against the dynamic bellows cap. Do not damage the threads by forcing the setscrews too tightly.

l. Replace the bellows chamber cap, being

 
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sure to insert the caution plate and cap spacer between the cap and the bellows chamber.

13E5. Alternate method of adjusting for dive error. If a pressure pump is available, the bellows can be compensated when the ship is in port. The pump is connected to the

  static maneuvering cock. The maneuvering cocks are set in the zero position. The pressure should be checked by means of a pressure gage. A pressure of 150 pounds should be alternately applied and removed, while the adjustments described in Section 13E4 are being made.
 
F. MAINTENANCE OF SPEED AND DISTANCE INDICATOR
 
13F1. Removing the pointer and dial. (Figures 13-17, 13-18, and 13-19.) Remove the case cover retaining screws and cover. Remove the three screws and lock washers that secure the unit to the case, and lift the unit from the case. Remove the three screws and   lock washers that secure the pointer hub cover and the pointer to the pointer hub, and remove the pointer. Remove the three screws and lock washers that secure the dial assembly to mounting studs, and carefully lift the dial assembly off the studs. The deflector
Figure 13-17. Speed and distance indicator removed from case.
Figure 13-17. Speed and distance indicator removed from case.
 
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Figure 13-18. Rear view of speed and distance indicator.
Figure 13-18. Rear view of speed and distance indicator.
assembly, ringlight sectors, and lamp sockets are removed with the dial.

13F2. Installing the dial and pointer. (See Figures 13-19 and 13-17.) Place the dial assembly in position on the dial mounting studs, and secure it with the three screws and lock washers provided. Place the pointer and pointer hub cover in position on the pointer hub, and secure with the three screws and lock washers provided. The pointer may be positioned in reference to the zero mark on the dial by loosening the pointer retaining screws and shifting the pointer to the desired

  location. Place the instrument in the case and secure with the three screws and lock washers provided. Place the case cover in position on the case and install the cover retaining screws.

13F3. Removing the deflector assembly. (See Figures 13-17 and 13-19.) Remove the cover from the case. Remove the four flathead machine screws that secure the deflector assembly to the ringlight sectors, and remove the deflector assembly.

13F4. Installing the deflector assembly. (See Figures 13-17 and 13-19.) Carefully

 
146

place the deflector assembly in position on the ringlight sectors, and secure with the four flathead machine screws provided. Install the case cover.

13F5. Replacing burned-out lamps. (See Figure 13-19.) Remove the deflector assembly. (See Section 13F3.) Replace the burned out lamps with new lamps. Install the deflector assembly. (See Section 13F4.)

13F6. Removing the ringlight sectors. (See Figure 13-19.) Remove the dial assembly from

  13F4.) Install the dial assembly. (See Section 13F2.)

13F8. Removing the lamp sockets. (See Figure 13-19.) Remove the dial assembly. (See Section 13FL) Remove the lamps from the sockets. From the front of the dial remove the two screws that secure the lamp socket to the back of the dial. Remove the terminal screw from the ground wire. Push the center contact wire forward, unsolder the wire from the center contact, and remove the wires from

Figure 13-19. Speed and distance indicator, dial removed.
Figure 13-19. Speed and distance indicator, dial removed.
the dial mounting studs. (See Section 13F1.) Remove the deflector assembly. (See Section 13F3.) From the rear side of the dial remove the eight screws (two to each sector) that secure the sectors to the dial, and remove the sectors.

13F7. Installing the ringlight sectors. (See Figure 13-19.) Place one of the ringlight sectors in position on the back of the dial and secure with the two screws provided. The other sectors are installed in the same manner. Install the deflector assembly. (See Section

  the socket. Remove the two screws that secure the lamp plate to the lamp bracket, and pull the socket out of the lamp block. The other three lamp sockets are removed in the same manner.

13F9. Installing the lamp sockets. (See Figure 13-19.) Place the socket in the lamp block. Position the lamp plate and secure it with the two screws provided. Push the lead wire into the rear end of the socket and solder this wire to the center contact. Connect the ground wire to the lamp plate. Place

 
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the lamp socket in position and install the two screws that secure the socket to the dial. Install the lamp in the socket. The other three sockets are installed in the same manner. Install the dial assembly. (See Section 13F2.)

13F10. Removing the tap switch. (See Figure 13-19.) Remove the case cover. Remove the unit from the case. Remove the two screws that secure the tap switch bracket to the mounting plate, and carefully pull the tap switch forward to make the wire connections accessible. Unsolder and tag the wires for ready identification. Remove the nut and toothed lock washer that secure the tap switch to the tap switch bracket.

13F11. Installing the tap switch. (See Figure 13-19.) Place the new tap switch in position in the tap switch bracket, and secure with the nut and toothed lock washer provided. Solder the wires to the terminals on the tap switch. Place the tap switch assembly in position on the mounting plate and secure it with the two screws provided. Install the unit in the case. Install the case cover.

13F12. Removing the distance counter. (See Figure 13-19.) Remove the dial assembly. (See Section 13F1.) Remove the four screws and lock washers that secure the counter to the front of the main mounting plate, and remove the counter. The worm gear is

Figure 13-20. Transformer wiring diagram.
Figure 13-20. Transformer wiring diagram.

  removed with the counter assembly. The worm gear is removed from the countershaft by loosening the setscrew, knocking out the tapered pin, and pulling the worm gear off the countershaft.

13F13. Installing the distance counter. (See Figure 13-19.) Place the worm gear on the countershaft and secure it with the setscrew and tapered pin. Place the counter in position on the front of the mounting plate with the worm gear and worm properly meshed, and secure with the four screws provided. Install the dial assembly. (See Section 13F2.)

13F14. Removing the transformer. (See Figure 13-18.) Remove the dial assembly. (See Section 13F1.) From the front of the mounting plate remove the two screws that secure the transformer, to the mounting plate. Unsolder the primary leads from the jack connection. Unsolder the secondary leads from the tap switch. Tag the tap switch terminals for ready identification.

13F15. Testing the transformer. (See Figure 13-20.) Connect the two primary leads to the 115-volt a.c. line. Connect a voltmeter across the secondary leads as shown in Figure 13-20. Voltage readings should be taken as shown in Figure 13-20.

13F16. Installing the transformer. (See Figure 13-18.) Place the transformer in position on the back of the mounting plate, and secure it with the two screws provided, from the front of the mounting plate. Solder the two primary leads to the terminals on the jack connection. Solder the secondary leads to the terminals on the tap switch. Install the dial and pointer. (See Section 13F2.)

13F17. Removing the self-synchronous distance repeater. (See Figures 13-21 and 13-22.) Remove the unit from its case. Remove the terminal screws and washers that secure the lead wires to the distance repeater. Tag the wires for ready identification. The terminals are marked S1, S2, S3, R1, and R2. Remove the three screws and lock washers that secure the distance repeater motor mounting clamps to the motor mounting plate, and remove the repeater from the mounting plate.

 
148

Figure 13-21. Self-synchronous distance repeater removed.
Figure 13-21. Self-synchronous distance repeater removed.
 
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Figure 13-22. End view of distance repeater.
Figure 13-22. End view of distance repeater.

13F18. Disassembly of the distance repeater. (See Figure 13-23.) Remove the three screws that secure the terminal cover to the terminal ring assembly, and remove the terminal cover. Unsolder the stator leads from

  the terminal plates on the terminal ring assembly. Remove the three screws that secure the terminal ring assembly to the stator housing, and remove the ring assembly. The end and side contact assemblies are secured in the terminal ring assembly with one screw. Slide the insulating plate off the wires. Remove the tapered pin from the front end of the rotor shaft. This pin engages the slot on the shaft extension of the worm shaft. Remove the three screws that secure the end cap assembly to the stator housing, and remove the end cap assembly. Pull the rotor and damper assembly from the stator housing. Remove the ball bearing and bearing spring from the front end of the rotor shaft. Using a small drive punch, drive out the outer race and shims from the end cap assembly. Holes are provided in the end cap assembly for the insertion of a drive punch. Remove the shim and bearing outer race from the back end of the stator housing in the same manner. Remove the bearing and brass dust guard from the rear end of the rotor shaft.

13F19. Assembly of the self-synchronous distance repeater. (See Figure 13-23.) Place the shim and bearing outer race in the back

Figure 13-23. Distance repeater partially disassembled.
1. END CAP SCREW
2. END CAP
3. SHIMS
4. FRONT BEARING
5. ROTOR AND DAMPER, ASSEMBLY
6. REAR BEARING
7. STATOR HOUSING
8. STATOR LEADS
9. TERMINAL RING, ASSEMBLY
10. TERMINAL COVER
11. TERMINAL COVER SCREW
12. TERMINAL RING SCREW
13. INSULATING PLATE
14. REAR BEARING OUT RACE
15. DUST GUARD
16. BEARING SPRING
17. FRONT BEARING OUTER RACE
Figure 13-23. Distance repeater partially disassembled.
 
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end of the stator housing, with the flange end of the race toward the end of the stator housing. Place the brass dust guard on the rear end of the rotor shaft, with the shoulder on the dust guard facing toward the end of the shaft. Place the ball bearing over the end of the rotor shaft and against the shoulder on the brass dust guard. Carefully insert the rotor and damper assembly into the stator housing, being careful to align the bearing in the outer race in the back end of the stator housing. Place the bearing spring over the front end of the rotor shaft, with the large diameter of the spring adjacent to the damper flywheel. Place the ball bearing over the front end of the rotor shaft and adjacent to the bearing spring. Place the shims and bearing outer race in the end cap assembly. Install the end cap assembly over the front end of the rotor shaft, and up against the stator housing. Secure the end cap with the three screws provided. Place the insulating plate over the stator leads, with the smooth side of the plate adjacent to the stator housing. Place the terminal ring assembly over the stator leads and up against the stator housing. Secure the ring with the three screws provided. Solder the stator leads to the terminals on the terminal plates. Install the terminal cover on the terminal ring with the three screws. If a new rotor assembly has been installed, it will be necessary to drill a pin hole in the front end of the rotor shaft. Using the old rotor shaft as a guide, measure the distance from the center of the pin hole to the end of the rotor shaft in the same manner as shown for the speed repeater in Figure 13-26. Drill a transverse hole using a No. 55 drill for a 5/16-inch X 0.052 inch stainless steel pin. Press the pin into the hole in the rotor shaft. It is not necessary to set the distance repeater to electrical zero.

