When I built the first Bee, I used a wallpaper water tray. The length was 30”,
just barely enough for the balsa. Sadly, that tray was given away . . . At
first I was going to use the bathtub, but running in and out of the house to
the hangar didn’t seem too smart, i.e., the better half wasn’t too keen on the
idea.
Rick
From: Jake Boyd
Sent: Thursday, April 9, 2020 8:54 AM
To: orcachat@xxxxxxxxxxxxx
Subject: [orcachat] Re: SHOW AND TELL..
Rick, Your water tray idea is just what I need. I was using a Sheetrock mud
tray and it is too short requiring moving the balsa back and forth thru the
water. Thanks.
Jake
Sent from EKAJDYOB
On Apr 8, 2020, at 23:03, ORCA <ORCA@xxxxxxxxxxxxx> wrote:
Richard, when I built my first Lazy Bee, I did exactly what you did, except
for the using a car. For this Lazy Bee, I used foam board. Three layers of
foam board work well for the wing tips and a single board for the elevator and
rudder. I used the shipping box and some aluminum foil for soaking the balsa.
The snipping box is a USPS triangular box that makes into a long 3 sided, U
shaped holder for the aluminum foil. The aluminum foil makes a nice shallow
tray. Short bamboo sticks pushed through the foam board holds the rubber
bands against the lamination.
Rick
From: Leslie & Richard
Sent: Wednesday, April 8, 2020 7:31 PM
To: orcachat@xxxxxxxxxxxxx
Subject: [orcachat] Re: SHOW AND TELL..
Hi Builders,
So cool to see the magnetic building board in action. When I built the big
Lazy Bee I made templates out of 3/4 inch plywood, edges sanded smooth and then
covered with a layer of packing tape. After soaking the balsa in the bath tub I
coated each strip with Tite-bond II glue and then held the lamination to the
template with lots of rubber bands. I put the parts in the back of the old
station wagon to dry because the workshop temp was 40 degrees but inside the
car it was a toasty 65 in the sun.
Keep up the good work!!
Richard P.
On Apr 8, 2020, at 2:15 PM, Jake Boyd <dyob42@xxxxxxxxx> wrote:
The first step on the Rapide build. Water soak and Laminate two 1/16 x 1/8
balsa strips around a form to make the beginning of rudder/vert stab. The
elevators and horiz stab are done on a different form it same method.
<image0.jpeg>
Sent from EKAJDYOB
On Apr 7, 2020, at 18:54, Thomas Condon <tom@xxxxxxxxxxxx> wrote:
Was he really? Great on him! I know a lady on the current effort. Her
father makes the RC Sailboat kits that I race. She grew up in that and got a
degree in hydraulic engineering, or whatever they call it and is part of one of
the design teams on the new AC team. She has also soloed her sailboat around
the world.
Tom
On Apr 7, 2020, at 6:21 PM, ORCA <ORCA@xxxxxxxxxxxxx> wrote:
Tom C, Tom S was part of the Oracle Team USA’s efforts in the
American’s Cup. I was trying to pull a leg or
two<wlEmoticon-winkingsmile[1].png>
Rick
From: Thomas Condon
Sent: Tuesday, April 7, 2020 5:34 PM
To: ORCA List
Subject: [orcachat] Re: SHOW AND TELL..
Nope. It is the other Tom (me) who races sailboats, both full size and
RC. I'm sure I can make heads and tails of this if I try. My dad was an
Aeronautical Engineer, and we used to discuss these things a lot. I also did a
lot of work for Boeing simulating aircraft. But I just didn't want to wrap my
head around the aerodynamics at this time.
Tom (the other)
On Apr 7, 2020, at 4:36 PM, ORCA <ORCA@xxxxxxxxxxxxx> wrote:
Maybe Tom is thinking of racing sailboats instead of airplanes . . .
Rick
From: LEE LANNOYE
Sent: Tuesday, April 7, 2020 4:13 PM
To: orcachat@xxxxxxxxxxxxx ; Tom Speer
Subject: [orcachat] Re: SHOW AND TELL..
Tom, if you thought the rest of us would understand your analysis, I
think you are going to be disappointed, lee
On April 7, 2020 at 4:01 PM Tom Speer <me@xxxxxxxxxx> wrote:
So far, I haven't tried to analyze how the wake will roll up. I've
only used a vortex lattice method that has the wake trailing straight back.
I've attached a plot of the spanwise load distribution (green line) and the
corresponding lift coefficients (orange).
There are two principal sources of drag for a glider - profile drag
and lift-induced drag. The induced drag dominates at low speed, while in a
thermal, and the profile drag (plus other parasite drags) dominates at high
speed when penetrating the wind. Compared to Mark Drela's Allegro-Lite, this
design has 20% less induced drag.
I've also been toying around ideas for a flexible trailing edge.
This would act like a flap, increasing the camber at low speed and flattening
out at high speed. It would be totally passive, though, and not require a
servo. So it meets the rules for RES gliders. The flexible upper skin has to
have a precise stiffness in order to get the desired effect, and I haven't yet
experimented with what material to use. I'm thinking molded paper might do the
trick. The paper would be molded to the low-speed shape and then put into a
jig where I'd load the trailing edge with a whiffle tree. The paper would be
sanded until I got the desired deflection for the design load.
I'm also concerned about flutter, so I want to mass balance the
trailing edge. I'm thinking of using something like 1/32" balsa sheet for the
lower surface and putting a piece of music wire on the forward edge of the
balsa. There should be enough room inside the wing for this to move up and
down as the trailing edge flexes. A thin flexible piece of plastic (Mylar?)
would seal the gap on the underside.
The attached plot shows the profile drag for the section with
flexible trailing edge compared to several sections by Prof. Mark Drela of MIT.
It is competitive at high speed and has significantly less drag, and higher
maximum lift, at low speed. When you combine it with the savings in induced
drag, it may be feasible to get a 20% reduction in total drag at low speed
while still being competitive at high speed. I've corresponded with Drela
about it, and he's intrigued by the concept.
One big problem may be wing flutter, due to the mass of the fins
and horizontal stabilizers behind the elastic axis of the wing. The wing will
need to be stiff in torsion, so composite wing skins with the fibers oriented
at +45 deg would be in order. I've not done an vacuum bagging, so I've that
whole adventure ahead of me as well.
Cheers,
Tom
On 4/7/20 11:09 AM, Jake Boyd wrote:
Hi Tom S
Your 2m wing design is interesting. It would be interesting to
see see what effect the inboard wing tip vortices will produce.
Jake
Sent from EKAJDYOB
On Apr 6, 2020, at 21:53, Tom Speer mailto:me@xxxxxxxxxx wrote: ;
Not my design. It's by 3DAeroventures
(https://www.3daeroventures.com/shop/infinitywing). My only contribution is to
print it in LW-PLA instead of PLA.
However, I do have a 2m glider on the drawing board that is a
bit unusual. The configuration only makes sense because of the 2m span limit.
Cheers,
Tom
