Lafayette

Ok, so I am wondering. I am building a kti right now, and I am worried about teh atail section. How offset do you think the horizontal stab can be before the airplane starts banking uncotrollably when airbourne, or poses considerable effort to fly even when trimming is applied?

I think that my left of the horizontal stab imgght end up 2 to 3 mm higher than the right side. Is that alright? Would it pose difficulties in flight is the airplane is a trainer airplane?

Thank you, PLEASE RESPOND, PLEASE..

Lafayete. Thanks a lot.

Bax

My Feedback: (11)

Actually, you can likely have one stabilizer tip higher by 10-15 mm on a .40-size or larger model and not have much trouble flying it. 2-3 mm is actually very little and of almost no consequence.

rmh

There is another problem we se on some of the small electric models
The structure (?) of the tailplanes is sometimes so poorly designed that the covering is the only thing aligning it.
The new user may attempt to tighten the covering - even carefully done, the results oft times are terrible as the heat gun shrinks one side at first , and imparts a more extreme twist.

But as noted above a couple of mm is typically of no consequence
UNLESS the structure is so flimsy that any speed buildup will start it moving.

Top_Gunn

My Feedback: (6)

I have a Kadet Senior, built by somebody else, which has one tip of the stabilizer at least an inch higher than the other. It looks weird, but it doesn't seem to affect the flying at all. On an aerobatic plane, though, a serious imbalance might affect performance more noticeably.

DwightMann

Get it as good as you can, but don't spend too much time on it. If you demand perfection you will never get there. The more time that you spend on it, the more that it will hurt when you crash

combatpigg

My Feedback: (3)

Making sure that the wing isn't twisted ranks a little bit higher than fixing a slight stab tilt. Stab tilt is a trimming tool that some free flighters have used........I'm not sure what for.

rmh

That's tilt ,not twist - It will aid in holding a gentle open gliding circle.

combatpigg

My Feedback: (3)

Thanks Dick, I've only flown free flight a few times......by accident.

rainedave

My Feedback: (1)

Yes, stab tilt will cause a free flight model to bank towards the high tip. Thermals are cylindrical columns of hot, rising air and the goal is to keep your model circling within the thermal (like hawks do).

The reason it is used is because it has little or no effect on the power segment of the flight. Rudder trim is used to control the flight path while the engine is running and stab tilt is used to control the glide. If you used offset rudder to control the glide it would also have a great effect on the powered segment of the flight which you don't want. Free flight consists of three distinct flight segments: the powered segment, the transition to glide and the glide. Each segment uses its own distinct trim functions for control. Rudder trim tabs, inner wing panel wash-in and engine side thrust are used to trim the powered segment. Engine down thrust is used to control the transition. Stab tilt and CG location are used to control the glide. Wing and stab incidence can effect all three segments. It's best not to mess with them on a free flight model.

All that a tilted stab will do (on an r/c trainer) is cause the plane to want to bank a little bit. Opposite aileron trim will fix it.

David