TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
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TM 9-1240-401-34&P 4-21. COUNTER BOX ASSEMBLY (COUNTERS) MAINTENANCE INSTRUCTIONS - continued c. Assembly - continued 5 6 7 8 9 10 11 12 13 14 15 Install correction knob (35) (ref. para 4-17). NOTE Perform steps 6 thru 12 if new elevation rotat ing counter is installed. If reinstalling existing elevation rotating counter (29), go to step 13. Temporarily install a setscrew in gear (33) and slide gear (33) onto shaft of elevation rotating counter (29). Secure elevation rotating counter (29) to base (36) using four new Iockwashers (28) and four machine screws (27). Drill two pilot holes approximately 1/16 inch (0.16 mm) deep into base of elevation rotating counter (29), ensuring that drill bit does not damage numer- als or elevation rotating counter (29) shaft. Remove elevation rotating counter (29) from base (36) and finish drilling holes in elevation rotating counter (29). Drill, ream, and pin gear (33) to shaft of elevation rotating counter (29) using tapered pin (32). Install mask (31) on elevation rotating counter (29) and secure with two machine screws (30). Install two headless straight pins (34), into base (36). Rotate correction knob (35) counterclockwise to stop. Set elevation rotating counter (29) to an indication of -50. Install elevation rotating counter (29) on base (36) and secure with four new lockwashers (28) and four machine screws (27). 4-42