I have built my own CNC router with 4X Stepperonline NEMA 23 (297 in-oz) motors and DM542T drivers, X, Y/A axis with 1605 ball screws, and Z axis with 1204 ball screw. I am using Arduino with CNC shield, GRBL 1.1 and Universal Gcode Sender.
All is working well, except for what acts like lost steps during acceleration. The problems seem to be related to jogging since the router makes engravings and parts quite well.
When I request 100 mm in X, I get something less, say 97 mm, depending on the value of acceleration. If I tap the X+ button 3X times quickly, the machine reaches full speed, decelerates and stops at 297 mm. If I tap the X+ button three times, waiting for the gantry to stop each time, the machine ends up at 294 mm. It loses 3 mm each time. All axis can be moved easily by hand, by rotating the ball screw.
It seems like an acceleration of 1 (mm/s/s) solves the problem but the system is so slow that this is not a solution. But I have no solution therefore. I am working with Stepperonline and they are talking to me but communication can be difficult and the exchange is slow and so far not very productive.
I am at a loss as to what to do next. I have removed the Z axis motor from the router and driven it “no load” with the same results. Request 4 mm (one full rotation) and I get a few degrees less than 360. Also, if I request 0.2 mm, the motor clicks but does not move.