Repurpose Press Fit Pulley Motors for 8MM Shaft or 20T Pulley by SurgeFF

Last crawled date: 3 years ago

Update 2-18-21: Motor Shims didnt have holes in them so files have changed to 2mm shim and 4mm shim.
Update 2-17-21: GT2 belt version was just a bit too loose. New version uploaded.
Update 2-17-21 : Uploaded a version for a installed GT2 belt for the outer ring. When I mean installed, I mean glued. But its better than iffy print quality for gears and the material should dampen the sound a bit.
Update 2-16-21: Found out some of the files are kinda wonky so Im pulling all the old files and reuploading new ones that will print as intended. Some files are the same part, but for ease of choosing I named them appropriately. If you find the file comes out weird or whatnot, then I probably already took it down and replaced it with a functional version.
A very prototype repurpose/recycle old Nema17 motors with press fit pulleys on them. This will add some length on the motor body; but the carrier is designed to allow a custom 20T pulley to be added at a desired length, or you can manually drill or CAD cut a 8MM hole to secure a screw. The shaft is 12mm thick so no problems on durability for most materials. Once I get done testing Ill upload more instructions and whatnot.
Assembly: Still getting the flaws out to make this as easy as possible. So after tweaking, start at the motor and install each part moving upwards.
1) Shim if needed
2) Gearbox housing lower
3) Fit gears(use medium to heavy weight grease or lube)
4) Lower/fit gearbox housing top
5) Fit Carrier
6) Screw in carrier retainer and whole assembly with M3 screws.
E-steps you need to multiply your current steps by 4. Turn down acceleration to NO MORE than 17% of what it was. This applies to standard Nema17 motors and a 8-bit controller. If you have better hardware, then you can experiment further. You have been warned. Currently mostly tuned in except for compensating for resonance frequencies are:
[Ender 3 Pro]
400 Axis steps per mm
3000-3400 Max Feedrate mm/min(If you havent changed much in Marlin and have a stock board)
100 mm per second Max Acceleration
0.4 mm per second Jerk
{I might be missing one but here are files used for reference.}https://grabcad.com/library/pulleys-gt2-20t-set-1
A video of it in action under its own steam. Testing going well.https://youtu.be/8Sn-LYkH3vo