Releasing a design I developed and built for a 3D printed beltbox. Intended use is to replace a NEO/Falcon with a 775 as the steering motor on the Swerve Drive Specialties Mk2 module for BOM reasons by leveraging BOM exempt speed controllers (Talon SRX/Victor SPX) while maintaining near zero backlash in the steering powetrain, but it’s got uses beyond that.
Reduction is 12:36 with a 41T GT3 3mm belt, which gives a free speed around 6000 RPM, in the same range as a NEO or Falcon. 36T pulley is 3D printed on Markforged, along with the housing. Final weight is 1.13 lbs without the speed controller, and using a stock AndyMark DeCIMate shaft. Weight (and cost) can be reduced by making the shaft custom from 3/8" Aluminum Hex.
Photos of CAD and assembled beltbox: https://photos.app.goo.gl/pqAf7XVaZNyupBkp6
Link to Onshape CAD: https://cad.onshape.com/documents/b9c1cb73bae15ebc932e1285/w/5f321242ad63b836fe3e30d2/e/5576a158caa446abb9f119d5
Assuming a 775 from FIRST Choice and an exempt speed controller, the BOM cost of the unit to replace a Falcon or NEO+SparkMax comes out to $35 including the 775Connect. If using a custom aluminum output shaft, that drops to $22.