Ultimate Omni Wheels

The Ultimate Omni-Wheels .. V2!

• Standard omni wheels have two side-by-side wheels made of rollers.
• Ultimate omni-wheels have a single row of rollers. How? Rollers inside rollers!

This is my fancy design, made into my friendly neighborhood robot, Dug! His code is here on github!

Living design

This is a living design. I've designed it parametrically so it's easily adapted to any parameters. Please reach out if you're interested in this, I'd like to help you adapt this for your motors/bearing/sizing!

• Join my 3D Design discord Robotics Channel! Say hi!

V2 is live!

V2 is out! It uses a bolt+bushing axle for the small rollers (instead of bearings) which allows for the wheel-holder to be a single-piece, far stronger part! It's also cheaper to build (requires half the bearings)

Hardware: Each omni-wheel needs

1. Bearings: 10x 8x14x4 mm Uxcell MR148-2RS / MR148ZZ or similar bearings!
   1. That's: 14mm OD, 8mm ID, 4mm. These are small, cheap, highly available, and great!
   2. See [amazon] or maybe these [aliexpress]
   3. The design can be reworked for other bearings. Reach out!
2. Axle bolts: 5x M3x45. like these [amazon]
3. Bushings: Two options
   1. 10x M3 Nylon Flange-Bushings [amazon] [aliexpress (TW6)]
   2. Full-length coper tube as bushings. Can be made from hardware store coper tubing.
4. Holder bolts: 5x M3x20 countersink for holding the roller-holders on to the hub.
5. Drive bolts: 3x M4x20 countersink bolts for mounting to the motor.. Has space for 6x but that's overkill.
   1. This is motor-specific! See the Motors section below.

Materials / print settings:

• TPU flexible filament:
  • 5x small rollers, 5x big rollers
  • TPU gives the best grip. Alternatively use a rigid filament and coat lightly with plasti-dip.
  • Use fuzzy-skin feature in your slicer for more grip!
  • 95A is fine, 92A has more grip.
• Rigid filament
  • 10x holder parts. Use as strong/durable filament as you've got! PETG-CF, Nylon, etc.
  • 1x hub part. Regular PETG is fine here.

Motors:

1. MIT Mini-Cheetah style planetary gear motor drive motors

   1. Xiaomi CyberGear motors, ~$90US each.
      I used these fancy brushless integrated-drive+gearbox mini Xiaomi CyberGear Motors [aliexpress]

      They're incredible, though proprietary and not exactly inexpensive. Can't argue with their 12N/m of torque and their cost compared to others.

      1. You'll want some sort of connector like these “AMASS XT30(2+2)-F” on [aliexpress]
   2. Steadywin GIM6010-8 5N/m, ~$100US each.
      These look great, use an ODrive derived controller, and are more customizable. [aliexpress]
      1. Also supported with my omnictrl project since they're odrives!
   3. Actual Mini-Cheetah drives cost $400+
2. DC Motors
   1. Would be much cheaper! .. but lower performance. Needs gearbox.
   2. Needs investigation for how to handle their D-style shafts for a 3d-printed hub.
3. Stepper Motors
   1. Also cheap! High torque + speed. No reduction needed.
   2. Same D-style shaft issue.

Interested in using different motors? Message me in my 3D Design discord under the Robotics Channel!

Parts list: making a omni-wheeled robot like Dug!

1. Microcontroller: Recommend the M5Stack AtomS3 [M5Stack]
2. CANBus transceiver. Recommend the M5Stack Mini CAN Unit. It's got built-in voltage regulation for the microcontroller, it's easy to assemble with screw-terminals, and comes with the wire/connector for the AtomS3. [M5Stack]
3. Print 3x motor-bracket parts. PLA or PETG is fine.
4. 4x M3x8mm countersink bolts per motor to mount the motors to the brackets.

Software: t413/omnictrl!

• Github page!
• That's it!

Make one? Considering it? Taking inspiration?

• Reach out! Say hi!
• Leave a comment!
• Say hi in my 3D Design discord Robotics channel!