I am trying to do 2 sided milling and I drilled out 4 holes in the spoil board and then 4 holes in the stock to use with alignment pins. The problem is the holes along the x axis are not where they should be. They are off center. It's only along the X Axis as far as I can tell. Here is a picture of what is happening as best as I understand it. I can post pics of the stock with a ruler tomorrow if need be. As you can see by the image the more you go from the center line the more the center points of the holes are shifted off center. And it seems to be mirrored Seen that happen before? Also Fusion 360 file here if you think you want to look at it.
How about the calculate in the GRBL settings? I looked and Steps were all set to $100=199.100 ;X-axis steps per millimeter $101=199.100 ;Y-axis steps per millimeter $102=199.100 ;Z-axis steps per millimeter Setting it to Lead Screw Driven and 1/8 micro step type changes it to 200.000 The motors im using are the Open Builds NEMA 23s. Why is default set to 199.100? And shouldn't I be using 200.000? Thanks for helping.
You actually need to calibrate it to what your screws are. There may be slight differences in the screws depending on batches. All CNC machines need to be calibrated. If you are using OpenBuilds Control, there is a Calibration Wizard with instructions. If not, I posted a simple 2 minute-ish video below on how I did mine with the necessary math. OpenBuilds suggests 199.1, because they tested them and that is probably and average that is the suggested starting point. That being said, On my lathe my steps/mm are 198.XX (I cant remember the XX of the top of my head).
