QU-BD One-Up Y-axis spacers & clamp

Replaces the original Y-drive spacers and the (not received) belt clamp.

The main spacer is a revision from thing 212982, i'm too lazy to measure the thread pitch.
Also reduces the thickness, the original one was to thick so the belt was passing over one clamp hole.

Updated 23/02/2014: made plates thinner to fit the printing plate.
Updated 15/04/2014: got this changes since Feb... made shim and plate thinner to fit print plate