Posted by Joe Johnson. [PICTURE: SAME | NEW | HELP]
Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.
Posted on 1/20/2000 6:18 PM MST
Follow the link below for a sketch of a robust method of getting torque out of the business end of a drill transmission.
Some notes:
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The length of the shaft is arbitrary, shorten it to suit your application.
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No proper tolerances – so shoot me 
Basically the only fussy dimensions involve the position of the pins for the planets and the press fit for the pins you will have to press out of the part from the transmission. Give the old part to the machinist and ask for a ‘tight press fit’ let him pick go from there.
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Depending on your application you may not need the groove for the ring clip. If your application does not allow a thrust load to push the shaft toward the transmission, you may be able to get away without using it (and of course the balls that it retains).
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The thumbnail picture below is not readable. Follow the link below the thumbnail picture to view a better picture.
Have questions, e-mail me.
Joe J.
Posted by Joe Johnson. [PICTURE: SAME | NEW | HELP]
Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.
Posted on 1/20/2000 6:28 PM MST
In Reply to: Sketch of shaft for Robust Drill Transmission posted by Joe Johnson on 1/20/2000 6:18 PM MST:
One more thing, once you have this nice round shaft to connect to, I recommend that you use a 12mm Trantorque from Small Parts Inc. to lock a sprocket or gear to this shaft.
All you need is a 22.5mm hole in the sprocket or gear and you are in business.
Also, make sure you use a metals sprocket or gear. A plastic one will not provide the hoop strength needed to make the inner side of the Trantorque clamp onto the 12mm shaft with sufficient gusto.
Finally, I recommend that you support this new shaft with two bearings (one on each side of the Trantorque). If you do this, the job of supporting the beautifully sculpted but difficult to mount drill housings is a snap. The two bearings support the drill, all you have left to do is keep it from rotating. Not a brainless task but with thought can be done well with ease.
Good Luck to all.
Joe J.
Posted by Daniel.
Coach on team #483, BORG, from Berkeley High School and NASA Ames & UC Berkeley.
Posted on 1/21/2000 3:01 PM MST
In Reply to: Sketch of shaft for Robust Drill Transmission posted by Joe Johnson on 1/20/2000 6:18 PM MST:
Look for your design (plus small variations) on team 483’s ‘BUM’ this year. I had worked out a much more complicated way of doing the same thing…so thanks!
-DL