Stepper motor thud/stutter when using M10/M11

[pietro.odaglia]

Hi everyone,I’m facing the following issue:
my machine has a clear “thud” or “hick-up” when M10/M11 commands are issued.
- the motion is along only one axis, X
- the X axis has a slaved motor (gantry), slaved through SW (Mach3)
- the Gantry runs smoothly up to 15’000 mm/min (ballscrew limit)
- whenever an M10/M11 command is issued, I can hear a clear, single thud (almost as it hit something)
- happens at all speeds I checked (from 1000 to 15000 mm/min)
- many times the two motors go out of sync and the gantry gets stuck

One way to solve it would be to remove M10/M11 and replace them with “normal” macros (stopping the motion every time an output needs to change state), but I would still like to know if you have any idea about how to solve it.

The configuration is the following:
- uc300-eth
- leadshine EM705
- stepper motor, 2Nm
- PSU 20A@48V
- Mach3

If needed, I can post the part of the code causing the problem.
Any help or hint would be really appreciated
Pietro

[ger21]

I was incorrect, so deleted.

[cncdrive]

No, it should not stop the motion, I mean the M10/11 is working without stop in mach3, however the timing is not as precise as in the UCCNC, but it does not stop the motion.
If it stops the motion in your system then it might be a bug in your mach3 version. I would try to install a different version.

You can also post your profile file and tell the Mach3 version number to let us check.

[pietro.odaglia]

So, I found the culprit:
nothing to do with M10/M11, was rather the combination of series of X moves (see code below) and my CV settings (CV distance tolerance = 1.5). Got rid of the CV dist and everything's smooth now.

G00 G90 G17 G54 G40 G49 G80
...
G28.1 X 2
G01 F4500.00 X131.00
M11P3
G01 F4500.00 X181.00
M10P4
G01 F4500.00 X339.00
M11P4
G01 F4500.00 X341.00
M10P3
G01 F4500.00 X339.00
M11P2
G01 F1250.00 X231.00
G01 F1250.00 X15
M10P2
G01 F1250.00 X5
G28.1 X 5
...

Thanks for your replies.

Pietro