Bucky,
You failed to mention whether it is for a fixed pitch prop (bolted to
the crank flange or hub extension) or CS prop (bolted to the hub with
standoffs). In any event, a spinner without a forward bulkhead
(especially an unbalanced glass one) puts incredible work-hardening stress on
the back plate. Unfortunately, fixed pitch props have nothing
to support a forward bulkhead while the CD piston cup allows one to
construct such a support.
If you wish to create a carbon back plate, use the current one as a male
plug to create a female mold. Then it is just a matter of laying in the
carbon cloth and carefully vacuum bagging the setup. Remember to make
it strong enough to withstand the flexing.
Another thing that can be done is to build a carbon flange inside the
aft part of the spinner to match the back plate and attach the spinner with
machine screws through the back of the back plate and thru the flange to nut
plates.
Have fun,
Grayhawk
In a message dated 11/19/2009 3:03:21 P.M. Central Standard Time,
buckyw@sbcglobal.net writes:
I have a prop. spinner backing plate with 500 +
hrs. I found cracks around the mounting holes ( at the prop hub ).
I did not install the doubler kit sold by Lancair. I know
this is an ongoing problem for many other builders as the
plates crack with or without the kit and sometimes with less
hours.
My question is this-- has anyone made one
out of carbon fiber for the 320/360 series with a constant speed prop? I
know Brent Reagan made one for his LNC4, but we all know Brent can make
anything.
I would appreciate
any input positive or negative, about fabricating one out of
carbon fiber for the 320/360 series.
Thanks,
Bucky
Whittier