Lightburn DXF to Estclam cutting size error

Hi All,

I have 3 columns of boxes in Lightburn measuring 200mm in width with the x positions set to 0, 203 and 406 so in Estclam I only have to cut the 1st and 3rd box which leaves me with the 2nd box automatically cut out as I cut out box 1 and box 3 as parts so the 3mm gap between each box is for the endmill.

In Estclam I open the DXF and create 2 large boxes (column 1 and column 3) using the parts and hand pointer like below

After cutting the parts out I have noticed that column 1 and column 3 are 197mm in width and column 2 is 200mm in width so column 2 is correct but the others are 3mm too narrow. Am I doing anything wrong or is it an Estclam error? I’m sure I could just extend the box 1 and box 3 by 3mm in Lightburn but I shouldn’t have to so would rather know if I’m messing up somewhere.


3mm smaller on a 3mm bit(half a bit size on left and right ?), it looks like your path doesn’t follow the outer perimeter but go straight over the line/ the middle of your bit cut on the line.

I don’t know estlcam yet but according to documentation i would say you might need to use a 1.5mm Offset:


I was going to look at the offset after reading your post but I can’t seem to find it in my version of Estclam even though it is the latest windows version. Thanks for the idea though, I will check or use Vcarve which looks like overkill as I’m not doing anything fancy. Not used Vcarve in anger but looks too complicated compared to Estclam.

Just had a thought, would the middle box not be 197 if the bit was cutting on the line of box 1 and 3 and not on the outer edge?

Estclam is cutting on the outside of the box in Estclam so I think if could be a problem with the software.

That’s how the “part” path works. The drawing should represent the actual size of the thing you want to make. If your drawing includes the kerf of the cut, then you can cut on the line with “engrave”. But that seems like a very difficult way to do it.

Hi Jeff,

The drawing is actual size as I want 200mm wide boxes and I have 3 mm gap each side of box 2.

I’m going to do a 4 box test which has 50mm x 50mm boxes to see if it’s the end ones that are wrong to pin the problem down.

The normal way to do this is to draw the boxes 200mm wife, and leave at least 3mm between them (a 1/8" bit is 3.175, so even more gas for 1/8" bit). Then choose part and let estlcam cut on the outside of the box.

You are trying to be tricky by making the parts of the design include the kerf, but that will only work for these straight shapes. Besides, things like adding a finishing pass won’t be possible if you do it your way.