gSender Surfacing Inconstancies

Hello Again!!! …lol.
Hoping someone can help me out…

gSender Surfacing

Input all my XYZ measurements
(see attached images)

cut depth & max: .5mm - 1.5mm

if you reference the images, you can see that it’s cutting 8mm (ish)

there was a slight bow in the material but nothing that would warrant this drastic a pass…

Can anyone tell me what I’m doing incorrectly?

Thanks 4 the Help IN advance.

How did you set your Z-zero?

Manually, with paper.

If you jog your Z 10mm, does it actually move 10mm?
If so, can you share the resulting gcode for the facing op?

I have calibrated all axis a while back, yes I believe it’s jogging is true.
I’m not sure what you mean about sending the gcode,
Sorry, very new to the CNC world.

You can get the G-code from the surfacing tool by clicking on “G-code Viewer” at the top right of the surfacing window. You can then copy to clipboard and paste it into a plain text file. Then you can drag and drop the text file into a post to share it. That way someone can look at the code and see if that’s the problem.


Here you go…

Gcode.txt (4.0 KB)

From what I can tell the G-code looks correct. It looks like 3 passes each at 0.5mm for a total depth of 1.5mm. Maybe @NeilFerreri will see something I missed.

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Gcode looks ok.
What machine do you have and what’s your $102 value?

I have the Longmill MkI
Not sure what you mean by $102 value

It almost seems like a buggy control box or a virus (which I’m not sure could be a thing)

While I was writing the post my router actually moved on the X axis by itself… Thought it was Strange…

Thanks everyone for trying to figure this out, just new into CNC and it’s been a frustrating journey, this forum has helped tremendously.


$102 is the setting for Z axis steps per mm, it’s how far the motor has to rotate to move the axis 1 millimeter.

The setting can be accessed with the firmware tool. The default for your LongMill is 200 steps/mm. You can also see the settings by typing $$ in the console and the console will display all the firmware settings. You can change a setting in the firmware tool or with the console. For example entering $102=200 in the console would set 102 to 200.

If your interested in learning more about settings, G-codes or error codes I have some resources that I use.

Firmware settings
G-code reference
Alarms and error codes

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This is excellent information, thank you.
I’ll look into this.

@RicP Did you get this issue sorted out?

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Yes. Well, not figured out, but my machine has been running well since.
I think I’ll chalk it up to Operator Error, Although I’m not sure what I could have done, but will monitor future projects.
thanks for your help…


I have had somekind of the same issue in one of my first attempts to surface a piece. I had it in a spiral out motion 1mm for cut depth and 3mm for max cutting depth. The machine spiralled down causing the spindle to get stuck, pulling the piece out of its clamping and finaly burning out the makita in a spectacular display of illegaly smoking at work.

I think it has to do with the difference between the cut and max depth. I make sure those are the same since.
I also have installed lower amp circuit breakers for the longmill and for the router and a switch in my office to cut power to the complete machine if needed.

I too have no idea what went wrong but am keen on preventing it ever happening again.
I kept the piece as a reminder.

Looks pretty simular.