Re: CAD LS-1


David J. Gall
 

Dave,

Mine WAS a considered comment. Why do you use my post as your jumping-off point? John tenHave's post came much closer to a "scolding" referring to Larry's advice as "half-assed" and such, but I must say that Larry got exactly what he asked for from everyone so far: considered advice.

There is nothing more considered than the overall safety of the community and the reputation of the airplane and preservation of its resale value as evinced by John's comments, the preservation of the heritage of innovation through cataloguers such as myself (bet you had forgotten about the Weishaar/Doyle carbon LS-1 that pre-dates the QAC LS-1, hadn't you!) and advice from the likes of Sam Hoskins recommending the LS-1 and an O-200, etc.

What Larry is positing is twofold: 1) That the GU canard is somehow more aerodynamically efficient and therefore worthy of having its structure upgraded to carry the loads of the O-200 in a Q200 type configuration; and 2) That the wheels should be mounted on cantilevered Cessna-style axles to permit convenient adjustment to the wheel alignment.

The latter is not merited. There is no need for frequent readjustment or micro-fine control over the initial alignment of the main wheels. Close enough is good enough.

The idea that the GU canard is preferable to the LS-1 is also not supported by evidence.

Proposing a major structural change to the GU canard in order to beef it up for the landing gear loads of a cantilevered axle and an increased gross weight when a suitable alternative is in the field flight tested and successful for over twenty years is just a waste of time.

Want me to scold? I can do that: Larry, your airplane is broke. Quit trying to redesign it and just fix it! There, he's been scolded.

Wanna redesign the Q200? There's a whole other Yahoo Group devoted to exactly that over on the Quickie Performance Group website. Let's talk about carbon spars and debate the efficiency of the LS-1 vs. GU canard over there, and leave the builder-advice for relatively stock and proven modifications here on Q-LIST.

As for your Q1 delemma, I'd rather have a Roncz Long-EZ airfoil on the canard of either a Q1 or Q200, but I'll keep any speculative engineering advice along those lines to myself on this list. That's what the Q-Performance Group is for. Meet me there!


David J. Gall

----- Original Message -----
From: Dave Klingler <voronwae@...>
To: Q-LIST@...
Subject: RE: [Q-LIST] CAD LS-1
Date: Fri, 22 Oct 2004 01:03:31 -0700 (PDT)



Folks, Larry started his post with "For your
considered comment". He's throwing out an idea which
on its face has some merit and he's asking for
intelligent discussion rather than a knee-jerk
scolding. Surely there are people on this list who
might like to talk about it?

Second, Larry also mentioned that his post was for
"those who are about to start cutting foam for the
canard". I fall into that category, so naturally I've
wondered about using carbon and better grades of foam
rather than the original Quickie materials (I have a
Q1, especially "primitive"). I'd like to see some
discussion on using modern materials on planes
currently being built. In addition, I'm re-engining
my plane with a considerably stronger engine (haven't
decided which one yet) and I keep wondering about the
disadvantages of using carbon versus e-glass.

I'm preparing to prepare to prepare to get my plane in
the air again after fourteen years of storage; the
previous owner ground-looped it and decided God had
sent him a message not to fly. I'm amazed and pleased
by the progress in materials since my Quickie was
designed (and since I spent three years building a
Seahawk). I've been spending a lot of time attempting
to decide whether I should be building an LS-1 or GU
canard, and of what materials it should be. I'm
willing to take as much time as it takes to be sure,
but please let the discussion continue in a civilized
and friendly tone so that everybody can benefit.

Btw, is there a general consensus that a new Q1 canard
should be LS-1? Or should it be a GU with VGs? The
GU issue was a big part of what made me store my
Quickie in the first place.

