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Aug 15, 2007, 11:02 PM
XE521
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Quote:
Originally Posted by EricClark
AUW is about 12oz
Hi Eric,

forgot to ask, is this with pack and what pack are you using?

Regards. Karl.
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Aug 16, 2007, 11:45 AM
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Eric,

She looks pretty close to being ready to fly, and is a good looker too . Before flying her, you might try my old trick of holding the fuselage at 90 degrees so that the rotors are vertical, and then spin around on your feet so that the wind comes up from below the autogyro - avoiding obstacles of course!! You should find that the rotors will spin up nicely, and this gives a very crude idea of how "lifty" the rotors will be.

If there is wind around (you can have some of England's if you want), another good indicator is if you hold it into wind and gradually tilt it rearwards. I imagine that the rotors will be spinning in 100's of revs rather than !000's.

In my experience, the C of G for a side-by-side autogyro is not too critical, and a starting point would be on the rotor spindles. Some of mine have the C of G behind that, but they have stub wings and quite large tailplanes. Again, holding it in the wind should show if there was any gross tendency to pitch up or down, and you could change the C of G accordingly before risking a flight.

Flying-wise, it should go like a 3 channel rudder/elvator/throttle trainer, with the added bonus that you can't stall it in the conventional sense.

Good luck when you fly it, hope this is of use.

Al
Aug 16, 2007, 01:54 PM
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Thank you alfoot! That does indeed help. And Karl, yes that AUW is with the pack and its a 1300 3S1P LiPo so I should get quite a bit of flight time.
Aug 17, 2007, 10:42 AM
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OK! I went out this morning at 8AM for that maiden flight. Didn't go so well. The problem was, was that the autogyro kept spinning to the right all the time and I couldn't get it going the right direction. However, once the tail came up, it would go strait. My biggest problem was though, I think, was the rotors didn't have enough of an incidence angle. I could never get them spinning fast enough when the tail came up. I think they are at about 5 degrees and I am going to change that. I know, I know, I saw that when I built it, but I was like, mmm, I'll give it a shot. Well, I did, and now I know that I will need to give it some more tilt. Oh well, its my first autogyro. Live and learn.
Aug 17, 2007, 11:02 AM
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Eric,

What do you think was causing the turn to the right? I think that slightly more negative angle on the blades will be the answer to your rotor spin-up problem. Another quick and dirty test is to take your rotors and just drop them from shoulder height. Mine will spin a couple of turns before they touch down.

On the positive side, she lives to fly (better) another day

Al
Aug 17, 2007, 11:21 AM
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Hi Al

Well, the right turn I believe was the tail wheel. Also, the negative pitch on my blades are good (I think) because there was a light breeze when I got there, so I took my FA-61 and held it tilted back into the wind. Boy, those blades got a whippin. I think its just that they need tilted back more. If not, I will be adding more negative to the blades, but I think they have enough. But what do I know?

Plus, like you said, because it survived, I will be able to attempt to fly it again!
Aug 17, 2007, 12:16 PM
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Ah,

I see - sounds like you are right, a bit more aft tilt of the rotors then. That should be relatively easy to do. My twin side-by-side rotors are all set at 7.5 degrees aft, whilst the single, triple and quad are all at 10 degrees aft is that is any help. The motor is set at 5 degrees down as well, I couldn't see from your pictures where you had set the thrust angle.

If the tailwheel is not fixed, or not set to turn with rudder I can see why you had that problem.

Still, it looks like it just needs small changes, which is good.

Al
Aug 17, 2007, 12:26 PM
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Quite so Al. I have fixed it now making the following changes. I bent the tail wheel to the left a bit, broke off the front of the struts and blocked it up to get some tilt, epoxied everything back together, and now its ready to go! But.... it looks like its been through a war cause I have patches in the covering, and I haven't cleaned up the rough edges, only made it structurally sound and airworthy. I hope. Therefore, pictures will be coming in a bit once I have either totaled it, or beautified it. We shall see....
Aug 17, 2007, 03:31 PM
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Well... I got one picture this morning that is acceptable enough to post.
Aug 17, 2007, 05:17 PM
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Eric,

very good-looking gyro. Wish you luck with your next attempt.

Jochen
Aug 17, 2007, 05:20 PM
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Ok, so I went out for another flight a half hour ago. Its insanely windy but I didn't care. The rotors spool up quite nicely now, and even go into a buzzing, blurring spin (cause of the wind). But... it does work better now. Ok first the good news. It took off. Yes, it actually lifted off the ground! YAHOO! The bad news. It was too windy to fly. Hehe, other than that, I cannot tell if anything works or doesn't cause its too windy. Every time it took off, it would roll one direction (cause of the wind) and a blade would hit the ground causing it to slow or even stop and the other was going like crazy.(Never broke a blade though!) Then of course, it flipped over. Well, I did that about 20 times, just having fun and testing out a theory (to see if it was the wind or mechanical problem) until the tail broke. It needed replaced anyway, it was always too weak. Well, I hope to have a better flight report tomorrow morning/afternoon with some pictures/videos. Until then.

Eric
Aug 19, 2007, 02:39 PM
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Still workin on it....

Just a question though for any of you autogyro brainiacs...

The rotors of an autogyro are crucial, I am sure, but I don't know what works well, and what doesn't work. My blades seem to work fine, but I was wondering what is optimal, and what do you want to watch out for? Should they have a certain stiffness, should they be flexible, should they be thin or thick.... sorry for the stupid questions. I'm an autogyro newbie
Aug 19, 2007, 03:38 PM
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whoops, I edited this cause it posted double.
Aug 19, 2007, 03:39 PM
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Well its ready to go! Here's a pic of the remade tail. It looks *cough* pretty bad I will make it look good if it ever flies. No point in wasting my time.
Aug 19, 2007, 04:51 PM
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Eric,

I don't really know what the optimal blades for a gyro are supposed to look like, but I can at least tell you what I'm using: Areobalsa blades. They are rigid lenghtwise and torsionally, as, I suppose, blades for the 'normal' kind of gyro should be. And I aim at chordwise balanced blades, which in my case - I'm too lazy to put lead into the leading edges of the blades - means that the mounting holes are at 40% chord. And I take care to produce a good surface finish, even if I don't cover them with Monocote or similar.

Hope that your beautiful gyro stays in one piece from now on,

Jochen


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