Darkly Labs Community

Kerf offset

In the Lightburn cut setting editor, what does kerf offset do?



What I gather is … suppose you were cutting out a small ring from some material and the width of the ring part was critical to end up being 1 mm. You layout an outer circle then an inner circle 1mm in from it  but the laser beam has a width (kerf) that if it followed the lines drawn it would infringe into the 1mm by half the kerf. To end up with a true exact 1mm ring you would apply the kerf offset to both the outside (of the outside circle) and inside (of the inside circle).

It is fantastically useful for veneers.

Copy the existing layer into another new layer. Then apply an offset of 0.05mm to your chosen “inner” layer.

When you cut the two veneers, the inner piece will fit perfectly into the outer…

Keep in mind that this leaves you with the “opposites” that will have a larger gap. Still use these, but fill them with some sanding dust and CA glue or, if you want fast - Timbermate.

I absolutely love my A3 Emblaser!


It’s as Woodpixel says - ‘Kerf’ is the diameter of a cutting tool, which in our case is a laser. If you use a table saw to cut wood, kerf is the thickness of the blade. If you need to make a hole with a very exact diameter, for example to hold a shaft or an inlay, cutting a hole of that size will end up making it slightly large, because the beam isn’t infinitely thin.

You can measure the kerf by cutting a shape like a circle or square of known size and measuring the result. The difference between the measured size and the size you requested is the kerf width. If you enter that value in LightBurn as the kerf offset when cutting a shape, LightBurn offsets the shape by that amount right at the moment of cutting, without affecting the original vector.

This makes it easier to resize things - if you designed the shape with the kerf offset built in, but then scaled up the shape, you’d be scaling up the kerf offset along with it. Using the kerf setting allows you to scale the shape without affecting the kerf offset.