Incorrect size cuts

[Lee Ellis]

Hi all, I have a blue and white DSP1060 with a ruida controller. I decided to check the accuracy of the machine and cut out a 50mm square from 3mm mdf.
The square that is cut out is 49.72mm and the hole is 50.34mm, is this expected and acceptable or is there a way this can be adjusted to make it accurate. It makes adjusting kerf settings a bit of trial and error.
I'm using Lightburn as my software and have tried several times on different materials and get roughly the same results.

[Gene Uselman]

Hi Lee- there is a correction in the vendor settings for that- forget the terminology and I am far afield now and cannot check for you.

[Lee Ellis]

Thanks, I heard that but looking for what settings to change. I have read and saved my setting but can't work out what I need to change

[Pete Cyr]

viewtopic.php?f=105&t=3528&hilit=100mm

Read this -download the link

[Chris Medcalf]

I don't think you have a problem as far as size is concerned. The laser is cutting on a line that's a 50.03mm square, with kerf 0.62mm wide. I think you'd be lucky to improve on the size of the object, but kerf is a bit big.
Look at improving focus and/or reducing power or increasing speed to get narrower kerf.
If you want a 50mm square piece, you need to cut outside the line. For a 50mm square hole, cut inside the line. RDWorks has options to do this automatically.

[Hank Morgan]

I agree with Chris. 0.62mm kerf is a little on the big side, but cutting a 50.03mm square from a 50mm request sounds about as good as it gets to me.