pic: Two Speed Flipped CIM Gearbox



My attempt at a compact two speed flipped CIM gearbox. I’m not sure how I feel about the pneumatic arrangement yet. 6.9 fps in low and 15.3 fps in high at free speed. Questions and comments are welcome.

Where are you sourcing those first stage gears from? They don’t look like standard 20DP gears from Vex or AM.

Also how are the pneumatic cylinders’ bodies attached to the assembly?

The driving gear is this one from AM.

The driven gear is this 64t one from WCP. (with additional lightening for fun)

Also how are the pneumatic cylinders’ bodies attached to the assembly?

With 0.25" spacers and 6 32 bolts. They are bolted right to the drive rail.

Love the design - Bryce! Your rear plate doesn’t need to contour around the CIMs, so you can save some weight by only putting material between the motors to connect to the standoff in the middle. It also makes for a (imo) much sleeker look.

Very interesting. I can’t say I enjoy those pneumatics, but apart from that it looks very sleek.
Would you be able to make the shifter move the dog directly? That also saves you the effort of making a plunger system (and replaces it with a larger bearing around the dog).

Thanks! I’ll see how it looks.

I’m not really sure what you mean by this. There is no dog in this design. It is a ball shifter.

Whoops, didn’t notice that in the other pic. If that’s the case, you could switch to a dog shifter and then move the dog directly. :stuck_out_tongue:
The main issue with the way the pneumatics are now is that it forces you to put the bumpers farther out than they would be with just the wheel, which is reducing your between-drive-rails space and partially defeating the purpose. I suppose having the CIM out there already does that, but this is an odd case where I would actually want the CIMs inboard more to pull the bumpers in some.