Fiberglass vs. Fabric

Rich S. wrote:
"Lou" wrote in message
ps.com...

Well, maybe no sense right away, but the plans where drawn quite a
while ago. Like the Emeraude, the invention of fiberglass hadn't
arrived yet. Although I agree with the statement of making it as light
as possible, one of the reason's for this post is to discuss weight.
If this can be done with little or no weight penalty, then I thought I
would consider the experimental part of this group. After all, if Tony
Bingelis did it with good results, then why not consider it? I like the
idea of smoother, flatter, and more solid wings. If it turns out to be
25lbs or more, then I have to re-think this or just consider going on a
diet.


I understand where you're coming from, Lou - having had the same dilemma
myself while building the Emeraude. Fortunately we have a good builder
support group who could advise me on the nuances of that particular design.

Covering a wing with plywood that was originally designed for fabric and
open bays, will do more than change the appearance. An aircraft designer has
planned for the weight distribution (hence stress distribution) across the
span and chord. Skinning the wing will change both of those. You may
actually end up with a wing that is heavier, weaker and slower than before.
Do not make these design changes casually. Orville and Wilbur were
successful due to engineering, not trial and error.

First, ask yourself "What am I intending to accomplish by doing this?" Any
change requires more build time and usually more money. There can be other
penalties as well. If you're into engineering and test piloting as a hobby,
knock yourself out. It's your time, money and neck.

Re-engineering an older design can have no limit. Look at the fiberglass
version of the Beech 17 Staggerwing as an example. If you contemplate
changing a fabric wing to a skinned wing, why not go carbon fiber? How about
Nanotubes? Keep the end goal in sight.

Good Luck with your project!

Rich

P.S. The CAP-10C, the newest version of the Emeraude, now has a carbon fiber
spar.


Does it use that "pulltruded" carbon rod stuff for caps? That stuff is
incredibly strong, far superior to carbon roving in compression and tension.

John