Gauge block holder

This is a simple squareness reference made by using a 4" gauge block.

If you own a gauge block set you know the squareness of a block is not guaranteed. But for squaring up the axis of a 3d printer my blocks are way better than what is needed.

The holder simply secures the 4" gauge block to the linear guide rail bearing block. You then run a dial gauge up and down the 4" face by using the printer's Z axis. Adjusting the axis tilt until the reading is constant. Next, rotate the dial indica