Z Axis wrong direction

My Z Axis is going in wrong direction all of a sudden. Plus my when I do my probe it does x and y but it doesn’t go back to the spot it should. It’s like a half inch off. So everything I cut is way off. Anyone can help?

Hello Deryl, welcome to the group!

You probably just need to reverse the Z axis in the firmware settings. It’s setting $3 which uses a bit mask
to set the value.

Setting Value Mask Invert X Invert Y Invert Z
0 00000000 N N N
1 00000001 Y N N
2 00000010 N Y N
3 00000011 Y Y N
4 00000100 N N Y
5 00000101 Y N Y
6 00000110 N Y Y
7 00000111 Y Y Y

$3 – Direction port invert, mask

Don’t worry if you don’t know about bit masks etc. because it’s really easy to set if you use gSender. In the firmware settings in gSender there are separate toggles for each axis under setting $3, just flip the Z one.

Usually when I see a post about flipped Z it’s because the firmware was flashed and the ‘profile’ had the wrong settings for your machine e.g. flashing a LongMill Mk2 with Mk1 profile or vice versa because the Mk2 has direct drive one the Z while the Mk1 has a belt between the Z motor and the lead screw.


Thank you it worked!! But now there is another problem! When I do my XYZ it’s does the Z and X but when it does the Y it does not zero over the the plate again. It goes straight up after Y. I can’t figure it out. And I cannot cut anything because it’s at least 1 inch off center. Do you have any thoughts?

Are you sure that you are at zero after the probe? You don’t necessarily end with the bit at XY0 after the probe. You may need to use the Go To XY0 button to see where the zero’s are.

Are you saying that it never does the Z at all when you try to probe XYZ? Which touch probe do you have? Make sure you have the right one selected in gSender, auto touch or regular in the settings. It should work but if you have problems you can probe any axis and it won’t affect the others. You can do XY then a separate Z. You shouldn’t need to do them separate but if it gets you going, whatever works, right?

It does XYZ but when it finishes at Y. Instead of it going back over the block where it is supposed to go. It goes straight up .

So it doesn’t finish the XYZ probe right? If it’s just going up after Y, not up then over the block, it can’t do the Z unless I’m missing something.

I would try to do XY then a separate Z to see if that works. And which probe do you have? I only have the regular one, no experience with the Auto Touch probe.

One more thing is make sure the right diameter of bit is selected or use Auto for the tool with the Auto Touch Probe. Looking at gSender’s UI and another thing that maybe would mess up a probe is if the wrong corner is selected in gSender. At the top right of the Probe control tab is a icon, make sure the blue corner is the same as where you are probing.

I have the regular bone as eell

It does the Z first. I tried to take a video to show you , but I’m not aloud to upload it because I’m a new user. Basically it does the Z Axis, then does the X Axis but does not finish the Y axis. It doesn’t return over the block where it should go when it is finished.

My bad, I was thinking it did Z last for some reason, no wonder I was confused. I just did an XYZ probe on my machine.

This is were it ended after the probe, it did go up and then to the back at the end.

But it didn’t go to Zero after the probe.

I then used Go XY0 and then the Go to button for the Z and ended up here.

With the machine at [0, 0, 0]

So that’s the way it should work. Do you have limit switches installed? I was thinking that maybe you ran out of Z travel or something and that’s why it stops before moving toward the back, over the block. That can happen with long bits or thick work material.

EDIT: You can also check your firmware settings against this for the MK2 or this for the MK1, you can type $$ in the console and it will print your settings to the console.

No, I have no limit switches. I’ve had this CNC for over a year haven’t had this problem before . I’m gonna have to contact Seinci on Tuesday .

I really appreciate all your help. That’s what I love about this forum. Everybody helps everyone.

Your welcome, this was your first post so I was thinking maybe you were just getting started. Good Luck, I hope they get you sorted.

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Thank you…it was driving me crazy…lol :laughing:

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