Automatic Filament Guide & Removable Bearing Plate for Tomik Respooler (GT2, dual bearing)

This is an accessory I designed for my filament winder, based on Tomik s Cuprou's "Fast Strong Automatic Respooler" - specifically V1, since this project started before V2 came out (link to his page, files not included - download them from there). If you already printed V1 and don't want to reprint everything to switch to V2, this accessory fits right on it. I haven't touched or modified the original part: I only measured where the two pins sit and built these three groups around them.

PART 0 - The double-helix screw

V1 of the Tomik only has a manual rod you push by hand to guide the filament left and right. This screw replaces it: it turns in one direction only, and a pawl follows the diamond-shaped groove so the filament guide moves left and right automatically, no need to reverse the motor. Runs on 2x 608 bearings. Fit a small soft spring between the cap and the back of the filament guide, to keep it pressed into the groove - I used one of those very light springs from a wick-style diffuser/nebulizer stopper. I'd recommend printing this whole part in PETG: it's small and constantly under load and friction, so it holds up better than PLA. This part is based on the "Level Winder (Diamond Screw)" by chuyskywalker (link), released into the public domain - thank you for the great work.

PART 1 - The drive group

This is the belt-and-tensioner setup that turns the screw from the spool's motor: the one that keeps the filament guide moving automatically while the spool winds.

There are two ways to set it up, pick whichever you prefer:

• Large 137-tooth pulley plus GT2 436mm belt, if you already have that belt at home. Works well, I tested it myself first.

• Large 141-tooth pulley plus GT2 440mm belt, this is the size it was designed for: every spool turn winds the filament right up against the previous one, like bricks in a row. If you buy the right belt, it's the best choice.

PART 2 - The removable plate

This is the plate that clips onto the winder frame's two existing pins and holds them straight with a bearing on each side, instead of just one support point. It also includes the adapters: one to connect a motor (N20, JGA25 or JGA37) to the pin, and one to turn the spool by hand with a drill.

What you'll need (not printed)

• 2x 608 bearings, for the screw - here's the ones I used: https://it.aliexpress.com/item/1005011757424969.html

• - 2x 6800ZZ bearings (10x19x5mm), for the plate - here's the ones I used: https://it.aliexpress.com/item/1005008685183855.html

• - 1x small soft spring, like the ones in wick-style diffuser/nebulizer stoppers

• - M3 heat-set inserts + M3 screws, for the 3 spacers

• - 2x M3x8 bolts, for the screw

• - GT2 6mm belt, 436mm or 440mm - same seller has both lengths as an option: https://it.aliexpress.com/item/1005002784439262.html

Materials

I printed and tested everything myself: the drive group parts in PLA on my Anycubic Kobra X, then the final versions in PETG on my Bambu Lab A1 mini. If you print your own, I'd recommend PETG for the plate and adapters: they flex and get pressed every time you take them apart, and PETG holds up better over time.

How to fit and remove it

The plate isn't screwed to the frame: it clips on and comes off by hand, no tools needed, a bit like a box lid. Flexible tabs hold the pulleys in place on one side, a raised rim locks them on the other. Handy if you need to access the spool or take everything apart to store it.

Thanks to Tomik s Cuprou for the original respooler design, and to chuyskywalker for the Diamond Screw mechanism.

I'm still fairly new to 3D design, so I've also made the editable source files available, not just the STLs: if you find a better way to do something, feel free to modify it and share your variant in the comments, I'd love to see it!