Motorized Yarn Ball Winder -STEP files included

A yarn ball winder assembled using 608 bearings, 8mm shafts and printed parts. Print without supports

I have mine printed and working but need to get all the print files properly named plus some details that will be required for assembly. Most of what is missing isn't strictly required for it to work, but I have some models for the case to hold the driver and pico. Also need to add in 8mm rod lengths, I will want to do measurements of my as-built setup rather than relying on the solid model.

STEP files now available, all are in "ballwinder-step-files.zip".

The motor hub presses into the gear it is a tapered hex, so only fits one way, similarly the lower swing arm is also a tapered hex.

The spindle is meant to print vertically, to reduce friction for pulling yarn off the spindle I included slim dovetail grooves to accept splines that are printed horizontally. This removes the friction from layer lines, you may not need these but I thought it a worthwhile addition. These are not tapered, and are a sliding fit, so need a drop of CA glue or the adhesive of your choice to keep them stuck in.

hardware required: assorted M3 fasteners, four 608 bearings two lengths of 8mm rod The spindle shaft should be approximately 175mm long, and no more than 200mm or it will stick out past the top of the spindle, and make it more difficult to push the yarn into the grooves at the top of the spindle to start the winding. The stationary shaft which the spin arm rotates on should be approximately 135mm long, and no less than 120mm if you wish to mount the assembly using the bottom protruding part of this shaft as the mounting point of the assembly- which I recommend.

The "spin arm" parts are assembled together using M3 (or #4-40) screws, the holes are sized so they'll self tap into the plastic.
The bearing retainer, motor hub and the shaft mount for the spin arm all use M3 hardware - captured nuts and M3 bolts, for the setscrews on the retainers all the M3 bolts I used were 8mm in length, longer will work in most places but a shorter one might be needed for the bearing retainer at the top of the spindle, it needs to fit in the bearing recess, so the whole thing can't exceed 11mm in radius. On my copy I used a press on shaft retaining washer not the printed part so I am not certain that my retainer part as designed will work here. The two bolts that self tap holding the swing arm together need to be 10mm max and 8mm will probably do fine here as well, 6mm would be bare minimum and I'd want to add adhesive between the two parts if going that short.
The big o-ring on the spindle I used was 110mm OD 100mm ID 5mm Width like these: https://www.amazon.ca/dp/B07GXFKGNT The exact size probably isn't needed a 4" (102mm) od one of similar width would probably stretch on just fine.

The motor I used is a Nema 17 ,the driver I used was a TB6600. The signal for the stepper driver I generated using a Raspberry pi pico in circuitpython, using the code I uploaded called ballwinder.py I connected a potentiometer to one of the analog inputs (A1) and a button to a GPIO input (GP0) pulse output is on GP16