Strange tool paths

Dear all,

I'm a bit uncertain where to place this question as I'm puzzled where my issue comes from...

I have managed to setup a basic 3-axis machine just for learing the trade with a RPI talking to a Mesa 7i76e with open-loop steppers. The machine is basically running and ran several examples, that's how far I am. Mastering the CAM side seems to be the issue...

Whenever I load some self-generated NGC files I see some strange tool paths way up in the air and outside the machine's limits - see attached screenshot, that thing in the red circle. The strange thing is that this happened with two different CAM setups: First I tried a stone-old Catia V5R18 CAM to which I have very limited access through my old university CAD pool but that was just because I was used to this 15 years ago during a project. I've used the FANUC-PP which comes with Catia, btw. I then switched to Fusion 360 which I intend to use for the moment - however the same thing happened (the screenshot actually shows the F360 example). As I initially exported the CATPart and imported it into F360 via STEP I suspected some issue there - however the same issue happened when I created native geometry in F360. I've double checked the *.ngc files with NC corrector and there at least the F360 code looks spot-on.

I'm a bit lost as where to search for the root cause to be honest. As it happends with both CAM systems I'm tempted to think that I did something wrong in the LinuxCNC config but that should also show in the examples, shouldn't it?

Maybe somebody can shed some light on this.... 

EDIT: I've added the F360 file now. I can't even find a Z=450 reference in there. Sorry, but I'm completely lost.... 

Best regards,


Tim




 

Hi,

you're right, the screenshot is 1003.ngc and the file is 1004.ngc but they both show this strange runaway behaviour which puzzles me. Regardless of what I'm doing in both Catia and Fusion 360, as soon as I load the NGC file in LinuxCNC this motion up to this Z=450 limit is there and I have absolutely no idea where it could come from.

If I understand it correctly you had a look at the 1004.ngc? Do you see this runaway path?

I'm not using remaps - at least not that I'm aware of but obviously I'm still in the very steep section of the learing curve....

Best regards,

Tim

Hi JT,

the strange line is highlighted in the screenshot, it appears as it is always the same one "N85..." regardless of the actual geometry. I've created five test files so far and it always highlights this line (however the arguments in the line aren't always the same). I've bodged e.g. some pad with a pocket in Fusion 360 CAD and ran it through the CAM, that's the 1004.ngc IIRC. The files are as the linuxcnc-PP which comes with F360 creates them.

Best regards,

Tim

Dear all,
I think I found my f'up - this "strange" path" is related to the tool change. I ham-fistedly removed M6 from one of the ngc files - the offending bit is gone and the machine is running the code just fine. So I guess it's simply a rogue tool change position which I accidentally defined at some stage. Mastering the tool change stuff and implementing the TLS is anyway next on the list.

So it turns out to be another PEBKAC issue, sorry for that. 

EDIT: A litle more explanation what happened, it was entirely my stupidity.... Some weeks ago I started looking into the tool change subject and followed Talla83's instruction video - and stopped half-way through, I only manage to work on the machine occasionally. So yes, M6 was already remapped to a macro and the INI was already changed accordingly - and over the weeks I completely forgot that I already did that stuff. And off course I didn't correct the tool change position in the macro. So getting that stuff to run properly will solve the other "issue" along the way ....    ( is there a facepalm emoji? I think I'll need it from time to time).