QU-BD One Up and Two Up Z-Bearing Alignment Spacer Upgrade

This spacer will upgrade the QU-BD One Up and Two Up printer so that the distance between the threaded Z-screw and the smooth Z-rod are at the correct distance from each other, and better constrain the linear bearings to reduce the sagging of the gantry.

Installing this upgrade will reduce or eliminate the Z-banding caused by the binding of the vertical motion of the gantry due to binding of the Z-screw and the nut.

By stiffening the alignment of the linear bearings to the gantry, this upg