1/3 SCALE CAP 580 NEED HELP BIGTIME!!!!

[TeamFlatout]

Hey, I am trying to balance my 580. It is very hard to hover and takes a lot of up elevator to keep it in a hover and then I catch myself fighting it sometimes. Where are you guys balancing your 580 at??? I know most people have DA100's on the front of theres? Where are you balancing them at? I have a 3w TOC 120 on the front of mine. The DA 100 weighs 5.8 lbs and my 120 weighs 7.8lbs. Mine wing is in the front wing tube hole and I am balancing it 3 1/2 inches and its just slightly tail heavy. If I move back to 4 inches where the book recommends to play with the cg at it is just barely nose heavy. WHAT THE HELL can I do to make this thing hover real easy. Oh it harriers VERY WELL down on the deck and I can also do a side slip with it very well also if that helps any with the balancing issue.

Thanks

[Shawn Berkheimer]

Measure the thrust line, you may have down thrust.

Shawn

[youngflyer]

took the words right out of my mouth!

[TeamFlatout]

thought about that. Got tons of up thrust. I thought it was down thrust but its not. I put 3 washers under the bottom two bolts of the motor a couple of weeks ago. It got a little better but still fight it.

[Jaybird]

My Cap (H9) was the same way. It was not hard to hover, but it took up elevator the whole time. Also, to transition from harrier to hover, I had to blast the throttle pretty hard (and gain an unwanted 10-12 feet of altitude) to get the tail to come under unless I had a pretty stiff headwind. Maybe it's just characteristic of a Cap?

[3ddd]

the wing is low on the thrust line and the tail is high,they fight each other for control and the wing is bigger so it wins

[teryn]

	Quote: Originally Posted by Jaybird
	My Cap (H9) was the same way. It was not hard to hover, but it took up elevator the whole time. Also, to transition from harrier to hover, I had to blast the throttle pretty hard (and gain an unwanted 10-12 feet of altitude) to get the tail to come under unless I had a pretty stiff headwind. Maybe it's just characteristic of a Cap?

I am having exactly the same problem; nice to know that I am not the only one. I have been thinking about this a lot lately.

[AHP]

That's a Cap characteristic; my 33% is the same way. You'll get used to after ahwile. I've found that once it really starts winding up in a torque roll it becomes almost hands-off. You could try moving the CG back a little if it doesn't fly tailheavy now.

[bodywerks]

I have said it before, but try checking your vertical CG -i.e., hanging it by the prop with the prop parallel to the wing. You will find that the gear drops pretty hard. As stated before, this is typical for low wing aircraft like the CAP, and, in my opinion, is a contributing factor to your problem. This is why neutral planes like the Yak hover so easily - they balance better vertically. Even my 260 (which has a higher wing than the cap, but a higher thrustline than a Yak) is harder to hover than my Yak. Think about how a helicopter has to balance to hover neutral - it has to balance right on the shaft or it will want to drift in the direction of the heavy side.
You are quite limited as far as what you can do to obtain a better balance on your Cap, but moving all the radio equipment as high up in the fuse as possible may help.

[3dubya]

Yer hang it from prop, with very low wing, weight mass will be towards bottom of plane so will needs heaps of upthrust. There is no cg on wing when hanging on prop, it just acts as keel.

See this pic best Ive got to show how it all works, see plane leaning forward, with prop flat, and no loaded stab(no up elevator), that thing has about 1 degree of upthrust and torque rolls hands off in calm, it aint skill its all in the setup.

[3dubya]

Maybe abit of skill in the wind if spinning

[bodywerks]

You definitely have a heap of upthrust in that 300L!!! How's your vertical lines and power on/power off horizontals with it setup like that?