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May 15, 2009, 08:13 PM
Bernoulli+Newton=Lift
magic612's Avatar
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DARK ANGEL: An IPS-powered canard glider - PLANS, PICS, VIDEO!


The other day I was fiddling around working on a "windy day" plane. As I sat there thinking, I noticed an old GWS IPS motor that was sitting on my workbench. I thought, "Gee, what a waste. I should design something for that." So instead of working on the "windy day" plane (I was having a mental block anyway), I started designing a very lightweight glider.

Pictures below are the result of that effort. Of course, you don't NEED an IPS motor to fly this - actually, it would do quite nicely with a simple Blue Wonder, especially since you'd only need an 8" prop, whereas my IPS uses a 10" prop. PLUS, you wouldn't need to build this out of 3mm Depron like I did if you use a Blue Wonder, you could make it out of pink or blue FFF. Or even 6mm Depron.

But to make it light enough for the IPS, it probably has to be the 3mm stuff. It has a KFm1 airfoil, a 20" section of carbon fiber (but a 3/16 dowel would probably work in a pinch), two 6 gram servos and whatever small size battery you've got laying around, since the IPS's only pull about 2-3 amps. Smallest ESC you've got; but 5 amp is ideal. That's about it!

I'll be frank - the only test flying I've done so far is the 50 feet across my backyard, and the rudder seemed a little sluggish. But it was hard to judge when the average altitude was only about 4-5 feet, and total distance flown was 50 feet. But it sure seemed like it was going to do okay, and I KNOW that with a small brushless on there, it would make a neat, lazy glider.

Any interest? If so, I'll do some more rigorous testing when the weather calms down and clean up the plans. I think I might name it "Dark Angel." Not trying to be macabre or anything, but with the dark grey Depron and the shape, it seems to fit it. I thought about adding some red stripes to it too.

EDIT: PLANS ADDED - TILED AND UNTILED VERSIONS.

CG is 1.875" / 47mm back from the LE of the center section of the wing, where it's the "open section" for the prop (if that makes sense?).

Also, it's not shown on the plans, but I'd STRONGLY recommend some spars/supports of some kind on the sides of the motor mount. Note in my pics / video that I've put some blackened bamboo skewers from top of the motor mount area out towards the side supports. I also fashioned a "cover" (not on the plans) that helps, too.

A CF rod or dowel should be placed underneath the wing that goes at least 4" or so beyond each side of the fuselage booms.

Video is on page 2, post #18.
Last edited by magic612; May 22, 2009 at 07:53 AM. Reason: 48" tiled and untiled plans added
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May 15, 2009, 08:21 PM
My plans are in my blog
Rusty-Gunn's Avatar
Dave, this is a very nice looking plane. I like it a lot. Looks very cool.
May 15, 2009, 08:40 PM
Bernoulli+Newton=Lift
magic612's Avatar
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Thanks, Rusty!! Seems like it should fly pretty sedately, given the short test flights I did. Hope to get some flights in tomorrow, if the wind cooperates.
May 15, 2009, 08:49 PM
Registered User
PatricMichigan's Avatar
Who DOESN'T have an IPS gathering dust? lol
Patric
May 15, 2009, 08:53 PM
My plans are in my blog
Rusty-Gunn's Avatar
Quote:
Originally Posted by PatricMichigan
Who DOESN'T have an IPS gathering dust? lol
Patric
Yup, I've got one, too. Buried under a haystack of dust.
May 15, 2009, 09:24 PM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Quote:
Originally Posted by PatricMichigan
Who DOESN'T have an IPS gathering dust? lol
Patric
Well, see - that's kinda what I was thinkin'!!!

I figured most of us probably have one of these laying around, gathering dust, so why not use it? Well, if you want to, that is.
May 15, 2009, 10:03 PM
My plans are in my blog
Rusty-Gunn's Avatar
Well, I might add it to my already growing list of planes to build...
May 15, 2009, 10:04 PM
Bernoulli+Newton=Lift
magic612's Avatar
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Quote:
Originally Posted by Rusty-Gunn
Well, I might add it to my already growing list of planes to build...
Dude, I still need to get to building some of YOUR planes! So... it's okay. I'd totally understand if you didn't get to it anytime soon.
May 15, 2009, 10:39 PM
For us He died, in me He lives
Jimmy JFlyer's Avatar
Hey Magic, great timing on this thread.
Take a peak at what I just posted...
https://www.rcgroups.com/forums/show....php?t=1050283

Do you think with the IPS A this would make a good slow flyer for the front & back yards?

