Yoke Rebuild

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Revision as of 23:52, 6 October 2007 by Majorrockhardy (talk)
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This page is a documentation of a complete teardown, refurbish (paint & lube), and rebuild of an Atari Star Wars type yoke control.

A superb scan of a Star Wars Operator's Manual (in .pdf form) is available here: http://www.gamearchive.com/Video_Games/Manufacturers/Atari/onlinemanuals/starwars_op_manual.pdf (see pages 42 & 43 of the pdf for the yoke exploded view) (I will use most of Atari's parts nomenclature.)

Replacement parts now available at RAM Controls: http://www.ram-controls.com/order-sw.html


Also, a source for METAL replacement gears is W.M. BERG: http://www.wmberg.com/

NOTE: I have not tested these gears for compatibility and some (specifically the 60 tooth gears) would at least require drilling out the bore to accommodate the diameter of the steering/handle shafts, but the following are my best estimates as to replacement gear part numbers:

14 tooth Y-axis pot gear: P24A66-14 (in ANODIZED ALUMINUM) or P24PH28-14 (in STAINLESS STEEL)

28 tooth X-axis pot gear: P24PH28-28 (in STAINLESS STEEL)

60 tooth X/Y-axis shaft gear: P24B34X-60 (BRASS or BRONZE - it's unclear) or P24A68-60, P24A67-60, P24A66-60 (in ANODIZED ALUMINUM) or P24S35-60, P24S34X-60 (in STAINLESS STEEL)

... but do your homework and make sure these will work before ordering.



The Guide

NOTE: Wires, potentiometers (pots), and microswitches may differ from original. This guide also assumes you have already removed the outer cover.

SAVE EVERYTHING YOU REMOVE FROM THE YOKE (EVEN IF REPLACING) UNTIL IT IS REBUILT


Step 1: Loosen X-axis pot retainer nut with 1/2" wrench. Remove shoulder bolt from X-axis pot 28-tooth spur gear hub using allen wrench. Remove spur gear from pot.

Yoke rebuild1.jpg


Step 2: Remove X-axis pot retainer nut and star washer. Remove Pot.

Yoke rebuild2.jpg


Step 3: Remove shoulder bolt from X-axis shaft 60-tooth spur gear hub using allen wrench. Remove spur gear from shaft.

Yoke rebuild3.jpg


Step 4: Remove C-clip using flathead screwdriver.

Yoke rebuild4.jpg


Step 5: Remove shaft washer.

Yoke rebuild5.jpg


Step 6: Loosen anchor pin using 5/16" wrench or socket. Hold anchor nut using another 5/16" wrench

Yoke rebuild6.jpg


Step 7: Remove anchor pin and nut. Rotate steering assembly frame while doing so to relieve spring tension on pin and nut.

Yoke rebuild7.jpg


Step 8: Slide torsion springs and steering assembly frame off the steering shaft.

Yoke rebuild8.jpg


Step 9: Remove bump stops (if they exist) from metal pins on steering assembly frame and handle assembly frame (4 total).

Yoke rebuild9.jpg


Step 10: Remove white plastic bushing from steering shaft.

Yoke rebuild10.jpg


Step 11: Remove shoulder bolt from handle assembly frame steering shaft hub using allen wrench. 3 total (one on underside).

Yoke rebuild11.jpg


Step 12: Remove steering shaft from handle assembly frame.

Yoke rebuild12.jpg


Step 13: Loosen Y-axis pot retainer nut with 1/2" wrench. Loosen set screw from Y-axis pot 14-tooth spur gear hub using allen wrench.

Yoke rebuild13.jpg


Step 14: Remove spur gear from pot. A 3/8" wrench is handy as a gear puller.

Yoke rebuild14.jpg


Step 15: Remove bolt from Y-axis shaft limiter pin using allen wrench. Rotate handles while doing so to relieve spring tension on pin.

Yoke rebuild15.jpg


Step 16: Remove outer and inner shoulder bolt from handle hub using allen wrench.

Yoke rebuild16.jpg


Step 17: Wonder why the handle won't come off. Wonder what that other thing is between the outer and inner shoulder bolt holes. Realize it is a pressed-in spring pin. Ponder how to get it out.

Yoke rebuild17.jpg


Step 18: Cut wires free from microswitches. Pull wires back through handle shaft. Remove microswitch bolts using screwdriver and remove microswitches. Use screwdriver inside handle shaft to push spring pin outwards.

Yoke rebuild18.jpg


Step 19: Grip spring pin with vise grips and pull. Repeat until spring pin actually comes out. At some point, you may be able to rotate it a bit while pulling.

Yoke rebuild19.jpg


Step 20: Marvel at the fact you have triumphed over an inanimate 4 cent piece of steel. Repeat steps 16-20 for other handle (if you want/need to - the other handle could stay on the handle shaft). TIP: I was finally able to get the second spring pin out by gripping it in the edge of a vise with a good sharp edge on the jaw and put sandpaper in between the vise jaw and the pin for extra grip. Remove shoulder bolt from Y-axis shaft 60-tooth spur gear hub using allen wrench. Remove C-clips using hook pick or other tool, but be extremely cautious if prying with a screwdriver as it would be too easy to damage the plastic (but expensive to replace) gear. Slide handle shaft out of handle assembly frame and torsion springs. Remove torsion springs. Pick out gear that has been freed.

Yoke rebuild20.jpg


Step 21: Gently tap handle shaft bearing towards interior of handle assembly frame using hammer.

Yoke rebuild21.jpg


Step 22: The ball end on my screwdriver worked well to free the bearing from the handle assembly frame.

Yoke rebuild22.jpg


Step 23: Strip paint off the handles, handle assembly frame, and steering assembly frame. Bead blasting worked great for me. One of my handles had a nick out of it - I'm guessing this was a casting flaw. I patched it with JB Weld and sanded it down. (WARNING: NAKED YOKE!) Stripped yoke parts.jpg