The design uses 1 (one) 3mm x 2mm magnet, and 38 (thirty eight) 8mm x 2mm magnets. The magnets don't have to be incredibly strong, I did not use N52 magnets but it wouldn't hurt if you choose to upgrade the magnet selection. I purchased a cheap magnet kit off amazon, and have many magnets left over.
Assembly is easy, but may require light taps with a hammer to set the magnets correctly. All the magnets are oriented the same way! I chose north-up. This includes all the magnets in the pen as well.
Print files are available on MakerWorld, and coming to Thangs soon!
MakerWorld: https://makerworld.com/en/models/745159