Jimmy
May 15, 2009, 10:54 PM
Bernoulli+Newton=Lift
magic612's Avatar
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Quote:
Originally Posted by Jimmy JFlyer
Hey Magic, great timing on this thread.
Take a peak at what I just posted...
https://www.rcgroups.com/forums/show....php?t=1050283

Do you think with the IPS A this would make a good slow flyer for the front & back yards?

Jimmy
Hi Jimmy -

Honestly, if you've got 40' x 70', I'd say no. My back yard is, at best, about 40' x 50', and this plane moved pretty quickly across it, and doesn't have great turning ability. It's a slow turning glider, requiring a wide radius.

That said...

I would recommend you take a look at my BYOB plane, particularly the 32.5" wingspan version. Check out the video - I'm flying the 26" version in my backyard - 40' x 50' area.

I did see your thread before, but didn't recommend this plane because you specifically stated you were looking for something that would fly with a high AoA. The BYOB doesn't do high-alpha, high AoA flying, but with a Johnson 250 or even the IPS on the 32.5" version, it ought to work fine, I would think. The Johnson uses a smaller prop, if IIRC, so that might be the better option - assuming it will deliver enough power (watts).

Hope that helps!
May 16, 2009, 01:57 AM
skumgummi dave
Magic:

Plans would be cool when you get a chance.

Thanks;

Dave-
May 16, 2009, 07:41 AM
7up
7up
,ɯǝ ʇoƃ ɐʎ ɟı ,ɯǝ ǝʞoɯs
7up's Avatar
I'm diggin' this one, especially with the abundant IPS motors I have saved over the years. I still use em'..

Nice one Magic!
May 16, 2009, 12:06 PM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Hey, thanks guys!

I'm working on cleaning up the plans. Unfortunately, I can't test fly it today - average windspeed is 15mph, with gusts up to 30mph. That's a recipe to have two halves of one 7 ounce plane! Hopefully tomorrow's weather will be more cooperative.
May 16, 2009, 06:06 PM
My plans are in my blog
Rusty-Gunn's Avatar
Yep, we had ugly weather all week, too. I look forward to any flight reports.
May 17, 2009, 09:52 AM
Bernoulli+Newton=Lift
magic612's Avatar
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Maiden report - SUCCESS!


Well, against my better judgment (ha!), I went ahead and maidened DARK ANGEL this morning. The reason I say "against my better judgment" is because the wind is a bit choppy this morning - it's running between 2 and 10 mph. (I tell ya, it's REALLY nice having a weather station in town, because I can look at the live wind speeds and direction).

Anyway, despite the wind, I really wanted to get this bird in the air. Figuring it might better to have bit of extra mass on board, I loaded it up with an 800mAh 2-cell pack. Throttle up - off she went! Well, sort of. With that pack, it's tipping the scale at around 7.25 ounces (that's only 27 to 30 watts per pound, mind you). Considering all the drag it's got, plus a paltry IPS motor/gearbox, I really couldn't gain altitude much above 20-25 feet. I flew it around in a couple circuits, and brought her down to change packs.

This time I went with with the 500 mAh pack, saving me a half an ounce of weight. Now we're looking at just a hair more watts per pound (29 to 33), but what a difference it made! I wouldn't say it "leapt" out of my hands, but the throttle authority was much greater. I easily brought it up to 60-75 feet in short order. This is with 2 - 10 mph winds, mind you - going both up and downwind. Not bad at all.

Previously I was worried about the rudder authority. Honestly, my fears were unfounded, as it's not a problem at all. At full tilt rudder, she definitely will turn. Not snap turns like a sport plane, but it turns those 48" of wings around with no problem. There's NO STALL whatsoever. I kept trying to push the nose up with the canard, to force it into a stall - it wouldn't do it. It just mushes forward and keeps on flying.

I think this would make a great canard trainer - though as a trainer, I'd prefer to put a Blue Wonder on it and probably make it out of 6mm Depron of FFF (it could probably be built to 8-9 ounces without issue). Either way, whether you build it to make a neat looking canard glider or if you use it to get the "feel" of how a canard plane flies, it's a nice, easy-flying plane with no bad flying characteristics that I've noticed yet (granted, this is only with two flights of experience).

A couple things I'd like to check on first: One, the canard felt, at times, a little thin. I'm wondering if a slightly larger control surface would help with that. Also, I felt like sometimes I was pulling the stick down (sometimes all the way!) to gain altitude, rather than simply using throttle management - though that could have been the wind, too. I may have to add a degree / degree and a half to the canard as a whole to give it the right neutral trim. That's about all I can think of that may need tweaking.

I'll get the plans finished up and posted as quickly as I can. I think some of you guys will really enjoy this plane. I'll try and get a video posted sometime soon, too.


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