Z axis height after probing

I am using Charlie’s zeroing block. If I am carving some thicker stock and I zero the Z axis, after probing it retracts to high up to my homing switch. Is there a way to change a setting that wll have it retract like .25 of an inch or so? Zeroing works great, just retracts to high.
I use Charlies program and use picsender. The safe Z on picsender is set at .25
Older 1000 mm X-Carve with X-contoller using picsender.
I am sure I am missing something.

I am still learning about gcode. I guess I will just have to play some of the values

Post the macro string that you are running. It should contain a command to trigger the retract and you should be able to adjust that amount to whatever youd like it to be.

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There’s a line similar to this:

“G91 G0 ZX.xx”

But be careful. Charley most likely sets this assuming that you’ve got at least the entire block to travel plus additional movement to clear the top before moving the bit over. These are relative moves so it moves the set distance from wherever it is.

You can lower the value but have to be careful of how deep you put the bit against the plate.

That’s also a way you can work around this: put the bit as close to the surface as you can and so when it does the Z motion, it won’t go as high

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Hi Patrick,

The g-code that zero’s all three axis is set up so that no matter how low your bit is when you start the sequence, it will retract high enough to clear the touch plate before moving over the top to zero the Z Axis. It is set to raise the Z axis 0.8 inches up before moving over the top of the touch plate. If you hare having a problem with it retracting too high due to thicker material and a limited amount of Z Axis travel, there are a couple of things you can try.

#1 Preferred Method: Start the sequence with your bit as low as possible to the work material. Keep it just high enough that the tip of your bit does not drag the material and that the collet nut and or magnet holder will clear the top of the touch plate. This will reduce the height above the material that it will travel to and may solve your issue.

#2 If you are using a shorter bit that you can’t lower down so that it is just about touching the work material then you could edit the zeroing g-code to change the retract height to suit your needs. To do this, open the zeroing g-code file with a text editor like windows Notepad. Look for the following block of code towards the bottom of the file:

G91 G0 Z0.8 F10
G91 G0 Y-0.625 F10

On the first line of this section edit the G91 G0 Z0.8 F10 to a smaller value such as G91 G0 Z0.5 F10. This will change the height the Z axis is retracts after touching off on the Y axis to .05 inches instead of 0.8 inches before it moves over the top of the touch plate to zero the Z axis. After zeroing the Z Axis the bit will still retract .125 inches before it moves off the touch plate and ends the code.

You can set that value to what ever works best for you but be sure to use caution because if it is set to a value less than the actual thickness of the touch plate Z axis then I can’t promise you that it will clear the touch plate when you run it.

If option 2 above doesn’t make sence to you then don’t do it. Instead let me know how much of your bit is extending below the surface of the touch plate when you run the code and I will provide you with the change to make to the g-code.

Of course, no changes will work if you don’t have enough travel available in your Z axis for the bit to move over the top of the touch plate.

If you need further help with this I would be happy to give you a phone call and help you work through this issue.

Best of luck,

Charley Thomas


What plug do you need @PhilJohnson? If it is the plug for the X Controller I can send you one. I order them by the dozens and it would cost me less to send you one than it would for you to buy just one.



Oops, I don’t got’s me one of them there thingy’s.



Thanks everybody for the reply. Everything is working for me. I just make sure the bit is as close to the surface as possible before probing. Thought I was doing that, guess I was being lazy.