Nothing much else to add. I've included a step file for anyone who wants to make it a more snug fit, since I went through way too many prototypes and decided this was good enough (I don't have calipers, don't judge me). Printed on a Bambulab A1 with 3 walls, arachne walls, 15% gyroid infill. Magnets are optional, although don't use anything too powerful. The base is too thick for n35 grade magnets to do anything, but anything more powerful might interact with the spring and cause the trainer to not function properly