White Paper Discuss: 2 speed, Shift-on-the-fly TechnoKat Gearbox

[dlavery]

Originally posted by Andy Baker
This points out one thing I forgot to include in the write-up. Mounting the drill motor was not as easy as the prints show. We altered the drill motors a bit in order to make them mountable. Very carefully, we threaded the two holes on the front face of the drill motor for M5x0.8 screws.

Andy -

As always, your transmission design and plans are superb.

The approach we took with the drill motors this year was to use two short #10 machine screws in the face plate of the motor mount (i.e. they projected through the small holes in the face of the motor, similar to the plastic pins in the original drill transmission). To retain the motor against the face plate, we used small "J-hooks" made out of 1/4" drill rod that ran from the face plate, along the sides of the motor, to the square notches at the rear of the motor housing. The screws/pins prevented rotation, and the J-hooks prevented lateral motion of the motor. It was very easy to fabricate, and we didn't have to try to tap the holes in the face plate of the motor (I was really concerned about getting chips into the windings), and proved to be pretty robust (we never had a motor torque out of place, and we beat on it pretty hard).

I will post a set of drawings in a few days, as soon as I get them cleaned up. We updated our transmission design for the 2003 larger drill motors, and had good success with it in Annapolis. The design is still bigger and clunkier that the Teknokat transmission, but doesn't require CNC for fabrication (for those of us still limited to manual mills and lathes ).

-dave