I have been following this thread and swore I wouldn't get into it. Oh well, I have never been one to sit on the sidelines.
I have no qualifications what so ever to base this on but that doesn't seem to be stopping anyone else. As I understand what is being said, you can heat a piece of 4130 and let it return to room temp at a controlled rate it will be in a normalized state but if you cool it too quickly it will tend to get brittle. Wouldn't laser cutting heat the metal in the vicinity of the cut and not affect the surrounding metal very much? Wouldn't the mass of of the part act as a heat sink to cool the heated area more rapidly? Would the rate of cooling be beyond the point where the metal would start getting brittle? What are the characteristics of a part that has a brittle area around the edge of a hole? Wouldn't this tend to facilitate the start of a crack? I don't know the answers and I bet most of the posters to this thread don't either. If it were me I would track down an engineer with experience in this area. Steve Eberhart Just a whole lot of aluminum sitting out in the garage that will eventually have the tail number N14SE and go real fast Dana Overall wrote: >> >Mark Wrote; >> >So, my point is, no matter how you make the holes in your WAF's, >> whether it >> >be waterjet, laser cutting, drilling, or shooting a bullet through them, >> >there is no reason to worry about the heat affected zone, or losing >> the heat >> >treatment > > > Mark, and others, would you be willing to bet your life......but more > so, the life of others on this list who follow this shortcut that you > say works. Think about what a little "extra" care (in the eyes of > some) will get you. If money, over safety, is the factor in making > decisions, don't build an airplane. > > Not arguing, just food for thought. > > > > > Dana Overall > Richmond, KY > RV-7 slider/fuselage > http://rvflying.tripod.com > do not archive > > > > > > > > _________________________________________________________________ > Tired of spam? Get advanced junk mail protection with MSN 8. > http://join.msn.com/?page=features/junkmail > > > _______________________________________________ > see KRnet list details at http://www.krnet.org/instructions.html >
