Crab magnet

This may end up being more of a proof-of-concept than a usable design, because I have no idea how one might find the same size of magnet I used here. I had a bunch of tiny round furniture magnets that measured about 5.5mm x 3mm, and based my model off those measurements. I've included the blank model (with a solid base, but no hole) in case you want to customize it for your own magnets. Normally I would have used OpenSCAD to add the hole, but in this case I found it was less of a hassle to use Blender.

Make the radius of the magnet hole 0.2mm wider than the measured magnet radius (i.e. the hole is 0.4mm wider in diameter). The magnet should be a very tight fit.