that's clever. so normal flat rare earth magnets on the base of the carriege and normal non-magnetic ball bearings on the top.
Very neat !
I think the ones I've seen have been spherical magnets - which obviousuly would cost more.

I like that balloon - so how do you do the change filament thing - via the printers control panel or through simplify3d ?
Something i've never done.

Saw those cable clips. Looked quite good.

I wonder if part of the size issue is that those things are designed for abs. I only ever design for pla, and dimensions are either pretty close or slightly smaller than I designed. As these are generally too large - could simply be that they've already factored in the abs shrinkage.