Universal (parametric) and easy to spin spool holder

thingiverse

Changed printer frame recently and my old preferred spool holder no longer fit. Tried many of the community provided but all of them had some drawbacks. Either they took a long time to swap the spool like with the conical ones or simply provided too much resistance when dispensing filament which can lead to printing issues and artifacts. So I designed this super simple spool holder. Idea is to put ball bearings on printed elements, add ending element and just screw everything in place. Plastic part remains static and only thing that spins is spool and bearings. This provides super easy spinning and is very easy to construct and print. For bearings you can use anything you have or can get easily and cheaply. Considering for which forces bearings are usually rated 1kg spools are not even a factor so getting used up ones is a valid strategy. Bearings you can see in my photo are some 30 years old I got from my father and cleaned up a bit. While source file is SCAD it does rely on [BOSL](https://github.com/revarbat/BOSL/) OpenSCAD library. Check their GitHub for installation instructions. It's very easy to install and offers a lot of functionality OpenSCAD doesn't have built in. To configure this model you need to measure total length of the part. This length is between holders and doesn't include nuts and frame itself. So just the empty space. After that measure bearings. You will need outer diameter, inner diameter, width and outer wall thickness. Once that is done, enter number of bearings you have and you will get fully prepared STL for printing, including total number of elements. **Please note:** Inner diameter should be entered exactly. Model has octagonal elements where bearings should go because it was designed to be friction fit. Exported STL is configured for my own use and you can get bearing dimensions from the SCAD file.