Villa

Hi mclina
That first takeoff will be a challenge. I learned to fly in the winter in PA. Eight inches of snow makes a good cushin for a bad landing. I would welcome the snow for the first test.

mustangman177

Has anyone put a set of main wheels on the cororoo and a steerable nose wheel ? It wouldn't be hard to do.

I too am aprehensive about hand launching a screaming .46 OS AX with tuned pipe. With the landing gear, it would be in more control until speed was built up for takeoff, and once trimmed out and flight characteristics learned, the gear could be taken off if desired for hand launching. Just thinking out loud here.

What should the cororoo weigh in at ? Mine is 4 lb. 14 ounce total weight.


Cary

xray328

My Feedback: (1)

I'm hoping for a little over 3#. I'm at 85% with a coro fuse.

I think adding gear would fatten the plane up a bit too much. It's supposed to be a flat wing and then you'd be adding landing gear hanging down there creating all that drag.

I'm building this plane for all out speed , so I'd rather take the chance tossing it.

Just make sure you're CG is dead on, and you should be fine. Once you get the trim worked out, the launch will be easy. It'll just takes a firm underhand toss if it's like the sickle.

The other thing about gear is that this will be landing pretty fast I'd imagine, and I don't want to bounce it in.

I'm used to making a low sweeping approach, and with the sickle I couldn't do that. It got really tough to control at low speeds. I had to come in low and fast and just chop the throttle into the grass.

My biggest concern is the size of this thing. I'm at 30" wingspan. How fast will that be out of sight at 100mph?

mustangman177

at 30" wingspan going 100+ MPH, DON'T BLINK !!! or it will be out of sight. I built mine to the 36" wingspan as per plans, so mine is heavier at 4lb 14 oz. with OS 46 AX.

I'm use to hand launching the PBF's with OS .25 FX, and they hand launch fine. This looks like more of a challenge to hand launch though. I suppose a quick underhand hand launch is achievable.

I would like to see a video though of someone hand lauching the cororoo, it would give me an idea of what to expect.

Cary

xray328

My Feedback: (1)

http://www.spadcombat.co.uk/spad/ind...c=select&id=15

A few videos in there, the first one shows the hand launch.

How did you get the 36" wingspan? The 36" wingspan made mine too long to fit on one piece of 2' x4' coro. I'm guessing you have 4x4 or 4x8 pieces?

I wish I could get 4'x4' pieces shipped economically.

I'm assuming that would be really expensive? I usually get the 2x4 pieces for that reason.

mustangman177

xray:

I had to splice a 3" section at the end of a 2' x 4' 2 mm. sheet to get the 36" width. I know you said in a previous post this might make it less stiff, but I took the chance.

the 4 mm. internal core is one piece though (acquired a 4' x 8' sheet through a local sign shop), and glued the 2mm outer pieces with splice to this. The sign shop couldn't get 2mm 4'x 8' sheets.


cary

mclina

Today looked like the best weather day I was gonna get for a while, so I took this thing to the field at lunchtime. There was still about 4" of snow on the ground, it was about 35 degrees and dead calm.

Three times I gave the thing a firm underhand toss at full throttle, and three times it made about a 50' arc right back into the ground. At no time did it feel at all like it wanted to fly. It didn't seem to respond to the elevator at all, and I never really had time to give it any aileron input. At full throttle, it felt like it wanted to pull out of my hand, but it didn't want to climb after I let it go.

So, what do you think? Could it be nose heavy? Is it just underpowered? Could it have been my launch technique? It is balanced at right around 10" back from the front of the fuselage.

And the snow probably did save me one prop. I broke two on the three launch attempts. Other than that, there was no damage.

Thanks in advance for your advice.

Villa

Hi mclina
You state "50' arc right back into the ground". Is this an inside loop? If yes, my guess is tail heavy. If there seemed to be plenty of engine power, you might try less throttle next time to give a little more time for correction. Maybe a click or two of down elevator. If it is an inside loop, you might consider having someone with you. I have no experience with a delta.

mclina

No, it wasn't a loop. It just went up a little bit, then nosed into the ground about 50' from me. If I had thrown it without the engine running, it would probably have done about the same thing.

The CG is forward of that was called for on the Cororoo plan, by about 1/2", maybe closer to 1".

I have hand launched my combat SPAD, which weighed the same, and used the same engine, and it climbs like crazy. There must be a trick to getting a flat wing to fly. Perhaps it is just way underpowered, like I was told by GreenSpeed way back in Post #4.

xray328

My Feedback: (1)

I'd suggest getting a buddy to give it a good firm toss. Maybe the engine doesn't have enough power to get it to flying speed. My sickle was like that on a .25FP, it would really struggle to get up, but then once it was in the air it flew ok (just barely). At least that could help rule out the design or CG as the problem.

