Spool-Lock Easy Filament Clip

When it comes to filament clips there are hundreds of designs out there but most of them are either tricky to use, often making you wish you had a third hand, or they clip onto the side of the spool which is much simpler, but can easily be knocked loose, especially on a filament rack.

The Spool-Lock design is easy to apply and latches itself on to sides of the spool at just about any point on the spool.  Just feed the loose filament end through the clip and then press or pull the clip down so the pins engage the holes of the spool and lock in place.  To remove the clip simply squeeze the tabs and the clip will release.  This design even works with cardboard spools, where multiple small pins press into the cardboard to hold securely in place.  Each variant for the different spools is labeled so you won't confuse them, though I recommend also selecting a different color for each type if like me you have multiple types of filament spools lying around.

At present I have designed clips for plastic spools from Bambu Lab and Sunlu, as well as for most cardboard spools.  The cardboard spool clip comes in 4 sizes from 56mm-62mm.  The 58mm worked best for most of my spools, but measure the inside width of your spools to see which version works best for you.  Let me know if you need other sizes or what other spools I should design for.    

Note: Because tolerances can vary between different printers and different filaments, it may sometimes be difficult to feed the filament through at first.  If this is the case, try twisting the clip as you go and slide the clip along the filament a few times to help smooth out the opening.  If that doesn't work, try adjusting the X-Y hole compensation in the slicer settings.  I recommend starting with 0.1 or 0.2 mm, this may be necessary if you print in filaments more prone to shrinkage such as ASA, ABS, or possibly even PETG. 

UPDATE: Jan 2026 -All models updated to improve print-ability, in addition, the Bambu Profile now includes a slightly larger clip that is useful for some over-filled spools, particularly engineering filaments like ABS/ASA that sometimes stretch out the spool when full.  Also added a model for SUNLU Gen3 spools, so you will now see 2 variants in the SUNLU profile.  Most newer SUNLU spools are Gen3, but there are still Gen2 spools being shipped as well.  Gen3 spools are very similar to Bambu spools in dimension and the Bambu clips will probably also work with them