Plunge Error on Job Start

Ok weird one. Went to cut a test inlay project with one of our company’s engineers who created the nc files. And a plunge error appeared. It said it was 1.33mm too deep. Weird.

Same thing with the second file. So he went back and confirmed all was well… went to nc viewer as well… all blue. Material settings, etc were all good.

Checked the zero and it went everywhere we expected.

I shut the machine down. Let it rest. Then fired it back up. Went through the process. Funny thing is it retained zero. Had to confirm it but it was all still there.

Loaded a file we successfully cut with zero issues on Saturday. Plunge error. This time 1.77mm. Note → same material and depth of cut as today’s file.

So I came here and found a post from last year without any clear resolution. Man ran the file with no issues.

I did the same. No issues with either cut. It was def a success. However when I loaded the second file for this project, then the plunge error was now at 1.9x mm. Like its incrementing up :laughing:

Anyone have any ideas with respect to how to resolve this? Never have had this issue before. TIA.

this sounds familiar - we had similar issues on our Shapeoko 4, we didn’t have this issue until upgraded to a newer version of carbide motion on Mac, my guess is that it is a software issue.

The exact flow is: after we zero-ed all 3 axes, the machine go touches the bitsetter, then its z-axis zero will go off by several mms deep. If we do the zero process again it may come back normal.

I do not have access to the mac we use rn so cannot really tell which version it is.

Yes that’s the strange thing. Software has not be upgraded recently. And the file we ran Saturday without error, now throws this error. I’m leaning towards hardware but then again… I could be wrong. The cut? It executed the cut perfectly with no plunges beyond the depth expected (2.12mm on one, 3mm on the other). And when I tell you it was right on the money? We put calipers on both and they were perfect.

For the Z-axis this error can be caused by an interaction between tool length, how deeply the tool is seated, and the stock thickness.

I’d be right there with you IF →

  1. The bit is a 251 which is marked. The same bit, Saturday, same seated distance, same thickness of wood, just some toolpath variants. Files ran fine, no error or issue.

  2. Yesterday, same bit, same seat, same material, same file, now there is an error.

  3. And the error isn’t isolated to that singular file. We tried a half dozen.

  4. At the end, it cut clean.

However the error is still popping up in every run. I emailed support early yesterday morning. Still waiting on a response. Guess they had a busy weekend.

I assume you’re talking about the Bounds Check “WARNING” message, (not Error) when you load the file.

The way that works is the software compares the envelope (min/max machine limits) to the bounds of the toolpath (min/max of each axis in the path) using the current XYZ zero to determine where the toolpath is positioned within the machine limits.

In order for this to be accurate, you have to set the workpiece zero BEFORE loading the program.
And, the machine limits need to be accurate.

To determine your actual machine limits, click on the word “Position” above the readout to change the readout to machine position. Move the machine as far as it will go (hard stops) to the left, front, bottom
Do this without a tool so the Z can reach the bottom limit. Note these values

Now look in the file shapeoko.json and change these values to match

“travelX”: -685.0,
“travelY”: -535.0,
“travelZ”: -140.0,

The values are also stored in GRBL on the machine and are used for soft & hard limits. I’m not sure how they are synced, so you may want to change them too to match.