Hi guys,
I have a Sig Somethin Extra with an OS 70 Surpass and I have encountered a weird phenomenon when attempting TR's. Sometimes when I start a hover this plane torques hard and fast to the RIGHT. It seems to happen if I put the throttle up slowly. The only thing I can figure is the spiral slipstream is twisting the wings, ailerons, and tail feathers opposite the engine torque. It amazes me every time it happens. You would think that if the engine could create that force then the two torquing forces would cancel each other out.
This plane is 6lbs 3oz which I know is heavy, but that OS 70 pulls it out of hover albeit slowly. One other thing I've noticed is that when I used an APC 13 x 6 prop I had great hover thrust, but it would hardly start the torque roll. I changed to a 12 x 8 APC and now it torques hard to the left, usually. I'm still working on a complete TR IRL, I can torque indefinitely in the sim now. I think my flying skills have surpassed the aircraft capabilities. I enlarged the rudder, and am planning to enlarge the elevators but I think that unless I can drop a pound or two off this plane I'm swimming upstream.
Has anyone seen the torque to the right?
-Tom

Yes,
Are you holding right aileron? You may not think so but you may be doing it without noticing it. If you have a lot of prop plast and some large ailerons a little deflection could cause it to rotate that way.

I'm not an expert, but I believe I have experianced the same thing with my Morris the Knife. If I'm not quite giving it enough throttle, the nose suddenly will drop to one side slightly and it will do a rapid 1/2 roll. Like you, I was very supprised when it first happened; it doesn't seem to make much sense. Anyway, stay on top of the throttle. As soon as you reach 0 air speed, go to the throttle position for a good hover.

Thanks Wayne and Oodie. I'm going to try a Top Cap with that 70 Surpass and see if I can't drop 2 lbs off too.

Ha! I thought I was the only one to have this happen. I don't know but it is very possible that I bump the right aileron and WOW, round she goes! It happens, and spins so fast that it's alarming. I gotta believe in my case it's me applying right aileron. Of all the things that I'm being careful of when TRing, I really watch out for that. Sorry for you, but it makes me feel better that I'm not the only one!

Thanks

John Wells

Maybe it is snaping to the right with the rudder corrections ...
I don´t have a SE but I think it can improve enlarging the lateral area arround the nose and CG and adding airfoil to the tail; just some ideas...

Wingspan,

So, that means youre getting a Top Cap?????? Ya know, I think you have gone through more planes than I have underwear in the last two years. LOLOLOL Have you ordered it yet?

LOL I know what you mean. I did have quite a few airplanes last year. It was very interesting and a lot of fun having all the different engines and airplanes. But I don't like having a huge fleet, it's too much maintenance. I don't think I have any of the same stuff I bought last year, but I don't regret selling it all off like I did. The only thing I really liked was the 1/4 scale CAP231EX because it was big, but it was a pile. If I do another giant aerobat I'm probably going to go gas with it on a quality airframe. Ignition is just so much more reliable than glow, and a whole lot cheaper to run! Maybe that A-plane will satisfy that need for a big one.

So much for not taking on another project........I would look at that seduction freestyle before ordering the top cap though.

I am going to spend 50% of my time building the ultralight and 50% on models. After the 31% A-plane and the video plane are done there will be plenty of time for a Top Cap. There's only 25hrs left between the two of them. I don't want to spend a lot of time or money on an airplane I'm going to learn TR's with.

Does that also includes the 40 hours a week you are supposed to be at work?????? LOLOLOLOLOLOL

Well, 50% of my time is for the models, 50% is for the ultralight, 50% is for the job, and the other 50% is for the family!

hey wingspan! i too got a sig something extra with an os 70 surpass!!! it is heavy to, i moved to servos into the tail section, the rudder servo and the elevator, i am also using hitec 605s. i did add one inch to the rudder also.. how do u like it, i hope to fly it this weekend when the weather gets better. havent flown it yet and just got done building it!

Hey Shortman,
I like my SE very much, although I have made some other mods to it. The ARF version has a 5/8" .035 aluminum wing tube, so it was easy for me to move the wing forward 1.5" by building a new wing tube 1.5" ahead of the existing one. I added TWO inches to the rudder, replaced the short stubby gears with a Dubro plastic unit. The plane became more pitch stable and balanced 1" behind the high point at the spars. This was actually too far back. When I went inverted it held inverted without any down elev pressure. I moved the battery pack to behind the tank. I only use a 6oz tank. I get about 7-8 minutes at full throttle, but most flights last 13 minutes because the SE flies very slowly with very little throttle. I just burst the power when I need it. I use flaperons coupled to elevator when I'm horsing around at low speeds. It seems to add 10 inches to the wingspan because it adds a lot of lift. My next mod is to add 1.5" of span to the elevators. This will mean some nice sized counterbalances on the elevators. I use a 13 x 6 APC, but have been experimenting with a 12 x 8 APC. It seems to give more torque and higher prop blast speeds during the hover/torque roll (attempted torque rolls anyway). The 6lbs 3oz weight requires more power than is comfortable in a hover, but it still fun to try. I think if this could be brought in at 5lbs it would be a lot better, but it's a heck of a lot better than most sport planes. With the 13 x 6 prop vertical is unlimited. I can "s" my way up to 1000 feet and still have 40-50mph across the top. What a blast! Good luck with your SE.