Z Axis Offset for Different Layers

LightBurn Software Questions
1

I was wondering if anyone has used the Z Axis Offset. I assume with this you can adjust the Z axis height for each individual layer for cutting or engraving. Example: Layer 1 is engrave, set z axis for engrave height. Layer 2 is cut move laser down for cutting

I have a job that has 3 Layers, The first layer is engrave, the second two layers are cut.
So i would set the depth of cut manually for the first layer which is engrave before i start the job.
On the second layer i set the Z Axis Offset for 5mm to move the laser down 5mm for the cut
No problem there.
What about the third layer which is also cut?
Will the Z Axis move back up and i need to also set the third layer for 5mm Offset or will it stay at the current Z Axis Position which was 5mm from the starting position

OK. Did a test and it looks like the Z Offset is Accumulative from the original position. So to do this i need to do the following

  1. Set Z Position for Engrave focus depth before starting job
  2. Set Z Offset for 0mm for first Engrave Layer
  3. Set Z Offset for 5mm for second Cut Layer
  4. Set Z Offset for 10mm for third Cut Layer

It does work but the downside is it increases job time because it repositions Z for every individual design element. Might be more efficient to just leave Z Offset at 0 and then run each layer one at a time

2

There are two options, you can enable relative z-move in device settings or not.
If you have relative movements enabled, the laser is returning to initial height after each layer. I just created some gcode to test it (one layer with z-offset of 5 mm and the other with 2 mm)

; Cut @ 3000 mm/min, 60% power
M9
G0 X30Y33
G0 Z-5
; Layer C02
G1 X65S600F3000
G1 Y-69
G1 X-65
G1 Y69
G1 X0.5
G0 Z5
; Cut @ 5000 mm/min, 10% power
M9
G0 X88.5Y0
G0 Z-2
; Layer 03
G1 X57S100F5000
G1 Y-40
G1 X-57
G1 Y40
G0 Z2
M9
G1 S0
M5
; return to starting pos
G0 X-119Y-69
M2

If you turn off relative z-moves, then you have a material setting per layer that can be used.
grafik

1 Like
3

Thanks. I have relative move turned on for Z. I’ll turn it off and see if that changes anything

4

Bonjour, cela arrive si on relance un ou plusieurs passages en cliquant sur autoguidage. L’idéal pour une seconde passe est de laisser la tête du graveur dans la position en fin de première gravure

5

Turning off Relative Z Moves Only didn’t work. But if I turn on Optimize Z Moves that seemed to keep it from readjusting the Z axis for every item engraved. The only thing I noticed is after running the job you need to rehome before starting another job otherwise the laser doesn’t know where its at and crashes into the rail. This is also mentioned in the Lightburn manual. So i have
Enable Z On
Relative Z Moves only On
Optimize Z On

And the Z Axis Offset is based on the initial Z axis setting. So if you want the layer to move down 5mm, use 5mm in that layer. If you want the next layer to move an additional 5mm use 10mm in that layer.

So:
Set Manual Focus
First Layer Z Axis Offset set to 0mm
Second Layer Z Axis Offset set to 5mm
Third Layer Z Axis Offset set to 10mm

If you set the Third Layer to 0mm it will move back to the original starting position

6

Z Offset Test File:

Manual Focus before Starting Job
Then Run Job

First Layer - 0 Offset
Second Layer - Moves Down 5mm from Start Position
Third Layer - Moves Down 10mm from Start Position
Forth Layer - Moves Up 10mm Back to Start Position

This is for my Atomstack A70 Pro. Other machines may work differently

Z Control

Z Offset Test.lbrn2 (20.5 KB)

1 Like