I don't think you want sandwich on this part. Sandwich is
  stiff up to a certain load but after that it collapses.
  I think you want solid carbon fiber. The part is relatively
  small, unlike a wing skin, so the weight penalty will be little.

  Paul Lamar ...No rotor no motor.

Paul,
 I think you could go either way. Manufacture of a sandwich part is
harder to set up though so a straight layup would be an easier way to
get going. So back to fire hazards; do we think the weight savings and
manufacturability is risk justified? Because I built an Autoclave we
could make these in.
Bill Jepson

Do you have a vacuum bag set up? Autoclaving these things
would be great. I guess you could shield it with fibrefrax and
and thin SS if you were worried about fire. Lots of
composite firewalls out there.
-- Paul Lamar ...No rotor no motor.

Vacuum bagging is no problem, we do it on almost every part we make.
I don't think i'm too worried about fire personally. The general layout
is important.
The spacers need to be inserted prior to thermal cure. The mold would
need to have
the sides needed for a motor mount built in. This part might be best
done male-molded.
The vacuum bagging would give a super finish anyway.
Bill

Good idea on the built in motor mount. We considered this
a long time ago sand cast in aluminum but the heavy weight was
discouraging.

Carbon fiber would be another matter entirely.
Here are a few old dwgs. It would have to be redesigned
for carbon fiber. I'll work on it.

-- 
Paul Lamar ...No rotor no motor.

Bill,
If you need some ideas on how to make a (male or female) mould, to exact
dimensions and perfectly round where round is needed -just ask and I will
tell you what I did. I won't go into the details here and take-up everyone's
time.
Is there any discernable shrinkage rate to make allowances for in carbon/
composite?
George ( down under)


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