XRP Chassis for Mecanum Wheels Robot

In addition to creating a CAD based .step file for others to expand upon this robot was designed to support existing XRP accessories/kits and has been optimized for easy printing. One impactful change is the improved channel around the perimeter of the chassis which has been adjusted to remove steep overhangs from fillets. Avoiding long bridges has removed the need for support which results in a quicker print without any waste. Handles have been added to the sides for convenience while also creating a stronger internal structure. There are some adjustments to the precision of the motor brackets and other minor enhancements as well. While it is inconvenient to toggle the power switch, the scale was dictated so the chassis would fit on a standard Prusa printer bed to improve accessibility.

Recommended Print Settings

• 1.2mm+ wall thickness
• 25%+ infill
• 45 degree fill angle
• 120 degree bridging angle

Fill and bridging angles are specified to print the bottom text and channel overhangs cleanly. A 45/135 degree bridging angle will droop in the ‘X’. The recommended settings are pictured below.

Control Software

This Mecanum Wheels Robot can be easily controlled with PestoLink from AlfredoSystems. Once PestoLink has connected to the XRP a gamepad can be used to control the bot. 

After following the installation instructions for PestoLink-MicroPython find pestolink_mecanum.py in the print files to control this bot.

• https://github.com/AlfredoSystems/PestoLink-MicroPython
• https://pestol.ink/

Required Parts

• XRP Controller Board (https://www.sparkfun.com/products/22727)
• Hobby Motor - Plastic (https://www.sparkfun.com/products/24053)
• Mecanum Wheels (https://www.amazon.com/gp/product/B08VGK7LWZ)
• Battery Holder with Barrel Connector (https://www.sparkfun.com/products/9835)

Attribution

This Mecanum Wheels Robot is a ground-up rework of the bot created by Travis Foss found below. As of now I would recommend following the code in the tutorial if you are unfamiliar with how to write it yourself. Travis, thanks for sharing your project, it was a great inspiration!

https://www.digikey.com/en/maker/tutorials/2024/enhancing-xrp-functionality-with-a-mecanum-wheel-design