Bánh xe Mecanum 70mm

We needed a 70mm mecanum wheel.  

This is a remix of a previous, larger mecanum wheel we used on Tigerbot in 2018 PiWars. https://www.thingiverse.com/thing:3127629 

Original inspiration came from https://www.thingiverse.com/thing:1358552 

Commercially available mecanum wheels are wide and expensive.  This one is designed to be thin (to fit into the PiWars width limit) and inexpensive - the roller axles are 25mm dressmakers pins.  

We weren't sure at the time of designing these what motors we would be using, so the wheel features a hub adaptor that adapts the motor to the wheel.  The current adaptor mounts on a 3mm D-shaped shaft.  A brushless gimbal motor GM3506 from here: https://shop.iflight.com/ipower-motor-gm3506-brushless-gimbal-motor-pro967?search=GM3506 should fit into the wheel without the adapter.

The wheel was designed in OnShape, you can get access to the CAD model to remix it here: https://cad.onshape.com/documents/745b1b07ac6a7c1356088ae4/w/b7cf1a55dc93fc40a15c6c1a/e/6dcf43a4cd23d5dae5db001d?renderM

I print the wheel frame and hub in PETG (but have used PLA also), the rollers in TPU.  The rollers need to be printed one at a time (sequential printing - complete individual objects) with a large spacing between to avoid stringing between them and get a good surface finish.  I can fit 12 at a time on my Prusa MK2.5S bed.

The frames print in halves - frame 1&2 go together and 3&4 go together.  The 2 frames are mirror images of each other (needed to make mecanum wheels work on a 4-wheeled robot).