Problem with CM4 upgrade

The Z-axis can be reversed for a couple of reasons — the most usual is that the Z-axis plate is installed upside down.

The community has a basic page on this here:

The Z axis plate is installed correctly. It worked right when I was using CM V3, and that is what has me puzzled.

In that case, you must have reversed the Z-axis setting either in Grbl 0.9, or when you updated to 1.1, or it may be that you haven’t updated the settings of Grbl 1.1 — see: for the latter

If you need to reverse the Z-axis manually, see:

This is the settings screen that I get

Yes, that’s the one — be sure to re-send the settings if you haven’t — the toggle homing button you see on the screen grab in the docs isn’t there anymore.

This is the screen I get after I send the settings. As you can see, it doesn’t have the correct model in the box, and when I try to open and home it just starts to lower the Z instead of moving up, and I get the same errors as listed above.

Forgot to attach the photo

I left the firmware at 1.1 and went back to CM V3, and I am running a program without running the router just to see if it is working correctly, and so far, so good. I’m not going to worry about V4 right now if this works.

I suspect you’re still on Grbl 0.9 — please check, Grbl 1.1 w/ EDIT: CM3 is not supported. (EDIT: Grbl 1.1 works with CM4 — that and Probe support are why we have it)

See GRBL 1.1 and Carbide Motion 4 to revert.

Err…Will mistyped.

OK: GRBL .9 with CM3
OK: GRBL 1.1 with CM4

no other configurations work. You cannot reliably use 1.1 with CM3. If you sent settings before upgrading, they are wiped out on the upgrade. There is a very specific order this upgrade has to be done in.

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IDK, but as you can see the Shapeoko is running GRBL version 1.1 and Carbide Motion 3, and I just loaded and cut the project in the picture. It runs great, and none of the usual skipping when jogging. ???

There have been some pretty unusual problems caused by running Grbl 1.1 with CM3 — it’s neither supported nor recommended.

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And your homing switches are turned off.

Good luck.

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OK, I Followed the instructions in the link from Will and tried to go back to 0.9 and CM V3, and it didn’t work at all. I am going to retry 1.1 with CM4, but in the updater I have 2 files. One is MACOSX, and the other is Carbide GRBL updater. Do i have to install both files? Please pardon my ignorance on this, but it is getting the best of me.

The MACOSX files should be metadata left over from preparing the archive on a Mac and can be ignored/deleted.

If you have 1.1f, installed, then all you should need to do is install CM4 and use that.

If you have trouble sending the defaults, just send them manually.

I haven’t installed it yet, and how would I install the defaults manually? I apologize for taking up so much of your time, but am grateful for the help and advice.

Crib the settings from: and

Check in w/ — obviously we need to work up a canonical list of the Grbl 1.1 defaults for each machine.

Hi Will,
I worked with Brandon on this problem, and we found that the Z limit switch was bad. I put a new one on and started CM4 and hit jog and it started homing and Z worked great but Y kept hitting the side. I did a continuity check on both Y and X switches and there is continuity there, but are the switches NO or NC? I get continuity when I push the buttons on the switches.

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I believe the switches are NO since a jumper works to upgrade.

OK thanks. I will have to do some looking on here to see what could be the problem. The switches are working right if they should be NO.
Thanks again!!