Need Help with Hell Raiser...
 

I have a [link=http://www.hobby-lobby.com/hellraiser.htm]Hell Raiser[/link] that was purchased from H.L. I have actually had the plane for quite some time now but only have 3 flights on it. One was unsuccessful, but has since been repaired. My problem is that when I fly the plane it wants to roll to the left. I set my trim at full right aileron and it still pulls to the left. What do I need to do to fix this?

Here is my setup:
AXI 2208/34 Brushless
Jeti Controller
10x3.8 Prop
Using TP 1320 Lipo

Any help would be appreciated

RE: Need Help with Hell Raiser...
 

Chad,

We went thru about 5 Hellraisers, then moved on to other birds.

I would look for wing issues first. Correct as necessary.

a. Are the wings flat?... when you look down each wing from the end, are they "perfectly" flat, with no twist or bow.

b. Are the ailerons syncronized?... when you set one aileron FLAT to the wing, are all three others flat to the wing.

c. Is the horizontal stabilizer parallel to the wings?... when you look from the front or the back, you would see mis-alignment.

d. Are the two Elevator halves level with each other?... if you tape on some light straight item, like a balsa stick, on the surface of each elevator, are the sticks parallel when looking from the side?

e. Does the fuse have a twist or bow in it?

If none of these things are apparent to a noticable degree, you may have the dreaded HellRaiser Wing twist hula-hula happening in flight. What we found is detailed in the big HR thread [link=http://www.rcuniverse.com/forum/m_1970740/mpage_1/key_hellraiser/tm.htm]HERE[/link], but to summarize:

The top and bottom wings are not well braced to each other, and the top wing is not well connected to the fuse at the center kabane. When in flight, particularly at higher speeds, the top wing twists and rolls out of position in the yaw axis (twisting as look down on the plane). The drag on the wings holds it, and even compounds the problem, until you cut throttle or crash.

Hold the fuse, and push on the front of the upper wing leading edge at the end, you'll see the whole wing assembly roll and twist out of position. That's happening in flight... partial or total loss of aileron/roll control when it happens. Yours is probably doing it, but not really badly. I finally figured it out when I could see it in the air while it was flying straight away from me.

We added ice-cream sticks up thru the top of the fuse along the back of the Kabane thru the top wing, and glued it liberally with epoxy. We also ran secondary CF guy-wires from the front of the outer kabane at the top wing to the trailing edge of the lower wing so there was a front-to-rear offset to the new guywires. That really locked the upper wing in place, problems solved.

Hope that helps...

RE: Need Help with Hell Raiser...
 

Thanks for the help. Not sure if I want to go throught the trouble of all that extra bracing. I am sure that the wings are flat, and everyhting else is lined up as it should be. After all the troubles you went through, was it worth it once you got it in the air?

Thanks Again

RE: Need Help with Hell Raiser...
 

Chad,

The HellRaiser was our first foamy electric, and we did have a blast with them. My son and I flew them for 3 months and had a blast. However, it is a frail little bird, and we fly in persistent wind conditions. This little bipe doesn't like wind too much.

The bracing made the plane behave very well in calm conditions. If you just do the brace up the back of the kabane, that will help a ton. It only takes a few minutes to install, and really does a lot.

RE: Need Help with Hell Raiser...
 

If everything looks straight but it rolls try adding a washer to the engine mount on the left side, so that the engine thrust line angles to the right a little. I had the same problem although not as bad, and this really helped.

You are using the same battery as me, which is bigger than the designer really intended, so you (like me) probably fly it faster than intended. The wing will indeed twist at speed. And if you fly in heavy (5+ mph) wind like me, you might also see the tail flutter.

I reinforced both the main wings and the tail with cf rod.
Clark