Elastic Launched Glider C

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hunterboy+
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Re: Elastic Launched Glider C

Post by hunterboy+ » November 20th, 2012, 5:38 am

Thanks for the ideas I'll try them out.

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Re: Elastic Launched Glider C

Post by Orange714 » November 20th, 2012, 2:39 pm

Ah!!! Parallel Planes makes so much more sense now! I wish they mention that in their article XD Thank you soo much :)))

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Re: Elastic Launched Glider C

Post by calliekernick » November 20th, 2012, 8:20 pm

I have a couple of questions on how to make a glider turn effectively. Assuming I understand correctly, both the stab and the rudder affect turn. On the AMA site, it describes a right-left flight pattern, where the glider makes one right turn (due to the launch) and then circles to the left for the remainder of the flight. I wanted to clarify the stab's effect on this. Say you were looking at a glider from the back, so that the stab is closest to you. If the stab was tilted so that the left edge was higher up than the right edge, would this cause the glider to turn to the left?

Next, regarding the rudder. How should I manipulate it to reinforce the left turn? I read that you can insert a shim (1/32" thick and 1/8" wide, or something similar to that), but I wasn't clear on the details there. How exactly do you place the shim, and how does it affect the glider's turn?

Thanks!

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Re: Elastic Launched Glider C

Post by chalker7 » November 21st, 2012, 7:09 am

calliekernick wrote:I have a couple of questions on how to make a glider turn effectively. Assuming I understand correctly, both the stab and the rudder affect turn. On the AMA site, it describes a right-left flight pattern, where the glider makes one right turn (due to the launch) and then circles to the left for the remainder of the flight. I wanted to clarify the stab's effect on this. Say you were looking at a glider from the back, so that the stab is closest to you. If the stab was tilted so that the left edge was higher up than the right edge, would this cause the glider to turn to the left?

Next, regarding the rudder. How should I manipulate it to reinforce the left turn? I read that you can insert a shim (1/32" thick and 1/8" wide, or something similar to that), but I wasn't clear on the details there. How exactly do you place the shim, and how does it affect the glider's turn?

Thanks!
The stabilizer is effective at inducing turn (in the yaw direction) during low speed flight (the glide portion) while the rudder is effective at inducing turn during high speed flight (the launch portion.)

The description of the stab you have above will induce a left turn in the glider. How much of a turn will depend on the angle of its tilt and the size of your stab.

Rudder won't work particularly well at inducing turn during the glide, but you can get a little out of it. The shim you refer to would be placed between the fuselage and the back edge of the rudder, then glued in place to give the rudder a little angle.
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illusionist
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Re: Elastic Launched Glider C

Post by illusionist » November 21st, 2012, 6:30 pm

Many of the plans on AMA have wings that are bent at the ends (can't recall the term for it). Are these created by bending the wood itself, or by cutting and gluing the ends at an angle?
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Re: Elastic Launched Glider C

Post by _HenryHscioly_ » November 21st, 2012, 6:35 pm

Cut the dihedral/polyhedral break
then sand the edges so they match up when you glue them at an angle

http://legacy.amaglider.com/assets/outd ... iders.html
image at the very bottom

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Re: Elastic Launched Glider C

Post by _HenryHscioly_ » November 21st, 2012, 8:42 pm

http://www.theplanpage.com/Months/2802/ ... %20HLG.htm

the numbers and ratios from that website
Should i be sticking relatively close to them...?
According to the site, wing chord should be 1/7 of wing span(aspect ratio: 7)
What would happen if I make it 12"span, 4" chord(ar: 3)
or 18" span, 2" chord(ar: 9)
I have some thicker medium/light sheets, and I want to make some larger wingspan gliders with my friend tomorrow
We havent had any luck with our previous ones 12"span glider, relatively heavy, outdoor, throw, and no transition..more like throwing darts..xD

Left rudder trim(making plane tryng to left turn) would make turn spiral clockwise, looking from under/behind the glider?
and why right/left bank when launching?

Is there some configuration that'll result in much easier/better/consistent transition, maybe at the cost of sink rate and glide efficiency? shorter nose moment, more dihedral, more incidence?

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Re: Elastic Launched Glider C

Post by fanjiatian » November 22nd, 2012, 7:13 am

I'm really confused about the Time Machine.

What are the two lightning bolt shapes on the wings for?
What is the "Airfoil Details (Root)" box for?
Does it ask for 0.002" carbon fiber or 0.02" carbon fiber? I'm asking because paper has an average thickness of around 0.004"...

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Re: Elastic Launched Glider C

Post by jander14indoor » November 22nd, 2012, 8:54 am

_HenryHscioly_ wrote:<SNIP>Should i be sticking relatively close to them...? <SNIP>
Well, that is a 60 year old article... Not a bad starting place, but the designs on the AMA Glider site are closer to state of the art, might be better starting points.
_HenryHscioly_ wrote:<SNIPAccording to the site, wing chord should be 1/7 of wing span(aspect ratio: 7)
What would happen if I make it 12"span, 4" chord(ar: 3)
or 18" span, 2" chord(ar: 9)
Changing the aspect ratio of the wing changes the lift/drag of the system. Low aspect ratio > higher drag, high aspect ratio > lower drag. But with a limited span event like this, more chord gives more area gives more lift, trick is to find the right balance.
_HenryHscioly_ wrote:<SNIP>Left rudder trim(making plane tryng to left turn) would make turn spiral clockwise, looking from under/behind the glider?
and why right/left bank when launching? <SNIP>
Left turn/left bank/left wing low is a counterclockwise spiral from below.

Right/left. Hmm... chalker7 step in if I go way off base. Launch is at very high speed, tends to emphasize the control settings you make when you build the glider. If set to glide left and you launched left you'd tend to over control, continue the roll over and into the ground. So you force a right bank on launch, the controls try to correct eventually causing the glider to roll out and transition to the left.
fanjiatian wrote:I'm really confused about the Time Machine.

What are the two lightning bolt shapes on the wings for?
What is the "Airfoil Details (Root)" box for?
Does it ask for 0.002" carbon fiber or 0.02" carbon fiber? I'm asking because paper has an average thickness of around 0.004"...
Lightning bolts, are you talking about the squiggly details? Kind of elongated ones of these? ~ Those are showing grain direction in that section of the wing.
Yes the carbon fiber is 0.002 inch. He dropped a word there, should have said carbon fiber tow. He's adding individual fibers to the top and bottom of the wing to act as spars and stiffen the wing.

Jeff Anderson
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Re: Elastic Launched Glider C

Post by fanjiatian » November 22nd, 2012, 3:42 pm

By lightning bolt I mean the figure on one wing half approximately 140 degrees.
There's an arrow pointing to it saying 0.002" carbon fiber.

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