13F20. Installing. The self-synchronous distance repeater. (See Figure 13-21.) Connect the stator and rotor lead wires to the terminal ring of the distance repeater. Tighten the terminal screws securely. Align the pin on the front end of the rotor shaft with the slot provided in the worm shaft extension, and place the distance repeater in position on the

  mounting plate. Secure the repeater with the three clamps and the three clamp screws provided. Install the unit in the case.

13F21. Removal of the self-synchronous speed repeater. (See Figure 13-18.) Remove the interior unit from the case. Remove the terminal block cover retaining screws and cover. The terminal block outer cover plate is removed with the terminal block cover. Cut the string that secures the lead wires together in order to fan out the lead wires near the terminals. Make a note of the position of the end contact terminal. This is the R1 lead terminal. Progressing in a counterclockwise direction, the other two brush terminals are identified as the R2 terminal and the R3 brush terminal. The wires are tagged with metal tags. The stator lead S2 is connected to the upper stator terminal, and the stator lead S1 is connected to the lower stator terminal. Remove the terminal screws that secure the leads to the terminal block, and

Figure 13-24. Terminal block assembly
partially disassembled.
1. CONTACT PLATE
2. TAPPED SIDE CONTACT CLAMP PLATE
3. SIDE CONTACT SPRING
4. SIDE CONTACT CLAMP PLATE
5. LOCK WASHER
6. SIDE CONTACT SCREW
7. CONTACT TENSION SPRING
8. CONTACT SPRING BRACKET
9. END CONTACT CLAMP PLATE
10. TERMINAL BLOCK
11. TERMINAL PLATE
12. END CONTACT SPRING
13. END CONTACT SCREW
Figure 13-24. Terminal block assembly partially disassembled.

 
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remove the leads from the terminals. Cut off the terminal lugs from the ends of the rotor leads in order that these wires can be pulled out of the holes provided in the terminal block. Remove the three clamp screws and clamps that secure the speed repeater to the mounting plate, and remove the speed repeater.

13F22. Removing the contact assembly. The contact assembly can be removed from the speed repeater as a unit. Remove the terminal block cover retaining screw and the terminal block cover. Disconnect the rotor and stator lead wires from the terminal block as described in Section 13F21. Remove the two screws and lock washers that secure the terminal block to the rear end cap. Cut off the terminal lugs from the two stator leads that connect the stator with the contact plates. This is necessary in order that these two wires may be pulled through the holes provided in the terminal block. Remove the terminal block from the rear end cap.

13F23. Removing the contacts. (See Figure 13-24.) Support the front end of the speed repeater on wooden blocks so that the terminal block is in an upright position. Remove the end contact assembly in the following manner: Remove the two screws and lock washers that secure the contact clamp plate, contact spring, and contact spring bracket to the contact plate. Remove the parts from the terminal block with tweezers. Remove the side contact assemblies in the following manner: Remove the two screws and lock washers that secure the side contact clamp plates and the side contact spring to the contact plate, and carefully remove the parts with tweezers. The second side contact assembly is removed in the same manner.

13F24. Cleaning the contacts and slip ring. Clean the contacts and the slip ring with a clean piece of note paper. Smooth the pitted contacts with a jeweler's file, and polish the surfaces with a burnishing tool. Do not; use emery cloth or crocus paper as fine particles from the cloth or paper will become imbedded in the soft metal of the contacts and slip ring.

  13F25. Installing the contacts. (See Figure 13-24.) Install one of the side contact assemblies in the following manner: Using tweezers, align one contact spring and the two contact clamp plates with the contact plate. Install the two screws and lock washers that secure the spring and clamp plates to the contact plate. The second side contact spring is installed in the same manner. Install the end contact assembly as follows: Align the contact spring bracket, contact spring, and contact clamp plate with the end spring contact plate, and install the two screws and lock washers that secure the end spring contact in position on the contact plate.

13F26. Installing the contact assembly. (See Figure 13-25.) Insert the two stator wires through the holes provided in the terminal block. These are the two holes nearest the outer circumference of the terminal block. Be careful not to bend the contact springs. Secure the terminal block to the rear end cap with the two screws provided. Solder the terminal lugs on the ends of the two leads from the stator, and connect these wires to the contact plate with the screws and lock washers provided. Connect the S1 lead to the lower stator terminal, and the S2 lead to the upper stator terminal. Insert the R1 lead through the lower hole provided in the terminal block, the R2 lead through the upper hole, and the R3 lead through the center hole. Solder the terminal lugs on the ends of these rotor leads. Connect these rotor leads to the contact plates. Place the terminal block outer cover plate in position on the terminal block, and install the terminal block cover on the terminal block. Secure the cover with one screw. Install the unit in its case.

13F27. Removing the speed repeater rotor and bearings. (See Figure 13-25.) Remove the self-synchronous speed repeater. (See Section 13F21.) Remove the terminal block. (See Section 13F22.) Lift off the terminal block center cover plate and the terminal block inner cover plate. The two terminal lead insulating bushings are removed with the terminal block inner cover plate. Scribe a locating mark on the rear end cap and on the

 
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Figure 13-25. Speed repeater partially disassembled.
1. END CAP SCREW
2. LOCK WASHER
3. FRONT END CAP
4. SHIMS
5. BEARING SPRING
6. BEARING OUTER RACE
7. FRONT BEARING
8. BEARING INNER RACE
9. DUST GUARD
10. ROTOR AND DAMPER ASSEMBLY
11. STATOR SHELL
12. STATOR LEADS
13. REAR BEARING
14. REAR END CAP
15. INSULATING BUSHING
16. TERMINAL BLOCK INNER COVER PLATE
17. TERMINAL BLOCK CENTER COVER PLATE
18. TERMINAL BLOCK ASSEMBLY
19. TERMINAL BLOCK SCREW
20. TERMINAL BLOCK OUTER COVER PLATE
21. TERMINAL BLOCK COVER

Figure 13-25. Speed repeater partially disassembled.
adjacent stator shell so that the end cap can be installed in the same relative position at assembly. Remove the three rear end cap retaining screws and lock washers, and remove the rear end cap. The rear bearing outer race and shim are removed with the rear end cap. Remove the setscrew that secures the pointer hub to the rotor shaft, and remove the pointer hub. Remove the three front end cap retaining screws and lock washers, and remove the front end cap. Be careful not to lose the bearing outer race, bearing spring, and shim from the front end cap. Remove the rotor and damper assembly from the stator shell. Remove the bearing, bearing inner race, and dust guard from the front end of the rotor shaft. Remove the rear bearing, bearing inner race, and dust guard from the rear end of the rotor shaft. Remove the front bearing outer race, bearing spring, and shims from the front end cap. Remove the rear bearing outer race and shim from the rear end cap. The outer race and shim are removed from the rear end cap by inserting a small drive punch through holes in the rear end cap and driving out the shim and outer race.   13F28. Assembling the self-synchronous speed repeater. (See Figure 13-25.) Place the rear bearing dust guard on the rear end of the rotor shaft, with the shoulder on the guard facing away from the rotor. Place the bearing inner race on the rear end of the rotor shaft adjacent to the dust guard. Place the shim and outer bearing race in the rear end cap with the flange of the race toward the cap. The race is a light press fit into the end cap. Place the rear ball bearing on the rear bearing inner race. Install the rear end cap on the stator shell with the locating scribed marks aligned. Secure the rear end cap with the three screws and lock washers provided. Carefully install the rotor and damper assembly into the stator shell, making certain that the rear end of the stator shaft is aligned with the opening in the rear end cover. Support the rear end cover and stator shell on wooden blocks in order to assemble the front end of the repeater. Place the front bearing dust guard over the front end of the rotor shaft, with the shoulder of the guard away from the rotor. Install the front bearing inner race adjacent to the front bearing dust guard. Place the ball bearing on the inner
 
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race on the front end of the rotor shaft. Install the shims, bearing spring, and outer race in the opening provided in the front end cap. The lugs of the bearing spring should face the rotor, and the flange of the outer race should face the end cap. Install the front end cap on the stator shell, being careful when inserting the rotor shaft through the end cap not to damage the bearing. Secure the front end cap with the three screws and lock washers provided. Turn the rotor shaft by hand to make sure that the rotor rotates freely. Turn the repeater over so that the front end cap rests on wooden blocks on the bench. Place the two lead insulating bushings over the stator leads, with the flange end of the bushings away from the end cap. Insert the bushings into holes provided in the rear end cap. Install the terminal block inner cover plate on the rear end cap by inserting the stator leads through the large holes in the inner cover. Place the terminal block center cover plate over the slip rings and against the rear end cap. Install the terminal block. (See Section 13F26.)

13F29. Installing the self-synchronous speed repeater. (See Figures 13-18, 13-25, and 13-26.) Align the scribe mark on the front end cap with the scribe line on the back of the mounting plate, and place the repeater in position on the back of the mounting plate. Secure in position with the three clamps and clamp screws provided. If a new rotor has been

Figure 13-26. Locating position of pointer hub
handle screw.
Figure 13-26. Locating position of pointer hub handle screw.

  installed it will be necessary to drill a new pointer hub screw hole in the new shaft. Locate and drill the hole in the following manner: Measure the distance of the centerline of the hole from the front end of the old rotor shaft as shown in Figure 13-26. Mark the location of the hole and drill a hole in the new shaft, using a No. 32 drill. Tap a bole for a 6-40 screw. Install the pointer hub on the shaft and secure with the screw provided. Install the dial and pointer. (See Section 13F2.) Set the speed repeater to electrical zero. (See Section 13F30.)