Thanks!
Dave Klingler
Albuquerque, New Mexico
(505) 255-0653
voronwae@...
Quickie N2LQ


--- "David J. Gall" <David@...> wrote:

Larry,

Don't bother! To quote Rutan: "Simplicate and add
lightness. If you're
considering adding something to your airplane, throw
it up in the air. If is
comes down, it's TOO HEAVY -- leave it out."

By the time you do all that structural stuff in
order to support a
cantilevered axle, you could have cut off the old
pants, sanded a five or
six degree bezel on the top, ground down all the old
structural glass (to
save the weight) and reattached the pants at the new
camber angle. No
re-engineering required. The stock pants have plenty
of room for the stuff
that goes in 'em, or you could section the pants and
widen them while you
have them off the plane. You mention the aerodynamic
efficiency as a reason
for wanting to retain the GU canard, how about
giving equal "weight" to the
structural efficiency (lightness!) inherent in the
original pants?

I do not agree with the assertion that the GU canard
is "more efficient" or
whatever your argument is for using it instead of
the LS-1 canard. Stick
with tried and true and get it flying first. If you
absolutely, positively
gotta do the re-engineering thing, either copy the
built-up carbon spar that
Weishaar and Doyle built twenty years ago (for an
LS-1, but usable for a
GU), or call Jim Marske and get a professionally
engineered graphlite rod
spar and landing gear SYSTEM designed from scratch.
That'll cost you about
$20,000 in development costs and consulting fees (or
more!) but the
aerodynamics is already proven....

Hmmmm. Back to plan A: Fix the broken wheel pant,
fix the alignment, do the
Jim-Bob six-pack, consult with your tech counselor
and HEED his advice, get
a pro to test fly it, then go fly....


JMHO,
David J. Gall
PS Main wing winglets = drag, drag, drag! There is
NO need to "increase the
efficiency" of the main wing. It does not EVER stall
so reducing the stall
speed of the airplane means reducing the CANARD's
stall speed.... Also, the
canard carries the brunt of the airplane's weight at
cruise, so if winglets
were needed anywhere it would be on the canard! Of
course, that would be
directionally destabilizing, so increasing the
canard SPAN would be the
preferred method... But either canard winglets or
increasing the canard span
will require increasing the main wing span so that
the main wing remains
protected from EVER stalling... The circle of logic
then puts you squarely
in the Waddelow increased-span camp, or taken to
extremes gives you a
slow-ass Dragonfly instead of a Fassssst Q200....
It's ALL been discussed
here before, see the archives I'm too tired to
re-hash it all again. The
Q200 continues to be one of the aerodynamically BEST
airplanes EVER! Don't
think you can improve it without a Jon Roncz AND a
Jon Sharp on your team!
Again, JMHO!

-----Original Message-----
From: larry severson [mailto:larry2@...]
Sent: Thursday, October 21, 2004 3:40 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] CAD LS-1


Anyone who disagrees, feel free to flame me on my
personal
e-mail address.
For considered comment use the net.

A thought for those who are about to start cutting
foam for
the canard on a
Q2 ( based on the published results of the VGs on
a GU canard
by JimP).

If you create the GU canard, then:
1. Cut off both tips (width of pants) (for gear
inside, or
not for gear
outside)
2. Cut out the center (3" wide) of the canard foam
full span
and round edges for the next step 3. Carbon fiber
glass the
cut out foam 4. reattach foam to new carbon fiber
spar and
fill the remaining grooves with flox 5. create a
3" wide X 1"
deep carbon fiber gear leg at the end of spars 6.
cut the end
tips to fit the gear legs (unnecessary for outside
geat) 7.
finish the wings per the plans 8. create the pants
per the
plans, except for the cutout for the gear legs.

9. Add the VGs per Jim P's #3 format tests when
ready

Would add 3 hours to the construction time and
$150 (carbon
fiber and VGs) to cost, but increase GW to/above
the LS1
while maintaining efficiency.
Adding winglets to the wing would help reduce
stall speed
further while increasing cruise speed by
effectively
increasing wing span and reducing drag.

Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...

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