Download the Spool Rotator

You can download the Spool Rotator here:

But, what do you really need? There are lots of models.

At a minimum you need:

  • SpoolPullyFlange or SpoolPullyFlange-Small
  • TopNutHolder
  • SpoolFlange
  • PullyGear
  • CMPG (Circular Magnetic Pinion Gear)
  • SpoolHangerBlock
  • HangerArm x2 (you need two hanger arms)

The other parts are all optional, but you might find you need some of them. They allow you to use different sized pulleys on top or bottom, and to fit spools with different sized hub holes.

To use pulleys you’ll need the base version of the upper and lower pulley parts:

  • PullyGearBase (top pulley)
  • SpoolPullyFlange-Base (bottom pulley)

You might also find that an adjustable filament guide is useful too.


You can print any of the pulleys you think will be useful. The smallest ones are interchangeable between the top and bottom. The largest one that fits on top is the 50mm pulley. The 60mm and larger pulleys only fit on the bottom. They just push on and pull off using the bearing as a connector.

The upper magnetic gear base connected to a 40mm pulley.
The pulley flange base is connected to a 60mm pulley. The smallest pulleys are printed with their flanges.
Both bases accept 2/7ths of a bearing. 2mm protrudes. The pulley plates are 1.7mm thick and fit snugly over the bearing.

Spool Flange Sleeves

There is no standard for the size of the hole in the hub of a spool. I originally designed the spool rotator for a 55mm hub hole, but many of the tricolor filaments have larger spool hub holes.

So, I developed a set of sleeves that fit over the original 55mm spool pulley flange and spool flange. These fit snugly and effectively increase the diameter by 2 or more mm in 1mm increments up to an additional 15mm in diameter. That extends the range from 55 up to 70mm. You use them in pairs.

The various Spool Sleeves are rated for how many mm they add above 55mm. So, if you measure a gap of 2mm at all points around the 55mm spool flange, you could add the 3mm spool sleeve and it should fit just snugly.

You don’t need to print them all! But, you could either print the ones you need in pairs that are the same size, or you could choose adjacent sizes to cover more possibilities. Only the pulley side of the spool needs to fit snugly, the other side could be loose and slip.

Plastic spools sometimes slip on the plastic flanges or sleeves. You can increase friction a few ways:

  • Put some rubber cement on the sleeve and let it dry.
  • Put a thin layer of electrical tape around the outside of the sleeves or the pulley flange bases. It doesn’t need to go all the way around to work.
  • Cut off the sticky part of a sticky note and attach it to the outside of a sleeve or flange base. It doesn’t need to go all the way around to work.

Size Range for Spool Sleeves

The nominal sizes each actually cover a range of spool hub sizes of about 1.5mm to 2mm. So, more than one of the sleeves might work for your spool, although one might not be fully seated (but would still work). You use them in pairs.

Spool Sleeve SizeMinimum Spool DiameterMaximum Spool Diameter
no sleeve5355
Spool Hub Hole Sizes for each Sleeve Size

Filament Guide

The adjustable filament guide is described on the Assembly page. You can download it here:

The tube-type filament guide isolates the spool from the force of the filament swinging around as the extruder moves.