What diameter prop are you using? Maybe increase the diameter/reduce the pitch?

How much throw did you have in the elevon?

Maybe reflex the elevons?

What was the final weight?

mclina

My dry weight was 48 ounces. The first prop I broke was a 9x6 and the second was a 9x5. The elevon throw was about 3/4" in each direction.

xray328

My Feedback: (1)

6 oz tank? So wet you were around 54 oz?

How about trying a 10x5 prop? That FX can handle it.

You need as much "umph" out of the hole as you can get.

microsprint9

Something must be wrong with either your engine or the CG, my 36" span delta weighs 42oz dry, has a 4oz tank and flies great on a Magnum .15XLS with a 8x3 prop, in the second pic you can see a pc. of coro glued to the bottom, this saves the prop on landing and gives you somewhere to hold on to for a good launch, my friend has one almost exactly the same as mine but the span is only 32" and it easily gets in the air with a slight underhand toss.

microsprint9

Dumb question, the prop is on the right way, right ? and it's not a pusher prop ?

Clean

Your cg is half to 1 inch in front of the roo cg dry. Think how much it is when full. Try to get the CG in the right place.

Also, the FX I think has more lug than you'd expect, try a 10x4 and then 10x5 but I'd think the 9x5.6 should have done it.

Get that CG right and see if that doesn't fix things. If you have the CG too far forward, you won't be able to pull that nose up anyways. You might try launching wiht just an ounce or two of fuel.

xray328

My Feedback: (1)

Good question about the prop. Not to be insulting, but it's been known to happen.

Villa

Hi mclina
Now that you described your 50' flight better, my guess is that it is nose heavy. Move the CG back a little. Resist the temptaion to use a lot of up elevator. Let it fly level till it builds up speed. I once mounted a prop backward. It still pulls the plane, but not as much as it should. Most people don't realize that the air will not go the other way, they assume they would notice the difference immediately. Not so.

mclina

Thanks for all the advice. I will move some weight back and try it with less fuel next time. I'll also try putting a 10x4 on it.

I did have my props facing forwards, but it never hurts to check.

Thanks all!

mclina

Today I moved the battery all the way back to the tail. This puts the CG dead on per the Cororoo plan. I also put on a 10x4 APC prop. I'm recharging the battery, but don't expect any flying weather for about a week.

MrGreenSpeed

Now the suspense is Killing Me, Get that thing in the AIR......[8D]

Seriously good luck on the next flight attempt, Sounds like You have all the right advise to get it in the air now.
Jeff

mclina

It was a beautiful day at the flying field. The sun really highlighted the clumps of dirt being thrown into the air as this piece of !@#$^ flew directly into the ground.

I am officially giving up on it. It was fun to build, it was fun trying to get it to fly, but I think I can find a better use for that engine and radio then being a shot-put.

I want a fun SPAD that I do not have to hand launch. I have one 36" piece of drainpipe left, and one sheet of 2mil coro. I think I will build a small stick-like plane, taildragger, with a flat wing.

Thanks for all of the good advice on this thread. You guys have been great. Look for the new plane in the next couple of weeks. The "sticker patrol" needs to take a little break from building or my wife will kill me.[]

mustangman177

mclina:

Sorry to hear about the demise of the delta. I was hoping for a favorable report, as I too am ready to maiden my Delta.

I too have given up on some designs-models that I thought would fly, put tooooo much time and money in just to be defeated.

I have added landing gear to see if this will improve take-off, I am way leary of hand launching. If all "would" go well, the landing gear will come off and then try a hand launch.

I've heard that taxing these on the ground is a big problem, since there is no rudder control. We'll see.

Am waiting for favorable weather to maiden.

Cary

draftman1

the demon will fit the bill on your materials you have left. I like mine, its very arobatic. the DPS is a great plane also. I started the wing on my corro star 60

microsprint9

mustangman177, since elevons usually use channels 1 and 2 for mixing, you could always use channel 4 ( rudder ) for nose gear steering only, a HS-81mg servo should be up to the task and it won't add much weight.

microsprint9

mclina, you have given up on the delta, but before you tear it apart have you taken a few minutes to check that the elevons were setup correctly?, i have never built a delta that wouldn't fly, but if your starting to nose it into the ground, you pull back on the stick and it still noses in, you either are telling it to go in ( elevator backwards ) or you didn't have enough control throws. I did this on a upstar, had the elevator backwards, plane went straight up, i pushed forward on the stick and the thing did a fast loop right into the shop, cost me a new wing and almost did it again after i fixed it until my buddy noticed the elevator was reversed.