Good Morning from Wisconsin!!...

To keep this thread going a bit longer here are a couple of thoughts:

Some time ago I explored the possibility of having blades made by the process of "pultrusion". In this process a die, somewhat like an extrusion die is formed to the outer profile of the shape desired...in this case an airfoil.

Then strands of fiberglass, or carbon soaked in an epoxy resin are fed into the die and pulled through into a curing chamber. The shape that is formed can be as long as the strands of fibers.

For rotor blades, the parts could be cut to length.

I found a company in Pennsylvania (I think) that does this process, but the cost of making the die and the amount of material that the whole autogyro world would use, is simply not economically practical.

As far as a CNC die is concerned, there is a fellow near Chicago who has made molds for Michael Selig at the U. of Illinois for his airfoil studies. The name is Yvan Tinel, 1904 Techny Court, Northbrook, IL 60062. He reckons that a mold (top and bottom) would cost about $1500-2000. In order to avoid ridges he takes several days of constant milling to make the cavities. Usually runs automatically over a weekend. Phone is 847 509 1805.

Maybe we could get several of us to share in the cost to get a mold, then pass it around?????

Bill