Basic Printable Spool Holder Top Piece

Thank you to JadeKnight for creating the original one. http://www.thingiverse.com/thing:3066

I have modified the top piece slightly to accept the MakerBot Z rod, as I had four of them lying around after my ACME Z-roid upgrade (got them off flea-bay, and the seller is truly excellent).

There are two versions, and I think I will be using one of each. On the original one I can thread the Z-rod in there, while the other version will let the Z-rod slide freely. This should make changing the