Root 3 CNC - Test Pieces

A test piece was designed in Fusion 360 to do the initial testing and calibration on the machine.  It is a 10cm circle next to a 10cm square.  The circle has a center bore, and the square has a slot, with the two pieces connected with a small bridge.

The first test-run started well, but finished quite poorly, as the spindle went of course on the last run of the toolpath:



I thought maybe the feed rate was too high, so slowed it down and added a few more passes to the depth.  This actually made things worse:



The X-Axis belt was tightened.  While examining the machine after the 2nd run, it was noticed that the Y2 motor was not warm.  After investigation, a wire was found that had come loose, meaning the Y1 motor was pushing the entire spindle assembly from one side only.  The wire was tightened, and the test piece run two more times:







By the 4th print, things are looking a lot better (sure helps using both Y motors).  Measuring the X and Y dimensions, the test piece is off between 0.5 and 1.0mm.  This information will need to be included into the X+Y step calculations in order to get the CNC cutting more accurately.