13F30. Setting the speed repeater to electrical zero. (See Figure 13-27.) Set the speed

Figure 13-27. Wiring diagram showing connections
for setting speed repeater to electrical zero. (Caution: Do not leave power on for more than 5 minutes or motor will overheat)
Figure 13-27. Wiring diagram showing connections for setting speed repeater to electrical zero.

repeater to electrical zero as follows: Contact the terminals of the speed repeater S1 to R2 to one side of the line. Connect S2 to R1 and R3 to the other side of the line as shown in Figure 13-27. Energize the unit. Do not leave the power on for mote than 5 minutes, or the motor will overheat. When the unit is energized, the shaft will assume a definite position (zero position). Loosen the three screws that secure the pointer to the pointer hub, and shift the pointer to the zero position on the dial. Lock the pointer in this position by tightening the three pointer screws.

13F31. Disassembly of the counter drive worm assembly. (See Figure 13-28.) Remove the distance counter. (See Section 13F12.) Remove the two screws that secure the worm bracket to the mounting plate. Carefully pry the worm bracket from the mounting plate. The bracket is pinned to the mounting plate, and care should be exercised not to bend the

 
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Figure 13-28. Counter drive worm assembly disassembled.
Figure 13-28. Counter drive worm assembly disassembled.
pins. Drive out the tapered pin that secures the worm on the shaft. Pull the worm assembly out of the worm bracket. Remove the outer bearing, dust washer, worm, inner dust washer, and inner bearing from the worm shaft. It may be necessary to file off the burrs from the pin holes in order to remove the inner bearing.

13F32. Assembly of the counter drive worm assembly. (See Figure 13-28.) Place the inner bearing on the worm shaft, with the bearing shield toward the shaft extension. Install the inner dust washer on the shaft, with the

  shoulder on the washer facing the inner race of the inner bearing. Place the worm on the shaft and install the tapered pin that secures the worm on the shaft. Install the outer dust washer on the shaft, with the shoulder on the washer facing the front end of the shaft. Place the worm and shaft assembly in the worm bracket. Align the dowel pin holes of the bracket with the holes provided in the mounting plate, and install the bracket on the mounting plate. Secure the bracket to the mounting plate with the two screws provided. Install the counter. (See Section 13F13.)
 
G. MAINTENANCE OF MASTER TRANSMITTER INDICATOR
 
13G1. Removing the unit from the case. (See Figure 13-29.) Lower the bellows from the case so that the C-adjustment mechanism will clear the bottom of the main balance arm. (See Section 13D2.) Remove the screws that secure the main mounting plate to the case, and carefully lift the master transmitter log mechanism from its case. Place the log mechanism on a bench, or in an inspection stand.

13G2. Replacing the pointer and dial. (See Figure 13-29.) Remove the screw that secures the pointer and pointer washer to the pointer hub, and carefully lift the pointer off the pin of the pointer hub. Mark the back of the pointer so that it may be installed in the same relative position. Remove the three screws that secure the dial to the dial posts, and remove the dial. Place the new dial in position on the dial studs and secure with the three screws provided. Place the pointer and pointer washer in position on the pointer hub

  and secure with the pointer screw provided.

13G3. Removing the follow-up motor. (See Figure 13-30.) Remove the four screws that secure the follow-up motor mounting clamp to the main mounting plate, and lift the motor to one side so that the lead wires are made accessible. Unsolder the wires from the motor terminals, and mark the wires for ready identification. Place the motor to one side.

13G4. Replacing the follow-up motor. (See Figures 13-31 and 13-32.) Remove the fan from the follow-up motor shaft by loosening the setscrew in the fan hub. Remove the motor mounting clamp from the old motor by removing the two screws, lock washers, and spacer washers that secure the clamp to the motor. Remove the gear assembly from the old motor by removing the snap ring and lifting the gear assembly from the gear mounting stud of the motor as shown in Figure 13-31. Place the gear assembly on the stud of

 
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Figure 13-29. Master transmitter indicator removed from case.
1. POINTER
2. DIAL
3. FOLLOW-UP MOTOR
4. 500-OHM RHEOSTAT
5. DISTANCE TRANSMITTER
6. DIFFERENTIAL ASSEMBLY
7. FOLLOWER
8. ROTATING DISK
9. COMPONENT FRAME ASSEMBLY
10. MAIN MOUNTING PLATE
11. CONTACT ARM
12. CONTACT ASSEMBLY

Figure 13-29. Master transmitter indicator removed from case.
the new motor and secure it with the snap ring as shown in Figure 13-32. Place the spacer washers in position on the new motor, and place the motor mounting bracket on the spacer washers. Secure the bracket to the motor with the two screws and lock washers

provided. Place the fan on the motor shaft, and tighten the setscrews in the fan hub.

13G5. Installing the follow-up motor. (See Figure 13-30.) Solder the motor lead wires to the terminals on the motor. Place the motor and mounting bracket in position on

 
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Figure 13-30. Removing follow-up motor.
Figure 13-30. Removing follow-up motor.
 
Figure 13-31. Replacing follow-up motor, Step 1.
Figure 13-31. Replacing follow-up motor, Step 1.
 
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Figure 13-32. Replacing follow-up motor, Step 2.
Figure 13-32. Replacing follow-up motor, Step 2.
 
Figure 13-33. Rear view of master transmitter indicator.
Figure 13-33. Rear view of master transmitter indicator.
 
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the front of the main mounting plate, and secure it with the four screws provided.

13G6. Removing the self-synchronous speed transmitter. (See Figure 13-33.) Remove the master transmitter indicator mechanism from the case. Remove the terminal block cover retaining screw and the terminal block cover. The terminal block outer cover plate is removed with the terminal block cover. Disconnect the stator and rotor leads in the same manner as described for the disconnection of the leads of the speed repeater. (See Section 13F21.) Unsolder and remove the rotor lead terminal lugs. Pull the wires out of the terminal block. Turn the power motor shaft by hand so that the gear on the motor speed transmitter shaft will clear the main cam. Remove the three clamp screws and clamps that secure the speed transmitter to the main mounting plate, and carefully remove the speed transmitter.

13G7. Disassembly of the speed transmitter. (See Figure 13-34.) Remove the gear from

  the front end of the rotor shaft by removing the handle screw and socket head setscrew that secure the gear to the shaft. Remove the front end cap retaining screws, and the front end cap. Carefully pull the rotor assembly out of the stator shell. Remove the front end bearing, bearing inner race, and front bearing dust guard from the front end of the rotor shaft. Remove the outer race and shims from the front end cap. Unsolder the terminal lugs from the stator inner leads. Remove the terminal block retaining screws and lock washers, and remove the terminal block. Remove the terminal block inner and center cover plates from the rotor shaft. Remove the terminal lead insulating bushings from the rear end cap. Remove the rear end cap retaining screws and lock washers, and remove the rear end cap from the stator shell. Remove the rear ball bearing, ball bearing inner race, and rear bearing dust guard from the rear end of the rotor shaft. Knock the rear bearing outer race and shims out of the rear end cap.
Figure 13-34. Self-synchronous speed transmitter partially disassembled.
1. SETSCREW.
2. HANDLE SCREW.
3. SPEED TRANSMITTER DRIVEN GEAR.
4. FRONT END CAP SCREW.
5. FRONT END CAP.
6. SHIMS.
7. BEARING OUTER RACE.
8. FRONT BEARING.
9. BEARING INNER RACE.
10. DUST GUARD.
11. ROTOR ASSEMBLY.
12. STATOR SHELL.
13. STATOR LEADS.
14. DUST GUARD.
15. BEARING INNER RACE.
16. REAR BEARING.
17. BEARING OUTER RACE.
18. SHIMS.
19. REAR END CAP.
20. INSULATING BUSHING.
21. TERMINAL BLOCK INNER COVER PLATE.
22. TERMINAL BLOCK CENTER COVER PLATE.
23. LOCK WASHER.
24. REAR END CAP SCREW.
25. COVER RETAINING SCREW.
26. TERMINAL BLOCK.
27. LOCK WASHER.
28. TERMINAL BLOCK SCREW.
29. TERMINAL BLOCK OUTER COVER PLATE
30. TERMINAL BLOCK COVER.

Figure 13-34. Self-synchronous speed transmitter partially disassembled.
 
159

13G8. Assembly of the speed transmitter. (See Figure 13-34.) Place the shims and bearing outer race in the rear end cap, with the flange on the race toward the end cap. Install the rear end cap on the stator shell by inserting the stator leads through the end cap, and secure the end cap to the stator shell with the four screws provided. Place the rear bearing dust guard on the rear end of the rotor shaft with the shoulder of the guard toward the end of the shaft. Install the rear bearing inner race and rear bearing on the rotor shaft. Place the rotor assembly into the stator shell, being careful not to damage the bearing as the shaft is inserted through the rear end cap. Place the shims and front bearing outer race in the front end cap, with the flange of the race toward the end cap. Install the front bearing dust guard on the shaft, with the shoulder of the guard facing the end of the shaft. Install the bearing inner race and the front bearing on the rotor shaft. Install the front end cap on the stator shell and secure with the four screws and lock washers provided. Turn the rotor shaft to make sure that the shaft is rotating freely. Install the gear on the front end of the shaft, and secure it with the handle screw and socket head setscrew. If a new rotor has been installed, it will be necessary to drill and tap a hole in the shaft for the gear screw. (See Section 13G9.) Place the lead insulating bushings over the stator leads, and insert the small end of the bushings into the holes provided in the rear end cap. Place the terminal block center and inner cover plates on the rear end cap, with the stator leads inserted through the holes provided in the inner cover plate. Hold the terminal block in position near the rear end cap, and insert the stator leads through the two holes provided nearest the outer circumference of the terminal block. Carefully spread the side contacts while installing the terminal block so that the contact springs will not be bent. Secure the terminal block to the rear end cap with the two screws and lock washers provided. Solder the terminal lugs on the end of the stator inner leads, and connect the inner lead terminals to the terminal plate located between the stator leads.   Place the speed transmitter in position on the main mounting plate, and temporarily install the clamps and clamp screws. Do not tighten the clamp screws at this time, as the motor will have to be shifted when setting it to electrical zero. Connect the rotor and stator leads to the terminal block in the same manner as described in Section 13F26. Set the speed transmitter to electrical zero. (See Section 13G10.)

