Kerf Issue

[Walt Langhans]

Hi All

I'm having a perplexing issue and I'm hoping someone can shed some light on it.

When I cut a 1" square of 1/8" MDF I get a 1" square of MDF minus a small amount due to the kerf. When I cut a 1" square out of 1/16" cardboard I seem to get a 1" square period. When I put the two up to each other the cardboard is overhanging just a tad but it's enough that if I butt to pieces up to one and other there is a gap.

I understand how the laser cuts and that you are going to get a bit of an angle due to how it focuses but do the differences in the materials thickness explain such the difference in size or does it have to do with the different properties of MDF Vs Cardboard or what?

Thanks

[Andrew Arndts]

How or what are using to cut this material?

[Doug Griffith]

Due to the hourglass shape of the beam, thicker material is going to have a wider kerf. |><| Not a whole lot though. It could be that because you are using more power to cut through the MDF, there is more incineration and char on the periphery of the beam. Just a guess.

[Chuck Stone]

What about stacking two sheets of 1/16" cardboard and cutting the 1" square.
If the two are slightly different sizes, there's your answer.

[Walt Langhans]

Oddly enough I use the same power setting to cut both the MDF and Cardboard and just vary the speed.

@ Chuck that's a pretty simple straightforward way to find out whats up, thanks :)

[Mike Null]

I think Doug has identified the problem. The easier to cut cardboard requires considerably less "dwell" time to make the cut, hence a smaller kerf.