Customizable spool holder for ender 3 (+-pro)

This spool holder lets you use the included plastic nut that came with my ender 3 pro. You can use it to get the diameter you want, so that it fits better for your spools. I am aware of some spools that are only 20 in diameter, and this should be perfect for them. I think the ender 3 has the same system, as well as.. probably most creality printers.. But I don't know for sure.

This part is a bit more simple than the included one that has a slight slope to make it easier to tighten the nut. This one is just hopefully tight enough and we'll rely on plastic being soft to keep it tight. I tested with PLA, maybe with PETG the deeply buried variable bottom_h will need to be a little less and topside_h more by the same amount. But it might also just work.

If you have a very narrow spool I would recommend turning off savings in order to get a more solid part. See the 20x60 file.

As for printing I recommend flipping the part by 90 degrees along the Y axis and making sure you have enoug