13G9. Drill and tap rotor shaft. When a new rotor is installed in the self-synchronous speed transmitter, it is necessary to drill and tap a hole in the shaft for installation of the motor-driven gear. This operation is performed in the following manner: Locate the position of this hole by measuring the distance from the end of the shaft to the centerline of the hole on the old rotor shaft as shown in Figure 13-26. Locate the position of the hole on the new rotor shaft. Using a No. 29 drill, drill a hole through the shaft. Tap this hole for an 8-36 screw. Place the gear on the rotor shaft and secure it with a handle screw and socket head setscrew. Set the speed transmitter to electrical zero. (See Section 13G10.)

13G10. Setting the speed transmitter to electrical zero. Install the dial and pointer. (See Section 13G2.) The speed pointer should be set at zero on the dial. While the speed transmitter is temporarily installed on the main mounting plate, move the transmitter back so that the gear on the shaft is disengaged from the gear on the cam and bracket assembly. Use one of the speed and distance indicators (repeaters) as a checking instrument. Energize the system. Manually turn the speed transmitter gear until the pointer on the speed and distance repeater is indicating zero. Carefully push the speed transmitter forward until the gears are properly meshed. Any slight shifting of the speed and distance repeater pointer is compensated for by a slight rotation of the speed transmitter stator shell in the main mounting plate. When the pointer is at exact electrical zero, tighten the motor mounting clamps. Place the terminal block outer cover plate in position on the terminal block, and install the terminal block

 
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cover. Secure the cover with the screw provided. Install the unit in the case.

13G11. Distance transmitter. The self-synchronous distance transmitter of the master transmitter indicator is removed, disassembled, and assembled in the same manner as the speed transmitter. (See Sections 13G6, 13G7, and 13G8.) It is not necessary to set the distance transmitter to electrical zero.

  remove it from the differential shaft. The left-hand friction disk is removed with the friction disk holder. Remove the clutch plate, right-hand friction disk, and spring holder plate from the differential shaft. Drive out the pin that secures the slipping clutch compression spring in the spring adjuster, and remove the spring from the shaft. Loosen the spring adjuster socket head setscrew, and remove the spring adjuster. Loosen the
Figure 13-35. Differential assembly removed.
Figure 13-35. Differential assembly removed.
13G12. Removing the differential assembly. (See Figure 13-35.) Drive out the pin that secures the universal center in the universal joint. Move the universal center to the right and out of the universal joint. Remove the four screws that secure the differential frame to the main mounting plate. Carefully remove the differential assembly from the main mounting plate. The differential frame is pinned to the mounting plate and must be carefully pried away from it. The differential assembly is usually replaced as a unit. In the event that it become necessary to clean and replace individual parts, the differential assembly must be disassembled, as described in Section 13G13.

13G13. Disassembling the differential assembly. (See Figure 13-36.) Loosen the friction disk holder socket head setscrew and

  bearing collar setscrew, and remove the bearing collar. Loosen the distance transmitter drive gear setscrew, and remove the gear from the shaft. Remove the bearing from the distance transmitter drive gear. Remove the dust washer from the left-hand side of the differential frame. Remove the nut, lock washer, dust washer, and spider bevel gear from the spider shaft. Remove the bearing from the spider bevel gear.

Loosen the two socket head setscrews in the differential frame. Push the differential shaft toward the left, and remove the bearing and bearing spacer from the left side of the differential frame. Loosen the setscrew in the differential right-hand gear; then pull the shaft toward the left in order to remove the bearing from the right-hand gear. Drive out the tapered pin from the differential

 
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Figure 13-36. Differential assembly disassembled. Note: Parts identified by black dot and white figures are all assembled within the frame
1 FRICTION DISK HOLDER.
2 LEFT HAND FRICTION DISK.
3 CLUTCH PLATE.
4 RIGHT HAND FRICTION DISK.
5 SPRING HOLDER PLATE.
6 COMPRESSION SPRING PIN.
7 SLIPPING CLUTCH COMPRESSION SPRING.
8 SPRING ADJUSTER.
9 BEARING COLLAR.
10 DRIVE GEAR BEARING.
11 DISTANCE TRANSMITTER DRIVE GEAR.
12 DUST WASHER.
13 BEARING.
14 LEFT HAND BEARING SPACER.
15 HOLLOW SHAFT.
16 BEARING.
17 DUST WASHER.
18 LEFT HAND DIFFERENTIAL GEAR.
19 DIFFERENTIAL SHAFT AND SPIDER.
20 SPIDER BEVEL GEAR.
21 BEARING.
22 DUST WASHER.
23 LOCK WASHER.
24 NUT.
25 DIFFERENTIAL FRAME.
26 DUST WASHER.
27 BEARING.
28 TAPERED PIN.
29 RIGHT HAND DIFFERENTIAL GEAR.
30 DUST WASHER.
31 BEARING.
32 BEARING INNER SPACER.
33 BEARING OUTER SPACER.
34 BEARING.
35 DUST WASHER.
36 UNIVERSAL JOINT.

Figure 13-36. Differential assembly disassembled.
right-hand gear, and remove this gear and the dust washer from the universal joint. Pull the universal joint assembly from the right side of the differential frame; then remove the bearing, bearing inner and outer spacers, second bearing, and dust washer from the universal joint. Loosen the differential left-hand bevel gear setscrew, and remove the gear from the hollow shaft. Push the hollow shaft assembly out of the left side of the differential frame. Remove the dust guard and bearing from the hollow shaft. Remove the differential right-hand bevel gear bearing and dust washer from the right end of the differential shaft. Remove the differential shaft and spider from the differential frame.

13G14. Assembly of the differential assembly. (See Figure 13-36.) Install the bearing and dust washer, with the shoulder facing the bearing race, on one end of the differential

  hollow shaft. Install the bearing spacer, second bearing, and dust washer on the opposite end of the hollow shaft in the same manner. Place the left-hand differential gear on the long end of the differential shaft, with the gear teeth facing the spider; then insert the long end of the shaft through the left-hand side of the differential frame, from right to left. Slide the hollow shaft assembly over the long end of shaft and into approximate position in the left-hand side of the differential frame.

Make certain that the long section of the hollow shaft is facing the spider, otherwise the hollow shaft assembly will not line up properly in the frame.

Install the dust washer on the left-hand side of the universal joint, with the shoulder on the dust washer facing away from the large section of the universal joint. Install the inner and outer bearing spacers; then

 
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install the universal joint left-hand bearing adjacent to the inner and outer spacers. Install the bearing in the left-hand differential gear. Hold the left-hand differential gear in position on the differential frame, and insert the universal joint assembly into the opening in the right side of the frame and into the left-hand differential gear. Place the dust washer on the short end of the differential shaft, with the shoulder of the washer away from the spider. Push the differential assembly toward the right while holding the universal joint assembly in position, to engage the differential shaft and universal joint. Install the bearing in the spider bevel gear; and place this gear in position on the spider, with the gear teeth meshing with the differential gears. Install the dust washer on the spider bevel gear, with shoulder of the washer toward the bearing race. Install the lock washer and nut that secure spider bevel gear in position on the spider.

Align the hole in the right-hand differential gear with the hole in the universal joint and install the tapered pin that secures the gear in position on the joint. Tighten the socket head setscrew in this gear hub. Install the bearing in the distance transmitter drive gear and install this gear on the left end of the hollow shaft, with the gear teeth facing away from the frame; then tighten the setscrew in the gear hub. Align the gears and shaft assembly in the differential frame and tighten the two socket head setscrews that secure the bearing spacers in the differential frame. Tighten the setscrew in the left-hand differential gear hub. Manually turn the spider and shaft by hand to be sure that the parts are rotating freely.

Install the dust washer adjacent to the distance transmitter drive gear with the shoulder of the washer facing the bearing. Install the bearing collar on the left end of the shaft, and tighten the collar setscrew. Place the spring adjuster adjacent to the bearing collar, and tighten the adjuster setscrew. Install the slipping clutch compression spring in the spring adjuster. Compress the spring and install the pin that secures the spring in

  the adjuster. Install the spring holder plate, with the slot in the plate aligned over the spring holder pin.

Install the right-hand friction disk, with the slot in the disk over the spring holder pin. Install the clutch plate, left-hand friction disk, and friction disk holder on the differential shaft, with the flat on shaft aligned with the setscrew in the friction disk holder hub; then tighten the hub setscrew.

13G15. Installing the differential assembly. (See Figure 13-35.) Place the differential assembly in approximate position on the main mounting plate so that the universal center is inserted within the universal joint. Use care in aligning the clutch plate with the rheostat assembly. Align the pin holes in the main mounting plate with the pins in the universal frame, and carefully place the universal assembly in exact position on the mounting plate. Install the four screws that secure the differential frame to the mounting plate. Install the pin that secures the universal center in the universal joint.

13G16. Removing the constant speed motor. (See Figure 13-37.) Remove the log mechanism from its case. Remove the differential assembly so that the motor mounting screws are accessible. (See Section 13612.) Loosen the two setscrews that secure the rotating disk to the motor shaft. Disconnect and tag the electrical leads. Remove the two screws and lock washers that secure the limit switch assembly to the mounting plate, and swing the switch assembly out of the way. From the front of the main mounting plate remove the four screws and lock washers that secure the constant speed motor to the mounting plate. One man holds the disk while a second man carefully pulls the motor shaft out of the friction disk. The motor shaft is sometimes burred because the setscrews have been forced too tightly. In such a case the motor will have to be turned clockwise and counterclockwise through approximately a 45-degree arc while pulling it away from the disk. Remove the friction disk. Cut the string that secures the lead wires to the main leads. Remove the tape from the ends of the leads,

 
163

Figure 13-37. Constant speed motor removed.
Figure 13-37. Constant speed motor removed.
and unsolder the lead connections. Tag the leads for ready identification. Place the motor to one side.

13G17. Disassembly of the constant speed motor. (See Figure 13-38.) Remove the three reduction gear housing screws, and remove the housing. Remove the four screws that secure the motor to the condenser, and lift the motor to one side of the condenser so that the end caps may be removed. Remove the four screws that secure the back end cap to the motor frame, and remove the end cap. Pull the rotor assembly from the motor frame. Remove the bearing from the worm gear end

  of the rotor shaft. The bearing is a light press fit. Remove the bearing and shims from the back end cap.

