I am currently seeing something similar?
I think I have the X7 fairly well tuned, and in the cut sizes I've been doing (usually ~300x300mm), I haven't seen any huge problems.
Well this last week I've had to run a big job that takes up the full 1200x900 table.
Well I'm seeing a completely repetitive drift of approximately 1-2mm across the table. So... if the job starts half the cutting of a vector graphic on one side, jumps to another feature and wanders around table before coming back, it'll be 1-2mm off.
This offset is 100% consistent between jobs.
Also, if I make a test mark after homing the laser, run the job, and make another test mark, the marks are a mm or so off from the original mark. If I repeat homing, test firing, running the job and firing again, both marks are in exactly the same place as the first set. If I don't home and run the job again, then test mark, the new mark is offset by exactly the same amount as the first offset.
I tried running with the laser and air off during the cut and the offset still occurs so it would seem that its not noise from the laser or wiring.
I've measured table backlash and its nearly immeasurable, and to my untrained eye, it looks like the floating point is being truncated, but I'm hoping its just my settings.
I have approximately 6.3um/step and have the settings on falling edge.
The table is the LO 1200x900 kit (http://www.lightobject.com/XLE-1200900- ... -P737.aspx)
The motors are the 3-phase ones that came with the table
The drivers are the LO 3MD560 kit (http://www.lightobject.com/3MD560-Leads ... -P836.aspx)
And I'm running the LO-X7 DSP.
Max speed set at 600mm/s on X and 400mm/s on Y (not sure about X7's pulse rate, but the 608 you said was 150kHz so at 6.3um, the max theoretical should be 945mm/s?)
I have Max_Acc at 10000 on X and 3000 on Y. Start is 15 (no idea what this parameter means so I left it at default)
So my questions are:
- What is the right setting for Pulse Edge for the 3MD560 (I can't find documentation on the LO version)
- What do you recommend for microstep settings for the 3MD560 and the Um/pulse setting (the microsteps silkscreened on the driver looks wrong for 3-phase steppers)
Any ideas or suggestions would be helpful as I'm currently cutting in a tiny area to work around it as seen below.
