Just another delta
01-13-2003, 01:24 AM
#1
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Just another delta
Excuse the bad pic... I'm no photographer.
Anyhow... I've cut this thing out, 32" span, 15.5 root chord, including elevons, 5.5 tip chord.
I've got plenty of material left, to change the sweep angle or wingspan later, if desired.
It's 4 millimeter coroplast, by the way.
I'm planning on the little Norvel .074 for power, and hoping it'll do ok...
meaning "fly", as I'm not expecting a speed demon or anything like that.
(Which is why I used a fairly large angle, as deltas go...)
I've roughened (with 80-grit file), and poked holes under the epoxied 3/16" ply engine mount.
I'm confident that the engine will be mounted firmly enough.
My question is, has anyone tried this without a "spine" or fuselage of sorts?
Obviously I'd like to keep the weight down, since I'll be using standard servos.
My all-up planned equipment weight, including full 1oz tank, comes to about 1lb even.
(Based on online weight specs... I have no lightweight scale)
3 servos (no rudder) 4.8 oz
Receiver 1.1 oz
battery 5.0 oz (Guessing. couldn't find spec. 600mah Futaba flatpack)
engine 3.0 oz
tank/fuel < 1.5 oz (Guessing)
I was just wondering if anyone here had experienced any success or failure
on a plane this size, while not using any sort of "spine" along the root chord.
I won't be using any spanwise stiffeners, either... at least for test flights.
I believe I'll probably try it anyhow, even if collective wisdom is against it
I'll be fitting the fin and radio equipment soon, and will post a better pic of the final,
along with the "success" or "failure" story. If for nothing else than for "future reference"
If it doesn't work out, I'll add a spine, or fuse of some sort, and stick an OS 32sx on it.
Anyhow... I've cut this thing out, 32" span, 15.5 root chord, including elevons, 5.5 tip chord.
I've got plenty of material left, to change the sweep angle or wingspan later, if desired.
It's 4 millimeter coroplast, by the way.
I'm planning on the little Norvel .074 for power, and hoping it'll do ok...
meaning "fly", as I'm not expecting a speed demon or anything like that.
(Which is why I used a fairly large angle, as deltas go...)
I've roughened (with 80-grit file), and poked holes under the epoxied 3/16" ply engine mount.
I'm confident that the engine will be mounted firmly enough.
My question is, has anyone tried this without a "spine" or fuselage of sorts?
Obviously I'd like to keep the weight down, since I'll be using standard servos.
My all-up planned equipment weight, including full 1oz tank, comes to about 1lb even.
(Based on online weight specs... I have no lightweight scale)
3 servos (no rudder) 4.8 oz
Receiver 1.1 oz
battery 5.0 oz (Guessing. couldn't find spec. 600mah Futaba flatpack)
engine 3.0 oz
tank/fuel < 1.5 oz (Guessing)
I was just wondering if anyone here had experienced any success or failure
on a plane this size, while not using any sort of "spine" along the root chord.
I won't be using any spanwise stiffeners, either... at least for test flights.
I believe I'll probably try it anyhow, even if collective wisdom is against it
I'll be fitting the fin and radio equipment soon, and will post a better pic of the final,
along with the "success" or "failure" story. If for nothing else than for "future reference"
If it doesn't work out, I'll add a spine, or fuse of some sort, and stick an OS 32sx on it.
01-13-2003, 01:44 AM
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Just another delta
my guess is, and its just a guess. I'd like to think its a school of hard knocks educated guess, though, is that you are gonna have problems with a 32" span, without something to stiffen it up around the elevon hinges.
Here's what i forsee happening: when you go to pull up on the elevator, the coro is gonna flex, and lock the elevons.
Flex the tips up and hold the middle, and you'll see what i mean.
There is a simple solution to it, though.
Get some elmers probond polyurethane glue, and some bamboo skewers from the local supermarket.
Wet the skewers good and wet, and put about 1" of polyglue in a flute. Push the skewers into the flute, and run all the way through the coroplast.
When the glue sets it expands, and will fill the flute solid. Doing about 3 flutes will make it very solid, and add about an ounce of weight.
If you do that, i think it'll fly great.
Here's what i forsee happening: when you go to pull up on the elevator, the coro is gonna flex, and lock the elevons.
Flex the tips up and hold the middle, and you'll see what i mean.
There is a simple solution to it, though.
Get some elmers probond polyurethane glue, and some bamboo skewers from the local supermarket.
Wet the skewers good and wet, and put about 1" of polyglue in a flute. Push the skewers into the flute, and run all the way through the coroplast.
When the glue sets it expands, and will fill the flute solid. Doing about 3 flutes will make it very solid, and add about an ounce of weight.
If you do that, i think it'll fly great.