13G18. Assembly of the constant speed motor. (See Figure 13-38.) If the felt retainers have been removed for any reason place a felt washer between the two felt retainers, and place the retainers in position or the back end cap. Secure the retainers with the four screws provided. Place the bearing on the worm end of the rotor shaft, with the bearing shield toward the shaft end. Place the shims and bearing in the back end cap with the bearing shield toward the end, cap

 
164

Figure 13-38. Constant speed motor partially disassembled.
Figure 13-38. Constant speed motor partially disassembled.
Place the reduction gear housing in position on the front end of the motor, and secure with the three screws provided. Carefully insert the rotor into the frame with the worm on the shaft meshed with the gear on the reduction gear housing. Place the back end cap in position on the motor frame, being careful when aligning the rear end of the rotor shaft with the bearing in the back end cap. Secure the end cap with the four screws provided. Place the constant speed motor in position on the rear of the main mounting plate, and secure it with the four screws and lock washers provided. Place the rotating disk on the motor shaft and secure it with the two setscrews provided. Place the limit   switch assembly in position on the main mounting plate and secure it with the two screws and lock washers provided. Connect the electrical leads. Install the differential assembly. (See Section 13G15.)

13G19. Disassembly of the reduction gear housing. (See Figures 13-38 and 13-39.) Remove the reduction gear housing from the motor. (See Section 13G17.) Unscrew and remove the packing nut and three felt washers from the gear housing. Loosen the two setscrews that secure the worm gear on the motor shaft, and pull the drive shaft out of the gear housing. Lift out the worm gear and spacing bushing from the gear housing.

 
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Figure 13-39. Reduction gear housing disassembled.
Figure 13-39. Reduction gear housing disassembled.
Unscrew and remove the lock nut from the adjusting screw. Unscrew and remove the adjusting screw, washer, black felt washer, and thrust disk from the gear housing.

13G20. Assembly of the reduction gear housing. (See Figures 13-38 and 13-39.) Insert the drive shaft into the packing gland in the reduction gear housing. Place the spacing bushing and worm gear on the shaft. Align the holes in the gear hub with the holes in the shaft, and install and tighten the two setscrews that secure the worm gear to the shaft. Install the thrust disk, adjusting screw, black felt washer, plain washer, adjusting screw, and adjusting screw lock nut on the opposite end of the gear housing. Place the three felt washers over the long end of the drive shaft, and slide the washers into the packing gland. Install the packing nut. Install the reduction gear housing on the motor. (See Section 13G18.)

13G21. Removing the power motor. (See Figure 13-40.) Tag the electrical leads to the motor for ready identification. Unsolder the leads from the motor terminal lugs. Remove the four screws that secure the motor to the rear side of the mounting plate, and remove the motor.

  13G22. Disassembly of the power motor. (See Figure 13-41.) Knock out the pin and loosen the setscrews that secure the power motor gear on the power motor shaft, and remove the gear. Remove the four end cap screws and lock washers, and remove the end cap. Knock out the bearing and shim from the end cap. Knock-out holes are provided in the end cap for this purpose. Remove the rotor assembly from the motor housing. The bearing on the opposite end of the rotor shaft will be removed with the rotor. Remove the dust guard from the lower end of the rotor shaft. Remove the bearing and dust guard from the opposite end of rotor shaft. Be careful not to lose the shims that are mounted behind the bearings in the end caps.

13G23. Assembly of the power motor. (See Figure 13-41.) Place the shim in the front end of the motor housing. Place the dust washer and bearing on the upper end of the rotor shaft, with the shoulder of the dust washer facing the bearing. Insert the rotor assembly into the motor housing. Install the dust washer and bearing on the lower end of the rotor shaft in the same manner as described above. Place the shim in the end cap. Place the end cap over the lower end

 
166

Figure 13-40. Removing power motor.
Figure 13-40. Removing power motor.
of the rotor shaft, and in position on the motor housing. Secure the end cap with the four screws and lock washers provided. Align the power motor gear on the end of the rotor shaft, and install the pin through the gear and shaft. Tighten the setscrew that secures the gear to the shaft.

13G24. Installing the power motor. (See Figure 13-39.) Place the power motor in position on the mounting plate, using care when

  meshing the gears. Secure the motor to the mounting plate with the four screws provided. Solder the electrical leads to the terminals on the motor.

13G25. Removing the power motor drive gear assembly. (See Figure 13-42.) Remove the four screws and lock washers that secure the gear assembly to the back end of the mounting plate, and remove the gear assembly. There may be shims mounted between the gear box

 
167

Figure 13-41. Power motor partially disassembled.
Figure 13-41. Power motor partially disassembled.
and mounting plate. Shims are to be installed in the same position at assembly.

13G26. Disassembly of the power motor drive gear assembly. (See Figure 13-43.) Remove the nut and washer from the driven gear end of the worm shaft. Drive out the tapered pin and loosen the setscrew securing the driven gear on the worm shaft; then remove the gear. Remove the dust washer, bearing, and shim from the driven gear end of the worm shaft. Remove the nut and lock washer, dust washer, and bearing from the lower end of the worm shaft. Pull the worm shaft toward the top of the gear box; then tilt the worm shaft upward and remove it from the gear box. Remove the nut and lock washer from the driving gear end of the worm shaft. Knock out the pin, and loosen the setscrew that secures the driving gear on the worm gear shaft, and remove the driving gear. Remove the dust washer, and bearing from the driving gear end of the worm shaft. Remove the nut and

  lock washer from the worm gear end of the shaft. Knock out the pin, and loosen the setscrew that secures the worm gear to the worm gear shaft. Drive the worm gear shaft out of the worm gear. Knock out the bearing outer races from the gear box.

Figure 13-42. Power motor drive gear assembly removed.
Figure 13-42. Power motor drive gear assembly removed.

 
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13G27. Assembly of the power motor drive gear assembly. (See Figure 13-43.) Install a bearing outer race in each of the two recesses in the sides of the gear box. Hold the worm gear in position within the gear box, with the gear hub toward the convex side of the gear box; then insert the worm gear shaft from right to left through the bearing recesses in the gear box, and through the worm gear hub. The long end of the worm gear shaft is toward the left side of the gear box. Align the hole in the shaft and worm gear hub, and install the tapered pin. Tighten the hub setscrew. Install the shims, bearing, dust washer, lock washer and nut on the worm gear end of the   worm gear shaft. Install the shims, bearing, dust washer, and driving gear on the driving gear end of the worm gear shaft. Align the hole in the shaft and in the driving gear hub, and install the tapered pin. Install the lock washer and nut on the driving gear end of the shaft. Install the bearing outer race in the recess in the top of the gear box. Insert the long end of the worm shaft through the lower side of the upper section of the gear box. Move the shaft upward until the lower end of the shaft clears the lower section of the gear box, then insert the lower end of this shaft into the lower section of the gear box. Place the shims, bearing, dust washer, and
Figure 13-43. Power motor drive gear assembly disassembled.
1. NUT
2. LOCK WASHER
3. DRIVEN GEAR
4. TAPERED PIN
5. DUST WASHER
6. BEARING
7. SHIMS
8. BEARING OUTER RACE
9. GEAR BOX
10. WORM GEAR SHAFT
11. BEARING
12. TRANSMISSION SHAFT DRIVE GEAR
13. WORM SHAFT
14. WORM GEAR
Figure 13-43. Power motor drive gear assembly disassembled.
 
169

driven gear on the upper end of the worm shaft. Align the hole in the shaft and in the driving gear hub, and install the tapered pin. Tighten the driven gear hub setscrew. Install the lock washer and nut on the driven gear end of the worm shaft. Install the shims, bearing, dust washer, lock washer, and nut on the lower end of the worm shaft. Turn the gears and shafts by hand to be sure that the parts operate freely.

13G28. Installing the power motor drive gear assembly. (See Figure 13-42.) Align the shims, if used previously, between the gear box, and the main mounting plate, and secure the gear box to the mounting plate with the four screws and lock washers provided.

Figure 13-44. Condenser and resistor assembly
removed.
Figure 13-44. Condenser and resistor assembly removed.

13G29. Removing the condenser. (See Figure 13-44.) Remove the unit from the case. Unsolder and tag the leads at the condenser. Remove the two screws, nuts, and lock washers that secure the condenser to the mounting bracket, and remove the condenser. The other condenser is removed in the same manner.

13G30. Installing the condenser. (See Figure 13-44.) Place the condenser in position on the mounting bracket, and secure it with the two screws, lock washers, and nuts provided. Solder the leads to the condenser. Install the unit in the case.

  13G31. Removing the 250-ohm resistor. (See Figure 13-44.) Remove the unit from case. Unsolder and tag the leads. Remove one elastic stop nut and flat washer from one end of the resistor shaft, and pull the resistor from the shaft.

13G32. Installing the 250-ohm resistor. (See Figure 13-44.) lace the resistor in position on the resistor shaft in the mounting bracket, and install the flat washer and elastic stop nut securing the resistor to the bracket. Solder the leads to the resistor. Install the unit in its case.

13G33. Replacing the 750-ohm resistor. (See Figure 13-44.) Remove the unit from its case. Unsolder and tag the leads. Remove the elastic stop nut and fiber spacer from the resistor stud, and remove the resistor. The other 750-ohm resistor is removed in the same manner. Place the resistor on the resistor stud, and secure it with a fiber spacer and elastic stop nut. Solder the lead to the terminal. Install the unit in its case.

13G34. Removing the condenser and resistor assembly as a unit. (See Figure 13-44.) Remove the unit from the case. Unsolder and tag the ten leads. Remove the three screws that secure the condenser and resistor mounting bracket to the back of the main mounting plate, and remove the condenser and resistor assembly.

13G35. Installing the condenser and resistor assembly as a unit. (See Figure 13-44.) Place the condenser and resistor mounting bracket in position on the mounting plate, and secure with the three screws. Solder the leads to the condensers and resistors.

13G36. Removing the follower assembly. (See Figure 13-45.) Remove the cover from the case. Remove the four screws and lock washers that secure the follower assembly to the main mounting plate, and carefully remove the follower assembly. The follower frame is pinned to the mounting plate, and must be removed carefully so as not to bend the pins.

