Doodles...

"Richard Lamb" wrote in message
...

This one is a bit smaller.
call it 16 foot span and 15 feet long.
and maybe a full foot shorter in height.
I think it was 6o to 66 sq ft for the wing area is
about the same for both.

I can't see any scale or measurements on your sketches. Maybe I need better
glasses.

Or spec the Rotax 914 (turbo!) and a higher
aspect ratio wing (longer span) for those
mini-U2 missions....

Or an Apex T62-32?

http://avonaero.com/solar32.htm

You could lose the cheek cowls, reduce frontal area by a bunch and maybe
come in at your desired weight. Does a tailwheel airframe back up real well?

Rich S.

"Rich S." wrote:

"Richard Lamb" wrote in message
...

This one is a bit smaller.
call it 16 foot span and 15 feet long.
and maybe a full foot shorter in height.
I think it was 6o to 66 sq ft for the wing area is
about the same for both.

I can't see any scale or measurements on your sketches. Maybe I need better
glasses.

No, you just need the source files, which are drawn full scale.
These are pictures of the cad screen.


Or spec the Rotax 914 (turbo!) and a higher
aspect ratio wing (longer span) for those
mini-U2 missions....

Or an Apex T62-32?

http://avonaero.com/solar32.htm

You could lose the cheek cowls, reduce frontal area by a bunch and maybe
come in at your desired weight. Does a tailwheel airframe back up real well?

You, sir, are a man after my own heart.
Who wants to fly under powered aircraft!

But then there is the gas load (!)
Wet wing between the spars (no clue how much gas that is, but that's
all you get).

Climb to 10000 feet in two minutes and play sailplane?

And yes, it backs up real well.
At least on the ground.
Pick it up by the tailwheel and drag it around like a little red wagon.

It's a tiny little thing...

g

"Richard Lamb" wrote in message
...

But then there is the gas load (!)
Wet wing between the spars (no clue how much gas that is, but that's
all you get).

If it will cruise at 80 shp and consumption is 1.3#/shp @ sea level, you get
17 gph. That's got to decrease a bunch at altitude, doesn't it? 50-60
gallons ought to do it.

And yes, it backs up real well.
At least on the ground.
Pick it up by the tailwheel and drag it around like a little red wagon.

You could paint "Beta mode" on the wagon, I guess. I was thinking of the
geometry of reverse thrust on a full-swivel tailwheel. Talk about a ground
loop!

Rich "I *hate* the smell of kerosene in the morning" S.

"Rich S." wrote:

snip\


I can't see any scale or measurements on your sketches. Maybe I need better
glasses.

Rich S.

http://home.earthlink.net/~cavelamb/!L-ONE-A4-A.JPG

there is a reference dimension under the fuselage = 48"
and a little lower just above the frames is a foot/inch scale.

that help?

"Richard Lamb" wrote in message
...

there is a reference dimension under the fuselage = 48"
and a little lower just above the frames is a foot/inch scale.

that help?

Got it!

Rich S.

"Rich S." wrote:

"Richard Lamb" wrote in message
...

there is a reference dimension under the fuselage = 48"
and a little lower just above the frames is a foot/inch scale.

that help?

Got it!

Rich S..

Great!

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

Gear mounts on front side of the main spar (sorry, no tricycles)
5x5 wheels with MacGreary rubber,
band brakes with cables? or hydraulic actuation.

If need be (and it will), we'll rework the root using that 15%
Ribblet
airfoil (get all the buzz-words in!) or a 23012/15 (nil CP travel -
important
in such a tiny package) and add a P-51 style planform to provide
room for
the wheels.

now we're too cool...


Some other minor wing concerns:

At stall speeds, the root chord still has an RN (Reynolds Number)
of at least 3 million.

But the tips, being shorter, show barely 2 million.
So what does that imply?

Well, for one, many of the fancy airfoils get pretty lame below
three meg.
Which might result in:
Sloppy aileron control at low speeds at best?
Or even a TIP stall - i,e: a nice fun wing drop at the break (or
before???)

Looking for an airfoil that performs well at these low RN led me to
the
old NACA 4 digit 2312. It is considered a turbulent airfoil, rather
than
a laminar type. But it ought to hold on a little better when slow.

Which means that the rib patterns would be a pure-D beast to loft,
were if not for a little CAD magic.

The more ribs (assuming they fit right) and the thicker the skin the
better
we can hold the desired airfoil shape - but both mean _heavier_.
The dreaded C word - (compromise),

Oh golly, well, that at least scratches the surface....

"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.

"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?