msm and fusion 360 g18 problem

[neptunier2]

hello,
i just switched to fusion 360 and after long checking i found out that msm seems to not support the following line in the gcode: G18 G3 X134.732 Z0. I-2.5 K0.

in the standard screen and other screens it works. is there something i could do about it? attached is the whole gcode file.

thanks, michael

[DaveCVI]

Hi,
So it looking to me like Fusion 360 has generated a gocde line which mach does not care for...

That line in the file results in this error message from mach:
Radius to end of arc differs from radius to start , Block = G18 G3 X134.732 Z0. I-2.5 K0.
Line 19

I also loaded mach with the stock 1024 screens and an attempt to run that gcode file results in the same error message.

That confirms that this is not an MSM specific issue, which makes sense to me since all gcode interpretation is done by Mach and MSM has no involvement in parsing or executing gcode (there are not any script interfaces to that level of mach for MSM to call).

You'd have to do the math to see if the X,Z vectors Fusion generated are correct for the anticipated arc move. I will observe that this is a G18 plane (X,Z) - and I suspect that does not get used in mach code very much. If the XZ vectors are correct (math wise), I would not be too surprised to learn there could be a G18 interpreter bug in mach. Alas, if that is the case, we are out of luck as Art Soft has refused to even accept mach3 bug reports for several years now.
Dave

[neptunier2]

thanks dave, i was trying out more using the generic mach3 post which i did not change and msm accepted that one. there it used the radius instead of i and j.

after more playing arround it seems to work now. the g17 and g18 are lead in ramps, so it is correct with their planes.

michael