13G37. Disassembling the follower. (See Figure 13-45.) Disassemble the follower as

 
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Figure 13-45. Follower assembly removed.
1. UNIVERSAL CENTER
2. UNIVERSAL JOINT
3. FOLLOWER
4. FOLLOWER WASHER
5. PIN
6. BEARING CLAMP
7. LEAD SCREW
8. BEVEL GEAR
9. FOLLOWER HUB
10. FOLLOWER TENSION SPRING
11. FOLLOWER SLIDE ROD
Figure 13-45. Follower assembly removed.

follows: Drive out the tapered pin from the follower hub. Remove the nut and lock washer from the right end of the universal joint. Remove the three screws that secure the bearing clamp to the right side of the follower frame, and remove the bearing clamp. Pull the universal joint out of the left side of the follower frame. Lift the follower assembly out of the frame. The inner bearing clamp is removed with the follower. Remove the three screws that secure the follower washer, follower, and follower hub together, and remove the follower. Remove the follower bearings as follows: Remove the outer dust washer, bearing, and inner dust washer from the right side of the follower frame. Remove the outer dust washer, bearing, inner dust washer, and shim from the left side of the frame.

13G38. Assembly of the follower. (See Figure 13-45.) Assemble the follower, follower hub, and follower washer, and secure them with the three screws provided. Place the dust washer, and bearing on the universal

  joint, and partially insert the universal joint through the left side of the follower frame, being sure to align the bearing in the frame recess. Place the dust washer and shim adjacent to the ball bearing on the universal joint. Hold the follower and inner bearing clamp in position within the follower frame, and insert the universal joint through the follower and inner bearing clamp. Install the inner dust washer, bearing, and outer dust washer over the end of the universal joint and into position in the recess in the right side of the follower frame. Place the outer bearing clamp in position on the right side of the follower frame. Align the holes in the inner and outer bearing clamps and install the three screws that secure the clamps to the follower frame. Install the lock washer and nut on the end of the universal joint. Align the hole in the follower hub and hole in the universal joint, and install the tapered pin.

13G39. Removing the follower lead screw. (See Figure 13-46.) Remove the follower assembly from the mounting plate. (See Section 13G36.) Remove the tapered pin, loosen the setscrew that secures the bevel gear on the lead screw, and remove the bevel gear. Remove the four bearing clamp retaining screws, and the right bearing clamp. Remove the right bearing and bearing outer race. Remove the left bearing clamp, bearing, and outer race in the same manner. Unscrew and remove the follower lead screw from the follower slide frame.

13G40. Installing the follower lead screw. (See Figure 13-46.) Screw the follower lead screw into the follower slide frame. Move the follower slide frame clear of one bearing recess, and install the bearing outer race with the race flange facing outward; install the bearing and bearing clamp. Repeat this operation on the opposite end of the lead screw. Place the bevel gear on the right end of the follower lead screw. Align the hole in the gear with the hole in the lead screw, and install the tapered pin. Tighten the setscrew in the gear hub. Place the follower assembly in position on the main mounting plate and secure it with the four screws and lock washers provided.

 
171

Figure 13-46. Follower lend screw removed.
1. BEARING CLAMP
2. FILLISTER-HEAD SCREW
3. BEARING OUTER RACE
4. BEARING
5. BEARING INNER RACE
6. FOLLOWER LEAD SCREW
7. FOLLOWER SLIDE FRAME
8. UNIVERSAL CENTER
9. UNIVERSAL JOINT
10. FOLLOWER TENSION SPRING
11. FOLLOWER SLIDE ROD
12. COUNTER COMPONENT FRAME
13. SETSCREW
14. BEVEL GEAR
15. TAPERED PIN

Figure 13-46. Follower lend screw removed.
13G41. Removing the follower slide rod. (See Figure 13-45.) Remove the follower assembly from the mounting plate. (See Section 13G36.) Remove the follower tension spring by removing the nut, tension screw, spring, and spring cap. Knock out the tapered pin that secures the slide rod in the follower slide frame, and pull out the slide rod.   13G42. Installing the follower slide rod. (See Figure 13-45.) Place the slide rod in position in the follower slide frame, and install the tapered pin that secures the rod in the frame. Install the spring cap, tension spring, tension screw, and tension screw nut. Place the follower assembly on the mounting plate, and secure it with the four screws and lock washers provided.
Figure 13-47. Follower, differential, and rheostat assemblies installed.
1. CLUTCH SPRING ADJUSTER
2. SLIPPING CLUTCH
3. DAMPER HUB
4. RHEOSTAT
5. DISTANCE TRANSMITTER DRIVEN GEAR
6. DIFFERENTIAL SPIDER
7. UNIVERSAL CENTER
8. FOLLOWER TENSION SPRING
9. ROTATING DISK
10. FOLLOWER
11. FOLLOWER LEAD SCREW BEVEL GEAR
12. COMPONENT FRAME UPPER BEVEL GEAR

Figure 13-47. Follower, differential, and rheostat assemblies installed.
 
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13G43. Preparing the follower assembly for adjustment. (See Figure 13-47.) Prepare the follower assembly for adjustment after disassembly in the following manner: Adjust the follower tension spring so that there is a slight tension between the follower and the rotating disk. Unmesh the bevel gears by supporting the gear shaft of the component frame assembly and knocking out the tapered pin from the component frame upper bevel gear hub. Loosen the setscrew in the gear hub, and drop this gear from mesh with the follower lead screw gear. Remove the pin from the universal center so that the disk will rotate independently of the differential assembly.

13G44. Method of adjusting the follower to the center of the rotating disk. (See Figure 13-47.) Disengage the bevel gear on the component frame assembly from the lead screw bevel gear in the following manner: Manually move the main balance arm until the setscrew and tapered pin in the gear hub are accessible; then slip a piece of paper under the contact arm to maintain the position of the tapered pin and setscrew. Loosen the setscrew and drive out the tapered pin, and unmesh the gears. Be sure to support the shaft when driving out the tapered pin in order to prevent bending of the shaft. Move the lead screw gear until the follower runs in one direction; then turn the lead screw gear in the opposite direction until the follower just starts to run in the opposite direction. Manually move the lead screw first one way and then the opposite way until the follower will not rotate in either direction. This is an indication that the follower is in the center position of the rotating disk.

After positioning the follower in the center of the disk, carefully mesh the two beveled gears so that the lead screw gear is not moved from its position. Install the tapered pin and tighten the setscrew in the component frame upper gear. Connect the universal center by installing the pin in the universal joint and universal center. Energize the system, including at least one of the speed and distance indicators. Manually move the main balance arm to the right to raise the

  speed pointer to exactly 5 knots. Place a piece of paper between the contact arm and contacts so that a speed indication of exactly .5 knots is maintained. Measure the time required for the distance counter to register exactly V, mile on the speed and distance indicator. The time should be 6 minutes, plus or minus 3 seconds. If the error is greater than 10 seconds, it is an indication that the slipping clutch is not operating properly, or that the follower is off center position considerably. Test the slipping clutch for proper operation as described in Section 13G45. Adjust the follower to the center of the rotating disk as described above.

13G45. Testing and adjusting the slipping clutch. (See Figure 13-47.) Place a finger on the distance transmitter driven gear and slow down the transmitter. The rheostat brush arm should rotate in a counterclockwise direction. Removing the finger from the transmitter driven gear should cause the rheostat brush arm to rotate to its original position. If the differential spider is turning and the slipping clutch is slipping, indicated by the rheostat brush arm not turning, tighten the clutch spring adjuster in the following manner: Loosen the setscrew in the clutch spring adjuster and move the spring adjuster to the left to tighten the adjustment on the slipping clutch. Repeat the operation until the rheostat brush arm turns with the differential spider.

13G46. Adjusting the rheostat spring tension. (See Figure 13-47.) Another possible cause of a slipping clutch is that the spring in the rheostat is too tight. This causes the rheostat brush arm to stop turning when the differential spider is turning while the finger is slowing down the action of the transmitter driven gear. Adjust the rheostat spring tension as follows: Loosen the setscrew in the damper hub while holding the rheostat brush arm with the other hand. It is necessary to hold the left end of the rheostat shaft, while loosening the setscrew to prevent the spring from ejecting parts from within the rheostat. Carefully move the rheostat shaft assembly slightly to the left to loosen the spring

 
173

tension, then tighten the setscrew in the damper hub. Repeat this operation until the desired rheostat spring tension is obtained.

13G47. Checking the spider operation. (See Figure 13-47.) If the differential spider does not turn when the transmitter driven gear is slowed down, it is an indication that the follower tension spring is not adjusted properly. Tighten the follower spring, and observe the operation of the differential spider.

13G48. Checking the follower tension. (See Figure 13-47.) After checking the slipping clutch tension, and the rheostat spring adjustment, check the follower spring tension as follows: Place a finger on the driven gear of the distance transmitter, and stall the distance transmitter. If the follower tension is correct, the follower will drive the differential spider, the spider will turn the rheostat brush arm to its limit of travel, and the clutch will slip,

13G49. Final checks of the follower, differential, and rheostat assemblies. (See Figure 13-47.) After checking the operation of the follower, slipping clutch, and rheostat as described above, check the timing on the distance counter of the speed and distance indicator as described in 13044. If the measured time exceeds the tolerance of plus or minus 3 seconds, it is a positive indication that the central position of the follower on the rotating disk is incorrect. Check the follower as follows: Remove the note paper from the contacts, and return the pointer to the zero position. Unmesh the component frame upper gear as follows: Manually move the main balance arm until the setscrew and tapered pin are accessible; then slip the note paper under the contact arm to maintain the position of the pin and setscrew. Be certain to support the shaft when driving out the taper pin in order to prevent bending of the shaft. Carefully turn the follower lead screw toward the person facing the instrument, one bevel gear tooth for each 3 seconds or less that the measured time exceeds the 6 minutes for 1/2-mile. Turn the lead screw in the opposite direction in the same manner for every 3 seconds or less below the measured 6 minutes

  for the 1/2-mile indication. Carefully mesh the bevel gears at the right of the follower assembly, and tighten the setscrew in the component frame upper gear. Do not install the tapered pin at this time. Move the main balance arm until the lead screws turn to make the large end of the tapered pin hole accessible, then loosen the setscrew and install the tapered pin through the gear hub and the lead screw. Tighten the setscrew after the tapered pin is installed. Make the distance check described in Section 13G44. Then set the speed pointer at 20 knots, and repeat the time and distance check. The time elapsed. should be 6 minutes plus or minus 3 seconds for 2 miles distance indicated on the distance counter.

