When building and rebuilding models to dial-in a design, I find myself frequently relocating the exact location of the electronics modules.  Since these are never structural in nature, they don’t really need to be bolted in place, so I used push-rivets for a while.  Those left the modules rattling around a bit much for my taste.

Then I found these handy cup magnets.  They have an 8-32 threaded stud that fits standard VEX fasteners, and they have an extremely strong grip.  These magnets are easily strong enough for light structural work too, if needed.

I now keep one full set of electronics fitted out with these magnets for prototyping, and to bring older models back to life.

You can find them at Amazing Magnets.  I’ve used the CUPM625 size, which cost about a (US) dollar each.  The larger CUPM750 size will work with VEX too.

See also: Related VexForum thread