Help with school project

[Terry W]

Hi All This is a school project for 6 grade.

Wooden Glider

Objective

The objective of this project is to construct a glider that is launched by hand as the sole means of propulsion. The hand
launching will cause the glider to travel in the air as far as possible, and in as straight a line as possible.

Materials

The glider must be constructed from balsa wood. NO MANUFACTURED GLIDERS WILL BE PREMITED.

Any commonly available glue may be used.

No other materials may be used. Do not paint or stain thr glider.
Any gluing must be confined to points of contact. You can not use
weights to balance only balsa wood.

SPECS.

Wingspan- between 320 and 400 mm
Fuselage- between 300 and 400 mm
Tail length- between 80 and 100mm

TESTING

THE contestant must:
stand with the heels of the feet on the edge of the tape.
must launch ( toss, not throw ) the glider level to the ground
(i.e not thrown upward at an angle).
toss the glider straight outward away from the wall so that it remains between the marked lane. The marked lane is 3 meters
wide About 12 feet.
SCORING
The primary scoring will be the greatest of two trials, measured in meters.
The starting point will be the tape and the end point will be when the glider hitd the ground.
The glider that goed the farthest will be considered the winner.
In case of a tie, the lightest glider will be the winner.
Before launching the glider its tail should touch the wall.
If the glider (during flight) goes outside the marked lane, that
flight will be disallowed.

What do you all think.

I going to use a Baby Jazz FF glider with a 400mm wingspan
400mm fuse and 100 mm tail . how big should the rudder be?

I can use al the help I can get.

Thanks

Terry

[JCastle]

Hmmm.... Sounds like fun.

Given your parameters I would say that your primary concern is that it flies strait as that will give you a zero on the task. I think that generous dihedral, true unwrapped wings, careful alignment and a fairly large tail will help. The next thing to think about is the center of gravity. To heavy in the nose and you will sacrifice stability for glide distance. To heavy in the tail and your plane will stall and lose distance and stability. Many tests flights with molding clay on the nose will help you to determine the proper CG. Last but definitely not least is to make the plane as light as you can with as much wing area as possible. Choose the lightest balsa you can find and use lots of sand paper to make it lighter yet. Every gram you can take off of the tail area will reduce your total weight by a factor of 3 +-. You don't have any real stress put on the plane so don't be afraid to sand until your surfaces are paper thin. Remember that all of these factors are dynamic in that a change one place will effect something else. That's what we free flighters mess with all of the time. It's fun, that's why we keep coming back...

Good luck and keep us posted on your progress.:)

John

[Terry Lyttle]

We tried this decades ago, and the kid that won had the strongest arm; no doubt he became a pub darts champ. Clearly, the closer you get to trajectory as opposed to flight, the better your chances. Cheaters are everywhere, and there is nothing like a contest to flush 'em out.

HLG ain't worth it until the stopwatch comes out, then and only then does design and buildiing skill come out...

This reminds me of a Speed contest for rubber models, specs and all. After some spirited competition a guy showed up with the proper span, length, etc, and the loop of rubber. The wing was symmetrical, at the rear of the fuse, rubber was installed in a notch, and the model launched at winning speed through the course, end of contest.

THEN there is the guy (Bob Hungerford?) who munched his open rubber ship: a trip to the drugstore yielded 3 Sleek Streaks. I believe he WON by attaching the 3 motor sticks to 2 wings; correct me if I'm wrong, but I think the model was published in AAM as the HungerFord TriMotor!:D :D

[markwild]

Terry,
I think you're right. If it were a real aviation-oriented contest, then the contest ought to be about length of time in the air. But since it's not, and there don't seem to be any specs about the weight of the airplane, I'd construct the heaviest and strongest plane I could. I'd get about 10 sheets of heavy 4" x 1/4" balsa and glue them together, face to face, and cut to the longest length allowed. Dig a handle into the 4" x 4" fuselage so you can get a good grip. Then maybe glue a few sheets together to make a wing, and some leftover scrap for the tail. Use epoxy, because it's heavier.

Then, during the contest, heave the darn thing as far as you can. If you get a good throw, the inertia will carry it pretty darn far before it hits the ground. How far can you throw a baseball?

Too bad they won't let you add a brick for balast.

--Mark

[Terry W]

Mark I think your right. A friend at work said
make a balsa baseball and give it a good throw
that should win the contest.

Right now the baby jazz will go the length of
a basketball court (a small one) but to stay within
the 3 meters side to side you must launch from the
far left. The plane goes to the right and then comes
back to the left. I would like it to stay more straight
What do you think would be the best course of
action. Anyone?

Thanks for all the input

Terry

[Terry Lyttle]

Your only saving grace if they insist that it look like a "normal" airplane may just be a canard; with the wing at the back, and minimal control surfaces at the front, and a BIG fin, the lawn dart option resurfaces.

And as far as the weight is concerned, I got some "balsa" from one of the bulk suppliers, 1/4x3; you can have it once I take the nails out, it's part of the back fence, looking more and more like hemlock every day...

[Terry W]

With the way this teacher makes the rules
he would probably make me lauch the canard
backwards.

Terry