13G50. Removing the rheostat. (See Figure 13-48.) The 500-ohm rheostat is replaced as a unit. Remove the four screws and lock washers that secure the rheostat bracket to the main mounting plate, and lift the rheostat away from the mounting plate. Unsolder and tag the electrical leads. Loosen the setscrew in the damper hub while holding the rheostat shaft in position in the rheostat. It is necessary to hold the shaft in position to prevent the rheostat spring from ejecting parts from the rheostat. Remove the damper hub, spring, and frame assembly from the rheostat shaft. Remove the nut and toothed lock washer that secure the rheostat to the bracket, and remove the rheostat.

13G51. Installing the rheostat. (See Figure 13-48.) Carefully remove the lock washer from the shaft of the new rheostat while holding the shaft in position within the rheostat. This is necessary to prevent the internal parts from becoming lost when the washer is removed. Remove the nut and toothed lock washer from the replacement rheostat. Place the rheostat in its bracket and secure it with the toothed lock washer and nut provided. Align the damper hub of the damper spring and frame assembly with the flat-on end of the rheostat shaft, and tighten the setscrew in the damper hub. Place the rheostat and bracket in position on the main mounting plate, and secure them with the four screws

 
174

Figure 13-48. Rheostat removed.
Figure 13-48. Rheostat removed.
provided. Be careful to align the damper spring properly with the clutch plate. Solder the electrical leads to the terminal on the rheostat. Adjust the rheostat spring tension as described in Section 13G46.

13G52. Removing the component frame assembly. (See Figure 13-49.) Remove the log mechanism From its case. Place the mechanism on a bench, with the front of the log facing upward. Drive out the two locating pins as far as the main mounting plate so that the frame assembly will clear the force and balance arms. Remove the three screws that secure the component frame assembly to the mounting plate, and remove the frame assembly.

13G53. Replacing the bearings. (See Figure 13-50.) Scribe a locating mark on the component frame and the component slide so that the slide and frame can be held in the same relative position at assembly. Remove the tapered pin and loosen the setscrew from the component frame lead screw gear hub, and remove the gear. Remove the upper bearing clamp retaining screws and bearing clamp. Remove the shim, bearing, and bearing

  inner race from the recess in the component frame. The lower bearing is removed in the same manner. Install the bearing inner race in the recess in the component frame. Install the bearing and shim; then install the bearing clamp, and secure the clamp with the two screws provided. Place the component lead screw gear in position on the lead screw, align the hole in the gear hub and in the screw, install the tapered pin and tighten the setscrew in the hub. The bearing on the opposite end of the component frame is installed in the same manner.

13G54. Installing the component frame assembly. (See Figure 13-49.) Manually turn the gear on the component frame assembly until the scribe marks on the frame and slide are aligned. Place the component frame assembly in position on the front of the main mounting plate, and secure it with the three screws provided. Carefully drive in the locating pins from the back of the main mounting plate.

13G55. Removing the cam and bracket assembly. (See Figure 13-51.) Remove the case cover. Remove the pointer and dial. (See

 
175

Figure 13-49. Component frame assembly removed.
1. UPPER BEVEL GEAR
2. GEAR LOCK KNOB
3. B ADJUSTMENT KNOB
4. B SECTOR
5. SCRIBE MARKS
6. COMPONENT FRAME
7. LEAD SCREW
8. LOWER BEVEL GEAR
9. B ADJUSTMENT SCALE
Figure 13-49. Component frame assembly removed.

Section 13G2.) Scribe a locating mark on the speed transmitter drive gear of the cam and bracket assembly, and the speed transmitter driven gear on the speed transmitter so that the gears may be meshed in the same relative position at assembly. Remove the two screws that secure the cam bracket assembly to the mounting plate, and remove the cam and bracket assembly.

13G56. Disassembly of the cam and bracket assembly. (See Figure 13-52.) Remove the handle screw from the pointer hub, and remove the pointer hub. Remove the three screws and lock washers that secure the bearing clamp to the cam bracket, and remove the bearing clamp. Knock out the tapered pin and loosen the setscrew on the bearing collar. Pull the collar off the pointer shaft.

  Figure 13-50. Component frame assembly
partially disassembled.
Figure 13-50. Component frame assembly partially disassembled.

Remove the bearing from the recess in the cam bracket. Remove the nut, lock washer, flat washer, and bearing from the rear end of the pointer shaft. Scribe a locating mark on the cam and on the adjacent hub of the speed transmitter drive gear so that the cam may be installed in the same relative position at assembly. Remove the setscrew between the cam and helical gear, and remove the helical gear and cam as a unit. Loosen the setscrew in the speed transmitter drive gear hub, and remove the drive gear from the pointer shaft. Remove the three screws and lock washers,

 
176

Figure 13-51. Cam and bracket assembly removed.
Figure 13-51. Cam and bracket assembly removed.
  and knock out the pin that secures the cam to the cam hub, and remove the cam. Remove the three screws that secure the gear to the cam hub, and remove the gear.

13G57. Assembling the cam and bracket assembly. (See Figures 13-52 and 13-51.) Place the cam on the cam hub, using the scribe mark as a reference, and secure it with the three screws and pin provided. Install the helical gear on the cam hub, and secure it with the three screws provided. Place the speed transmitter drive gear on the pointer shaft, and install the handle screw. Place the bearing in the recess in the bracket, and install the bearing clamp. Place the pointer shaft in the bracket, install the cam and hub assembly on the pointer shaft, and install the handle screw. Install the bearing collar on the long end of the pointer shaft, and tighten the setscrew in the nearing collar. Install the pointer hub, and secure with the handle screw. Place the bearing on the threaded end of the pointer shaft, and install the flat washer, lock washer, and nut.

Figure 13-52. Cam and bracket assembly disassembled.
1. HANDLE SCREW
2. POINTER HUB
3. FILLISTER-HEAD SCREW
4. LOCK WASHER
5. BEARING CLAMP
6. TAPERED PIN
7. BEARING COLLAR
8. SOCKET HEAD SETSCREW
9. BEARING
10. CAM BRACKET
11. SPEED TRANSMITTER DRIVE GEAR
12. SHAFT
13. HANDLE SCREW
14. CAM
15. DOWEL PIN
16. HUB
17. HELICAL GEAR
18. FLAT HEAD MACHINE SCREW
19. FLAT WASHER
20. NUT

Figure 13-52. Cam and bracket assembly disassembled.
 
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13G58. Installing the cam and bracket assembly. (See Figure 13-51.) Place the cam and bracket assembly in position on the main mounting plate with the transmitter drive and driven gears meshed according to the scribe marks made on the gears when they were removed. Install the two screws and dowel pin that secure the cam and bracket assembly to the main mounting plate. Install the dial and pointer.   13G60. Disassembling the power motor transmission shaft assembly. (See Figure 13-53.) Remove the bearing clamp, dust washer, and bearing from the left bearing block. Remove the nut, lock washer, and flat washer from the right end of the shaft. Remove the tapered pin and loosen the setscrew that secures the shaft driving gear to the shaft, and remove the gear. Remove the dust ring and bearing from the right bearing block. Remove
Figure 13-53. Power motor transmission shaft assembly disassembled.
Figure 13-53. Power motor transmission shaft assembly disassembled.
13G59. Removing the power motor transmission shaft assembly. (See Figure 13-53.) Remove the cam and bracket assembly. (See Section 13G55:) Remove the nut, lock washer, and flat washer from the left end of the shaft. Remove the left bearing block from the mounting plate by removing the two block retaining screws. Remove the two screws from the right bearing block and pull the right bearing block and the shaft assembly to the right and away from the mounting plate.   the bevel gear from the shaft by knocking out the tapered pin and loosening the setscrew in the gear hub. Knock out the two tapered pins that secure the worm on the shaft, and remove the worm.

13G61. Assembling the power motor transmission shaft assembly. (See Figure 13-53.) Place the worm over the shaft, align the holes in the worm and shaft, and install the two tapered pins. Place the bevel gear on the right end of the shaft, with the gear teeth toward the worm, install the tapered pin and tighten

 
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the setscrew in the gear hub. Place the bearing in the right bearing clamp. Insert the end of the shaft into the bearing and install the dust ring adjacent to the bearing. Place the drive gear on the shaft, with the gear hub facing the end of the shaft, and install the tapered pin. Install the flat washer, lock washer, and nut on the right end oF the shaft. Install the bearing in the left bearing block. Install the dust washer and bearing clamp in the left bearing block, and secure the clamp with the two screws provided. Insert the shaft assembly under the main balance arm and force arm assemblies, from right to left, and insert the end of the shaft into the left bearing block. Secure the bearing block to the mounting plate with the two screws provided. Align the right bearing block on the mounting plate and install the two screws that secure the bearing block to the mounting plate. Install the flat washer, lock washer, and nut on the left end of the shaft. Install the cam and bracket assembly. (See Section 13G58.)

13G62. Removing the main force arm. (See Figure 13-54.) Remove the log mechanism from the case. Remove the earn and bracket assembly. (See Section 13G55.) Unscrew and remove the spring thimble and adjusting screw assembly from the top of the spring barrel assembly of the A-adjustment mechanism. Insert the short screwdriver within the spring barrel, unscrew the connector screw that joins the A-mechanism with the rocker of the auxiliary balance arm, and remove the A-adjustment mechanism. From the back of the main mounting plate, remove the nut and flat washer that secure the main force arm shaft to the main mounting plate, and remove the main force arm. The force load spring is removed from the main force arm shaft when the assembly is lifted away from the mounting plate.

