Thread: Doodles...
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Old January 11th 06, 12:30 PM posted to rec.aviation.homebuilt
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Default Doodles...



"Rich S." wrote:

"Richard Lamb" wrote in message
...

Now, your assignment, should you choose to accept it, is to draw up
a reeeeeaaaaaaly light weight retract system for it bg.


Moi? (In my best Miss Piggy voice). I'm a retarded firefighter - no engineer
fer sure.

The Emeraude uses the 23012 and I'll bet the Zephyr does as well. Add a bit
of washout to soften the stall.

I would 86 the idea of retracts and go with an RV-type gear off the engine
mount. No spar reinforcement needed, you can keep the fuselage on the wheels
when the wing(s) is/are removed, & other weight-saving advantages.

JMHO
Rich S.


Damn! But it worked for Huckleberry Finn!
Oh well, the extended roots don't really fit anyway.

The wing on the Zephyr looked long and narrow (higher aspect ratio due to
a pretty short chord). I didn't download his plug-in to get a look at the
rest of the stuff. 3 meg on a land line? Not today. But it is an interesting
design.

I've always rigged my parasol wings flat - no washout. The thing is so
lightly loaded it doesn't really stall anyway. But I agree that this wing,
with the tiny tip chords should probably have a bit of twist in it.
Even if it does cost some top end speed.

And you touched on one of the issues I still have with this one.
Landing gear attached to the wings can be very inconvenient if a wing
needs to be removed. So we start looking at a 3 piece wing.
Center section and removable outer wing panels with the gear mounted
on the center section. Sounds like a better idea. But consider how much
that complicates the wing structure! (damned C word anyway!)

We would need about a foot of center section sticking out from the
fuselage for the gear mounts. (I don't want any of that in the cockpit
area - in case of a gear failure. Don't want any failed structure
coming into the cockpit (i.e.: pilot). )

So, while I agree that it would be a lot more convenient to have the
plane on the gear when the wings are removed, I'm not sure that the
extra weight and complication would be worth it on such a small
ship.

BTW, this is the one place where Bruce had problems too.
His first try failed rather early (just widened the stance some).
I know he fixed it, but haven't heard how well it's standing up
(no pun intended).

Lastly, unfortunately, RV style off the engine mount (which olde
timers still call Wittman-style gear) won't work here because
we don't have 1) room behind the engine, or 2) an engine mount!

Yes, I have one sketched in. But more likely, for a VW engine,
the engine mount is nothing more that 4 aluminum spacers just
long enough to keep the flywheel and rear exhaust stacks to get
clear of the firewall.

Something I hear a long time ago, and have come to believe -
"Better is the mortal enemy of good".

Richard

are we having fun yet?