Z Offset showing “In” (inches) instead of mm after 2.1 upgrade — machine not cutting/focusing correctly

LightBurn Software Questions
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1

Machine Details

Machine: OMTech 50W CO2 Laser

Controller: Ruida 644XS

LightBurn Version: 2.1.02

Computer: HP laptop, Windows 11

Is this a new issue: Yes, started after upgrading to 2.1.02

Description

After upgrading to LightBurn 2.1.02, I noticed the material thickness field is no longer visible in the Cuts/Layers panel. I located the Z Offset field in the Cut Settings Editor as an alternative. However, even after correcting my Control Units to mm/sec in Device Settings, the Z Offset field continues to display “In” (inches) next to the value instead of mm. This appears to be related to the units bug described in your May 21, 2026 PSA.

I did: I entered 3.00 in the Z Offset field for my 3mm basswood material after setting Control Units to mm/sec.

I expected: The machine to focus correctly and cut through the 3mm basswood material.

Instead: The machine is not cutting or focusing properly because the Z Offset field still shows “In” (inches) even after correcting the units, meaning it reads 3.00 as 3 inches instead of 3 millimeters. This has already caused wasted material.

Steps Already Taken

1. Went to Laser Tools → Device Settings → Dimensions/Units tab

2. Changed Control Units dropdown to mm/sec

3. Saved settings and returned to Cut Settings Editor

4. Z Offset field still shows “In” next to the value

Please advise on a permanent fix. I have orders to fulfill and have already lost material to this issue.

Thank you!

2

Did you see the Link Control and Design Units in the Device Settings window? It is right under the Control Units pull-down.

Device Settings Window
Device Settings Window850×679 78.2 KB

3

Yes, it reads just like your screenshot

4

As a workaround input 0.118 in place of 3 and test.

5

Hi Lavonia, I’ve tried to reproduce what you are reporting but after setting my control units to ‘mm/s’, I cannot see ‘in’ next to the Z Offset - are you looking at the word ‘In’ further to the right on the same line?

image
image684×441 25.7 KB

6

Yes, but I think I may have found the issue. I didn’t have Omtech Polar enabled and this is the machine I’m using. I will try it again tomorrow. Thanks for the quick response.