Omniwheel (Rezero style)

Omnidirectional wheel for robotics projects with 100mm wheel radius. Rollers use double bearings for a smooth rolling experience in normal direction.

The design is the recreation of the ingenious design used by the Rezero Ballbot. Thanks to this article, the basic principles are visible:
https://spectrum.ieee.org/automaton/robotics/industrial-robots/omniwheels

Using FDM printed centerpieces, the assembly process requires post processing for all holes for a proper fit!

Some of the files might change based on further testing!

The WheelRim fits the output shaft of the metal gearbox available here:
https://www.ebay.com/itm/DC12V-Gear-Box-Motor-Encoder-Code-Disk-10rpm-1-600-Speed-Reduction-6mm-D-Shaft/153551523232 However the part is quite simple, so you can create one for your own shaft!

BOM for one wheel:
- 6x Inner roller
- 6x Outer roller
- 24x Ball bearings (623 - 3mmx10mmx4mm - InnerDiameter*OuterDiameter*Width)
- 1x WheelRimOuter
- 1x WheelRim (Optional, required only for the specified gearbox. For different gearboxes, you need to design your own piece!)
- 3mm carbon rods (6x12mm [11mm is ideal although theoretically incorrect], 6x35mm)
- 12x M3 screws (16-18mm for the given WheelRim part)

In order for the carbon axles to fit inside 623 bearings (3mm inner diameter), some sanding is required! Simply cut the required lengths with a metal saw, insert each axle into a drill chuck and use some sandpaper to achieve the required diameter! This process generates a huge amount of (possibly dangerous) carbon dirt, so wear a mask and be cautious! The shorter axles might need to be sanded a little bit shorter than 12mm as it is the whole length of the ideal cylindrical cutout (2x4mm bearing width plus 2x2mm blind-holes.) The minimum length is above 10mm, so 11 mm should be fine!

Supplied images depict a possible orientation for DLP printing the rollers and the centerpieces! Use a bearing pusher tool to insert the bearings into the rollers! The inner diameter of the bearing holes is set to 10.1mm that results in a tight fit for most cases by printing the parts on an AnyCubic Photon using 8x anti-aliasing (upgraded firmware). The depicted assembly is based on first generation parts. All the parts were fine-tuned for a more convenient assembly experience, thus the final product is a little bit different from the depicted ones!

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