[Scott Kozutsky]

Originally Posted by Chris is me

Another thing - I don't really like the lightening pattern on the gear. The spokes don't do a ton for the gear's strength, and a spoked lightening pattern like that requires milling whereas a no-spoke lightening pattern could potentially be turned.

If you are going to do a spoked lightening pattern, at least make it six spokes and have the spokes align with the hex points. That way the additional material is behind the stress risers and not just in random places.

In either case, I would leave a bit more material around the hex (maybe .875 diameter?). The material left around the gear teeth should be fine. If the thin part of the gear is at least .15 thick or so you should be fine. These are "gut numbers" not backed up by real math or engineering, just experience, so take them with a grain of salt.

The design assumed use of a CNC router so that would be used to do the pockets (multiple passes, depth of cut isn't that great but its certainly doable). I also made sure not to pocket it all the way through so there is 1/16 of material left on the bottom which should adequately handle the torsional shear between the hex and the teeth. The diameter of material surrounding the hex is .8 which should be ok as there will be relatively less stress acting on it (3.25in omni wheels can only transmit so much torque compared to 4 in nitrile for example). 7 spokes is a byproduct of our team name, not the best engineering solution but we'd probably keep it anyways.