pic: 222 3 speed closeup/cutaway

[tkwetzel]

Also, any generic advice on building trannys would be great. We have limited machining capabilities (no high tech stuff i.e. CNC etc.).

There are a few white papers on trannys on this site. There are many good white papers. Our team has posted a white paper for our 2-motor, 2-speed gearbox, that only requires a manual mill and lathe to create.

Another good and simple gearbox is team 33's 4-speed automatic gearbox this year. I don't know that there is a white paper available for it, but you might be able to get a lot of information from them about it. It supposedly can be made with a lathe and a drill press with an X-Y table.

Just some suggestions. There are tons of designs out there, as you can see by the variety just this year. A lot of it sometimes depends on the game. Good luck with your offseason work!

[jskene]

I am planning to build one of your transmissions in the off-season, and hopefully develop an automatic shift algorithm for it, which of course I will share on this discussion board. I have a few (actually, several) questions on your design:

1. It looks like you have used a fairly thick walled 1" diameter tube as the main axle. Was this machined out of a 1" rod?
2. What material did you use?
3. What diameter is the inside hole?
4. How far out to the 5/16" ball bearings protrude when they are pushed out by the inner ring?
5. Do you need to have two sizes of holes on the axle to prevent the balls from going in too far? Could you not just have the balls drop down and touch the spring?
6. Does the shifter rod rotate with the axle, and if so, how do you push or pull on it?
7. It seems that the balls might have a tendency to push themselves out due to the rotation of the axle, or at least drop down into a lower notch in a gear when the axle is at rest due to gravity. Do you have any problem with the balls coming out prematurely into the wrong gear?
8. How much force is needed to push the shifter ring against a set of balls to select the next gear?
   

Sorry to have so many questions, but I am quite interested in this design you have some up with, and want to experiment with it. I think it shows great promise for future development.