Spool Core ID Tester

Have you ever ripped apart a cardboard spool being convinced you can load the spool core onto a Bambulab Reusable Spool, only to realize the cardboard spool core inner diameter is too small or too wide to fit properly?

Well, these two are fast, print-in-place models you can use to verify the spool core size before ripping the cardboard shoulders apart!

The one marked with 80mm is the expected spool core diameter compatible with the Bambulab refillable spools. If it happens your spool has a 75mm core inner diameter then you want to measure the core width:

• if it's 57mm (62mm with the shoulders) then you use my eSun Refillable Spool
• otherwise you can either search for anything you find appropriate, including the customizable spool

Feel free to comment if you need additional testers.

Usage is pretty straightforward, insert the tester partially closed inside the center of the spool and let it open on the opposite side:

• if the tester opens up completely then the spool core corresponds to the indicated size
• if the spool core is smaller, the tester will not be able to open up completely
• if the completely open tester can move side to side while inside the spool core, then the size is greater than the indicated size

I hope this simple print helps to prevent fellow users from ending up with a destroyed cardboard spool without a way to properly secure the filament, as it happened to me.