I'm Stumped!

After all these years, and after all these planes I have finally come up with a situation that I can't seem to lick. Here's the background.
The plane is a scratch built "Scared Kitten" Mc Coy .35 powered spinning a Tiapan 10x5 prop. Lines are 58' +- .015, and 1 1/2 oz outboard tip weight. Everything alligns well, with no warps or misalignment.
Here's the problem.
Level flight is fine, with good line tension. As soon as I try any manuever other than climb.dive or wing over, the plane looses line tension and the plane wants to turn into the circle. So far I have been able to save it, but it really is a "Heart Starter!"

Advise so far.

"build in downthrust"...didn't work.

"add tip weight"...didn't work

So, I am at a loss. What do you guys suggest?

Joe

Those manuvers are all "square turns". (duh) If it doesn't want to come at you on a wingover, or get loose at the top of it, it seems that it should be able to do the rounds, don't it? Maybe the stab angle (all directions) or making sure of some engine off set? Had an offset problem with one of our PAMPA planes, wanted no offset but upon crude measuring, found the tinyest hint of in set.
Not familiar with the scared kitten, but I am guessing no flaps. (??)
Maybe a wart on the outboard wing?
Wish I had more.
Bill

First thing I would do is move the leadouts forward. Also sounds like more wing weight than you should need. I wonder if your weight box is behind the CG? That might contibute to turning the airplane in. I've seen several Scared Kittens fly and they all flew fine, so keep after it.

It's a Bill Netzeband design. Like a lot of his stuff and Chas. Mackey's, it tends toward the shall we say "unconventional"?

>Level flight is fine, with good line tension. As soon as I
>try any manuever other than climb.dive or wing over, the
>plane looses line tension and the plane wants to turn into
>the circle. So far I have been able to save it, but it
>really is a "Heart Starter!"
>

Add a little (tiny amount) of rudder offset, or a rudder wedge. I would guess that the problem is that you have a tiny amount of inboard rudder or nose-in engine offset. As soon as the tension drops, the nose wants to turn in, and there's nothing to stop it.

First are the fuse and the wings 90 Degrees to each other . You have to do a triangle measure wing tip to end of fuse on both wings See if you have same measurement ...Sorry more to come I just got a Migraine and I lose my eye sight

Scott(can't see )Riese

I built one of those a number of years ago. It is a good design and flys very well, so that can be put to bed. It flys a lot like a combat plane so it may be faster on the controls than you are used to. I do not remember the wing tip weight but do remember that it was what seemed to be a lot. The leadout position is fine, mine was built as shown on the plans no adjustable stuff at all. There is a lot of rudder offset shown on the plans I cut that down to about 1/2 which was still a bunch. I do remember that the amount of elevator travel required was not a lot 15 degrees? Don't remember for sure now. Wild Bill flys his with a McKoy series 21 .40, and I used a C*x conquest .15 and Larry S. used a .15 Profi combat engine so I would say that the powerplant choice was very optional. I guess that is about all I can add, mine flew very well!

I used to like painting with dope but now I can't remember why

LAST EDITED ON Jul-21-03 AT 00:16 AM (CDT)
 
It's a pretty small airplane, so I don't see how a .35 would work, even a 7 oz. one like a Fox Stunt. Larry Scarinzi's Profi would weigh about 4 oz. A 10x5 prop would be enormous. I wonder if precession has anything to do with this.

Brett, Spent some time re-measuring and found that the engine is offest about 1% to the INSIDE! Re-drilled the mounting holes and now have slightly less than 2 degrees of offset to the outside. 105 degrees out yesterday so havent tried flying it yet, but might have solved the problem. will let you know.Thanks!
Joe:)

Hi, Joe - I built the "Kitten" a few years back and it really is fun to fly - definitely best when flown FAST! When I first flew mine, it had no engine offset and no tip weight. It did exactly what yours did. I added two degrees offset, around 3/4 ounce tip weight and one other thing - I moved the forward leadout back 1/4". The leadout spacing from the lead edge is now 2 1/4" and 4 3/4". It balances 2" back from the L/E and weighs just under 25 ounces. It's powered by the same engine as the original - a Glo-Torp .29 with a 9-6 wood prop. I used a bit less rudder offset than was on the plans. Yes, it does fly like a combat plane. My only complaint is that being so short coupled and having a tall gear, it is easy to flip over when landing on grass. Let me know if you want to see a picture of it.
Bob Z