Laser cutting balsa wood

I made some tests vector-engraving and cutting 4 different sheets of balsa wood (for building lightweight model-airplanes):

Chiara didn’t have still experience in laser cutting balsa, so I had to start testing from scratch. The top sheet is 6 mm thick medium density balsa (175 kg/m3), the 2nd is 6 mm light density (100 kg/m3), the 3rd is 3 mm and the bottom one is 1.5 mm. On the left of each piece there are 6 vector-engraved lines. On the right 3 cuts of 20x20mm squares. They all had different power and speed settings, to see what the best combination of power and speed was.

What I found to be the best setting combinations to CUT the different thicknesses were: 6 mm: min. power 48%; max. power 60%; speed 60 mm/s 3 mm: min. power 48%; max. power 60%; speed 140 mm/s 1.5 mm: min. power 48%; max. power 60%; speed 200 mm/s For VECTOR ENGRAVING: min. power 16%; max. power 16%; speed 200 mm/s

The width of the kerf resulted 0.2 mm.

Problem: Where the laser stops moving (at the start and end of engraved lines) more material is burned away. In 1.5 mm balsa holes were at the end of the lines:

In order to avoid this, I should have set the min. power lower than the max. one.

I also found a really nice tutorial for RDWorks at the following link: http://wiki.daap.uc.edu/sandbox/groups/infocenter/wiki/15e06/attachments/0f24a/RDWtutorial.pdf?sessionID=65378693ff25c1e6c477b4904e56bbea8d930297

I’m going to make more tests…