13G63. Disassembly of the main force arm. (See Figure 13-55.) Remove the four screws (two on each side) that secure the bearing clamps to the top of the main force arm, and lift off the bearing clamps and the A-adjustment mechanism from the main force arm. Remove the nut, lock washer, dust washer,

  Figure 13-54. Main force arm removed.
Figure 13-54. Main force arm removed.

and bearing from one side of the A-adjustment axle. The bearing on the opposite side of the axle is removed in the same manner. Remove the nut, lock washer, and dust washer from the front of the main force arm shaft, and pull the shaft to the rear and out of the main force arm. The rear dust washer is removed with the main force arm shaft. Remove the two bearings and bearing spacer from the force arm.

13G64. Assembly of the main force arm. (See Figure 13-55.) Place the rear bearing in the recess in back of the main force arm. Place the rear dust washer in position on the rear of the main force arm shaft. Hold the

 
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Figure 13-55. Main force arm partially disassembled.
1. FILLISTER HEAD SCREW.
2. LOCK WASHER.
3. BEARING CLAMP.
4. A ADJUSTMENT ASSEMBLY.
5. DUST WASHER.
6. NUT.
7. BEARING.
8. CONNECTOR SCREW.
9. MAIN FORCE ARM.
10. BEARING SPACER.
11. COUNTERWEIGHT.
12. BEARING PIN.
13. CAM FOLLOWER.
14. MAIN FORCE ARM SHAFT.
15. FORCE LOAD SPRING.

Figure 13-55. Main force arm partially disassembled.
bearing spacer in position within the force arm, and carefully insert the main force arm shaft from the rear of the arm, through the rear bearing and spacer to the front end of the arm. Install the front bearing, dust washer, lock washer, and nut on the front end of the main force arm shaft. Install the bearing, dust washer, lock washer, and nut on one side of the A-adjustment axle. The bearing on the opposite side of the axle is installed in the same manner. Place the A-adjustment mechanism in position on top of the main force arm, install the two bearing clamps, and secure each clamp with the two screws and lock washers provided.

13G65. Installing the main force arm. (See Figure 13-54.) Place the force load spring on the rear end of the main force arm shaft, with the offset in the spring engaged in the slot of the main force arm. Carefully place the main force arm in position on the main mounting plate, with the main force arm shaft inserted through the opening provided in the mounting plate and with the spring end also engaged in the hole provided in the mounting plate. Install the flat washer and nut that secure the main force arm shaft to the main mounting plate. Install the connector screw of the A-adjustment assembly into the rocker in the top of the auxiliary balance arm. Install the spring thimble and adjusting screw into the spring barrel of the A-adjustment mechanism. Calibrate the instrument. (See Chapter 15.)

13G66. Removing the auxiliary and main balance arms. (See Figure 13-56.) Cut the string that secures the electrical lead to the main balance arm. Remove the three screws and lock washers that secure the auxiliary and main balance arm assembly to the main mounting plate. Lift the assembly upward, and turn it sideways to make the electrical lead to the contact arm accessible. Unsolder the electrical connection from the terminal on the contact arm, and remove the auxiliary and main balance arm assembly.

13G67. Disassembly of the auxiliary and main balance arm assembly. (See Figure 1357.) Remove the lock nut and thin nut from top of the B-spring, and disengage the spring

 

Figure 13-56. Auxiliary and main balance arm
assembly removed.
1. INDEX SCREW
2. B SPRING
3. GUIDE BEARINGS
4. CONNECTOR SCREW
5. THRUST PLATE
6. FRONT SECTION AUXILIARY BALANCE ARM
7. MAIN BALANCE ARM
8. CONTACT ARM
9. AUXILIARY BALANCE ARM CENTER SUPPORT
10. MAIN FORCE BEARING, ASSEMBLY
11. MAIN BALANCE ARM ADJUSTING SCREWS
12. COUNTERWEIGHT
13. BEARING CLAMP
Figure 13-56. Auxiliary and main balance arm assembly removed.

 
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Figure 13-57. Auxiliary and main balance arm partially disassembled.
1. LOCK NUT
2. THIN NUT
3. B SPRING
4. CONNECTOR SCREW
5. SPRING FORCE HUB
6. NUT
7. DUST WASHER
8. BEARING
9. BEARING SHAFT
10. DOUBLE DUST WASHER
11. AUXILIARY ARM EXTENSION
12. LOCK WASHER
13. FLAT WASHER
14. FILLISTER-HEAD SCREW
15. FRONT SECTION OF AUXILIARY BALANCE ARM
16. SHIM
17. CONTACT ARM ASSEMBLY
18. THRUST PLATE
19. ROCKER BEARING
20. FLATHEAD MACHINE SCREW
21. MAIN BALANCE ARM
22. COUNTERWEIGHT
23. MAIN FORCE BEARING ASSEMBLY
24. BEARING CLAMP
25. SPACER
26. MAIN BALANCE SHAFT
27. ROCKER
28. REAR SECTION OF AUXILIARY BALANCE ARM

Figure 13-57. Auxiliary and main balance arm partially disassembled.
 
182

from the auxiliary balance arm. Unscrew and remove the B-spring connector screw from the rocker. Remove the two screws (one on each side) that secure the thrust plates to the rocker bearings and remove the thrust plates. Remove the two screws that secure the rocker bearings in the main balance arm, and remove the bearings and rocker from the top of the main balance arm. The other rocker and the bearings at the top of the main balance arm are removed in the same manner. Remove the two bearing clamp retaining screws and bearing clamp from the front of the main force bearing assembly. Remove the hexagonal nut from the front of the main balance shaft; then pull the main balance shaft to the rear and out of the: auxiliary and main balance arms. Remove the bearing, shim, and spacer from the front end of the balance shaft as the shaft is pulled to the rear. Lift the main force bearing assembly (bracket) away from the arm assembly. Remove the dust washer, spacer, second dust washer, shim, and bearing from the recess in back of the main force bearing. Remove the screw that secures the two sections of the auxiliary balance arm at the center support. Remove the two screws that secure the two sections of the auxiliary balance arm at the top of the arm. Remove the nut, lock washer, and dust washer from each end of the spring force hub. Carefully pull the two sections of the arm apart.

The two sections of the auxiliary balance arm are pinned together, and the sections must be pulled straight away to prevent bending the pins.

Remove the bearings and spring force hub. Remove the nut and lock washer that secure the guide bearing assembly to the end of the auxiliary balance arm, and remove the bearing assembly. Remove the dust washer, bearing and double, dust washer from the bearing shaft. Remove the nut, rear dust washer, and second bearing from the other end of the bearing shaft. Remove the screw that secures the contact arm assembly to the main balance arm, and remove the contact assembly.

13G68. Assembly of the auxiliary and main balance arm assembly. (See Figure 13-57.)

  Mount the rocker assembly at the top of the main balance arm in the following manner: Install one rocker bearing in one side of the recess at top of the main balance arm. Place the rocker in approximate position in the installed rocker bearing. Place the second rocker bearing in approximate position on the opposite side of the main balance arm. Secure the rocker bearings to the main balance arm with the two screws provided (one on each bearing). Place the thrust plates in position on the outer sides of the rocker bearings (one on each bearing) and secure, with one screw for each thrust plate. The other rocker assembly is installed in the same manner.

Align the B-spring with the rocker, and tighten the connector screw in the rocker. Place both sections of the auxiliary balance arm in approximate position on each side of the main balance arm, and place the spring force hub between the upper sections of the auxiliary balance arm, with the long section. of the force hub upward. Align the pin holes and pins of the two sections of the auxiliary balance arm, and squeeze the two sections together into position on the main balance arm. Secure the auxiliary balance arm at its center support with one screw, and at the top of the arm with two screws. Install the bearing, dust washer, lock washer, and nut on each end of the spring force hub. Install a bearing in each of the two sections at the bottom of the auxiliary balance arm. Place the main force bearing assembly (bracket) in position at the bottom of the auxiliary and main balance arms.

Assemble the bearing, dust washer, spacer, second dust washer, and shim, in that order, on the back of the balance shaft. Align all parts and carefully insert the balance shaft from the rear of the main force bearing through the auxiliary and main balance arms far enough to install the shim and outer dust washer on the front end of the balance shaft. Completely insert the balance shaft through the auxiliary and main balance arm assemblies. Install the spacer, shim, and bearing on the front end of the balance shaft. Install the hexagonal nut on the front end of the shaft. Install the bearing clamp on the forward side

 
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of the main force bearing (bracket), and secure the bearing clamp with the two screws provided. Install the guide bearings as follows : Assemble the dust washer, and bearing on the short threaded end of the bearing pin. Assemble the double dust washer, second bearing, and dust washer from the other end of the bearing pin. Install the bearing pin, with its assembled bearings, through an opening in the arm extension at the top of the auxiliary balance arm, and secure it with a nut on the front end of the bearing pin. Place the B-spring assembly into the spring force hub, and install the thin nut and lock nut on top of the B-adjustment assembly. Install the contact arm assembly in position on the main balance arm, and secure it with one screw.

13G69. Installing the auxiliary and main balance arms. (See Figure 13-56.) Place the auxiliary and main balance arm assemblies in approximate position on the mounting plate. Solder the electrical lead to the terminal on the contact arm assembly. Install the three screws and lock washers that secure the auxiliary and main balance arm assemblies to the main mounting plate. Align the electrical lead along the main balance arm and secure it in position with string. Install the main force arm (see Section 13G65). Install the cam and bracket assembly (see Section 13G58). Calibrate the instrument as described in Chapter 15.

13G70. Replacing the contact arm. (See Figure 13-58.) The contact arm and contact are replaced as a unit. Remove the cover from the master transmitter indicator case. Unsolder the electrical lead from the contact arm

  Figure 13-58. Contact arm assembly removed.
Figure 13-58. Contact arm assembly removed.

terminal. Remove the screw that secures the contact arm to the main balance arm, and remove the contact arm assembly. Unhook the contact spring from the contact arm. Remove the pigtail from the contact arm. Loosen the setscrews that secure the pivots in the contact arm bracket, loosen the pivots, and remove. the contact arm and shaft as a unit. Place the new contact arm in position, and tighten the pivots. Tighten the setscrews. Install the pigtail on the contact arm. Engage the contact spring on the end of the contact arm. Place the contact arm assembly in position on the main balance arm, and install the arm retaining screw. Solder the electrical lead to the terminal on the contact arm bracket.

 
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