I’m no professional modeler or anything, but designed this today. Holds 12.5mm dia round magnets that were surplus from testing magnet fixtures. I usually have a lot of tools just jumbled on my desk and I have been asking for a magnet block for a while. Well - I decided enough waiting and made my own. Why the hell not, I’ve got tons of printers to use. 
I really need different, stronger magnets to use. These are still Neodymium high strength magnets, but they’re rings, so holding strength is a little weak. Which is exactly the reason we didn’t end up using them for the removable beds.

