pic: GBX-127, bevel-beside-wheel swerve drive

[asid61]

Originally Posted by R.C.

Gotcha,

If you are using a s4, how are you zero'n it?

http://puu.sh/jxgeU/4eb20e2530.png

Hopefully this shows how we did it, we used the tube axle by VEXpro and used r6-5zz bearings. The forks also had a recess for the tube axle to sit into and it was held in with a 1/4" bolt. We liked this layout but we will be updating the use of the R6-5zz bearings to a metric flanged bearing to retain the wheel better. Atm the wheel can slide off the bevel gear, while it never happened during season it did happen to one of our pbot wheels.

Unsure how thick your forks are as well, we did .5" thick and had room for an 11mm OD bearing. Also used a thrust washer this year, will most likely be switching to a thrust roller bearing.

-RC

I was thinking of a hall effect sensor for zeroing, but we haven't tested the precision on that yet so we need to do that first. I will put the magnet and stuff into the CAD as well.

I can see that; I didn't think of putting the bearings in the face of the bevel gear rather than in the hub! A 1/4" bolt, spacer and flanged bearings should work if you used them and had success too.
Then the only question is how easy it is to bore out the gear rather than the side plates, and we just need to test that once we get our new lathe.
I don't want to move to 1/2" plates for weight and waterjetting purposes (we'd have to waterjet a single 1/2" plate for the whole bot), although I went up to 3/8" already due to the way the bevel gear is set up. I can try putting in a 1/4" OD bushing or something, but switching to a thrust washer should remove the need for one by reducing cantilever. I need to test this out on a module to be sure; it's always possible to upgrade just the forks. I love this design; it's very modular.
Did you experience any issues with the thrust washer, or did you just see the beginning of issues like minor wear? I used a McMaster 7806K63, but it's very thick and increases the cantilever on the gear by a whole lot.

EDIT: Actually putting the bearing in the bevel gear in the hub would make it impossible to machine for us... good thing a face mount is possible.