I noticed that some simple parts were dimensionally inaccurate, so I tried using a digital dial indicator to fine tune my steps per mm. They were definitely out, as I was travelling more than the commanded distance even over small distances like 5mm. The odd thing is, I can either adjust the steps/mm to make small distances accurate, or larger distances accurate, but not both. I typically travel 25mm in 5mm increments and record the actual travel at each increment. I settled on 198.6 steps/mm because the 5 and 10mm increments are spot on, and the 20 and 25mm ones are close enough (25 actually travels 25.12, but it’s better than the 25.25 that it was originally travelling). The odd thing is, the 15mm increment ends up being less than 15mm travelled even though all the rest are on par or above. I can’t think of how this is possible nevermind how to remedy it. To be clear, all my readings are repeatable, and when I travel back to zero, it’s spot on.
My setup:
-Nomad pro with carbide motion 2.4e board
-cncjs
-nearly all backlash has been preloaded out of the antibacklash nuts
-using a SMW tool plate and mod vice to clamp my dial indicator base, which is rock solid
-I have made reasonable efforts to reduce any parallax error, which shouldn’t be a concern anyway because it should affect the readings predictably.
Any input on this would really help. If I need to provide more info or try something, please chime in.
Jeremy