I had an interesting conversation with a friend of mine about laser
cutting..he's been in the business for about 20 years. He mentioned that the
FAA has never officially approved laser cutting as a means of working with
aluminum for structural applications. It has something to do with stress
risers and the heat involved and what it does to the temper. The reason heat
is a factor is because of the reflectivity of aluminum.....it acts like a
mirror. It takes longer for the light beam to cut through and more heat is
built up in the process. Steel is actually easier to cut with a laser than
aluminum. However, some of the newer lasers are better able to cut aluminum
without building up so much heat. In any case, we experimental builders are
not necessarily constrained by what the FAA will allow on certified aircraft.
Also, if the part is non-structural, it really isn't a problem. As a matter of
fact, my friends company cuts instrument panels for one of the aircraft shops
here in town. He said that If I supplied the CAD file, a typical instrument
panel would cost between $75 and $100 to produce. I asked how they figure
their rates, since I hadn't a clue. They charge by the inch, (of the cuts)
plus whatever setup charges are involved.

I'm not sure if I am going to let them cut my instrument panel or not. It's
tempting, considering the amount of work that it will take to flycut and drill
one. But at any rate, I now know a whole lot more about laser cutting than I
did before. So I thought I would share.

Dave