[closed] FreeCAD path, strange movement in Z axis

It's odd that your limits are different for joint and axis, if this is a cartesian machine. But it isn't likely to be the problem.

Your acceleration is already rather low. Acceleration of 10/s * velocity is more common.

So, try reducing the max velocity instead.

Also, listen very carefully. Can you hear the Z axis stall?

Can you definitely jog down to -0.1?

It was the G43 command.

Somehow there is something wrong there. Maybe it is one of the gmoccapy settings.

Thanks for all your help, it was quitte an experience.




forum.linuxcnc.org/41-guis/29398-semi-ma...es-in-gmoccapy#60521

Please note, that gmoccapy takes care of its own to update the offsets,
sending an G43 after any tool change, but not in auto mode!

wiki.linuxcnc.org/cgi-bin/wiki.pl?Gmoccapy

That doesn't make sense.

If you have a G43 between the two Z moves, and the tool length in the table is exactly the right value, then you might see no Z movement.

But if there is a G43 and _then_ two Z moves, the Z should move.

andypugh wrote: That doesn't make sense.

If you have a G43 between the two Z moves, and the tool length in the table is exactly the right value, then you might see no Z movement.

But if there is a G43 and _then_ two Z moves, the Z should move.

The G43 was early on in the program, before the G1 moves.

I removed the G43 from the program and everything works as expected.
Will try to find out what is going wrong. But it does like G43 is the guilty command here. The z-axis would move in LinuxCNC's idea but it was just the offset that was stored in G43 (and that kinda works out with the numbers, G43 offset was 21.43 mm and that was about the amount of space that the bit was positioned above the spoilboard). The tool gets measured with a toolheight sensor every time I run the program and gmoccapy stores the offset in the LinuxCNC tooltable.

Break the problem into pieces without red herrings? So running the above code stops the tool 6mm above G54 Z0 ?
But rerunning with the brackets on the 2nd last line doesn't stop the tool at -0.1mm ?
ooops meant to say without the brackets

jbraun wrote: Break the problem into pieces without red herrings?

Code:

G17 G54 G40 G49 G80 G90 G21 G54 M5 M6 T1 G43 H1 M3 S8123 G0 Z6.000 (G01 Z-0.1 F900) M02

So running the above code stops the tool 6mm above G54 Z0 ?
But rerunning with the brackets on the 2nd last line doesn't stop the tool at -0.1mm ?

Exactly, that is what is happening.
=====> Z physicaly goes to 4 as it should
Z should now be physically -0.1 and under the surface of the spoilboard, but it is still physically 4 as was set by the G0 command. The DRO changed though, it displays now -0.1

As I said before, when I remove the G43 command all works as expected.