Hi, I’ve been running into random glitches/feed-stops when cutting, flagged as GRBL error 26 or 36 around line 1790. What’s especially strange is I don’t see the lines showing up in the console within the .nc file. I should note that the attached screenshot is from after trying to resume from line (after the issue first occurred).
I’ve also noticed some errant moves that are not showing up in simulation, could there be something messing with the communication between my laptop and the controller?
CAM: Fusion 360 (post from Neil Ferreri)
Machine: Shapeoko 4
Software: Gsender 1.4.12
Hm, I had gotten this USB-B to USB-C cable from Tripp Lite specifically for this machine so I wouldn’t need an adapter to my MacBook (and thus cut down a potential point of failure), but let me try again with the original cable. Are there any others you might recommend?
Can you tell me more about how to use the $C check mode?
One suggestion for your post, output another decimal point or two. Way back in the day we had GRBL throw occasional errors that we traced back to arc endpoint mismatches. There can be mathematical errors due to rounding that exceed GRBL’s margin of error when you use so few decimal places. Could be one reason for some of these issues. The default Carbide post should output at least 4 I believe. 5 is better.
Grbl is pretty good about calling errors what they are, and we’d typically see the arc endpoint error called out specifically. He’s also using mm, so those rounding errors usually aren’t relevant.
gSender has a button for it. I’m not by a computer now, but I can send you a screenshot later. You can also send $C through the console. When in check mode, the gcode will stream to your controller, bit the machine won’t do anything. It’s a good way to see if the issue actually lies in the gcode.
If everything passes in check mode and your USB cable is a good one and you’ve restarted the computer and everything and you’ve tried a different post processor, you might be looking at a an EMI issue. I’ve seen these issues across forums and it’s usually just a USB communication issue that can be as simple as a restart, disconnect and reconnect, or new cable.
I had a similar issue on an inch model, Rob had suggested switching to metric and that resolved the issue. It was a series of arcs that was the problem area.
How can I tweak the output decimal places in the fusion360 post?
This portion of the cuts is a ball end mill scalloping pass, I wonder also if fusion 360 smoothing might help or hurt.
I do lean towards this being a communication error given other random glitches midway through cuts, I just really don’t look forward to hunting electrical gremlins.
Hm, since this error:26 appears in check mode whenever I try to “run from line,” regardless of what line I choose, I’m inclined to believe it’s actually due to the “run from line” feature in gSender. I don’t get this error if I just run from start.
That being said, I still don’t have a good explanation for the random halts and errant moves, I’m going to try physically separating my wires more and grounding my vacuum hose to the machine ground if that doesn’t work.
