View Full Version : Kerf thickness

Ed Barber
01-04-2017, 7:59 PM
Hello everyone , I'm new on this forum and fairly new to engraving.
I use the trotec speedy 400 and I am interested in inlays of different types of wood.
How do I adjust for the thickness of the kerf? Any suggestions would be appreciated.

Bert Kemp
01-04-2017, 8:11 PM
Getting the best focus will give you the thinnest kerf.

David Somers
01-04-2017, 8:15 PM

If you do a search in the Forum on Inlay you will get a slug of good hits on doing inlay with lots of details.

Essentially though, you need to determine the size of your kerf for that lens/material combo. You can do that by focusing carefully on a sample of your material, then getting your speed and power the way you want it for a good cut. Then cut a vector square for the material. Once done, measure the width of the square hole you just cut. And then accurately measure the width of the square piece you just removed. The male and female parts if you will. The difference between the measurements is the kerf.

The hits you get with your forum search on SMC will go through all the details you need.


Darren Wilson
01-04-2017, 10:06 PM
Hello Ed,
There is a great instructables on calculating Kerf, by Adam ANT, works a treat!

David Somers
01-04-2017, 10:43 PM
Ed....apologies. I just realized I told you to measure the inside width of your square hole, and the outside width of the square you cut out and subtract the one from the other and that was your kerf. I should have finished that thought and said you need to divide that number by two and that would be your kerf.

Sorry for the omission. Like leaving an ingredient out of a recipe!! <grin>

John Noell
01-04-2017, 10:55 PM
And once you know size what you are targeting, you can use the contour function in CorelDraw to add whatever is needed. Also, because the cut of laser beam is angled (due to shape of focused beam), if you cut one piece right side up and the other upside down, they will mate perfectly with a bit of pressure.

Kev Williams
01-05-2017, 3:47 AM
For doing inlays, the formula is very simple:

for the inlay, you cut it needed size plus tool width.
for the cavity, you cut it needed size minus tool width.

Since the tool is the laser beam, start with .006" as tool width and experiment.

to add or subtract for tool width in Corel, use the contour tool and create a single outside contour of the original shape, the offset value will be half the tool width, in this case .003". Then create a single inside contour at .003".

cut the inlay with the outlined shape, cut the cavity with the the inlined shape.

IF your beam width is in fact .006", the part should fit the cavity perfectly. If it's too tight or too loose, adjust the offsets by .0005" increments

Mike Null
01-05-2017, 8:50 AM
I use the method described by John.

Ed Barber
01-09-2017, 9:29 PM
Thank you all for your input, gets me one step closer to my final product.