Oooops!!.....................Forgot these.

 Butch

Sweet work!

Speaking of work the strike at Pratt is over and things are finally back to normal
(whatever normal is.... :) And I caught up on all the work that had to wait due to it.
So the plate is up on the Bridgeport and the center hole is cut and mounted on a bung
on the table to keep things concentric.

But one thing is bugging me on the LAEV prop though... Some thing is worrying me on
the carbon fiber / steel root interface area.

How are the fibers locked into the curved surfaces of the root? What retains em over
time and with strain and vibrations? Isn't the sharp (as it appears in the photo,
could be wrong here) edge at the end of the steel root section a bad area for stress
concentration? Is there a commercial product that uses this same design?

Happy Holidays to all!
Blake

Funny you should mention that Blake. Butch was asking me the same thing.
Here is the idea we are using. Ours is better as the thermal expansion
and contraction would be less of a problem not to mention that epoxy
sticks to steel better than aluminum. Never the less there will be a glass
insulation layer between the carbon and the steel to reduce the corrosion
effect. The first half of the blade is laid up and bunge cord is wrapped
around the fibers to hold them in place while the resin cures.
Plastic film is used of course to keep the bunge cords from sticking.
The bunge cord is removed and the other half of the blade laid up
with bunge cord again. When that side is cured uni direction fibers
are wrapped around the whole works to lock it onto the steel hub.

The feather edge on the steel hub actually reduces the stress 
concentrations in the carbon.

Paul Lamar
 
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