Elevator problem...
 

Hello,

I have a question regarding my Great Planes Cessna 182 Skylane. Ever since construction I have been puzzled over why my elevators have never been 100% accurate on leveling. Refer to the image showing the rear of my plane. (Remember, that the left elevator is exactly level, both in control calibration and in the area of section B which is only shown on the right elevator)

Section A, where the tips of the elevators line up is always slightly off (approximately 3mm) when I line where section B is marked. However, looking from the front of the plane, to the elevators, it seems like the left elevator is slightly higher, on a horistontal axis. Also, when the tips of the elevators are 100% level, section B on the right elevator is 3mm higher...

This 'problem' perhaps seems to be very small, however, I'm just making sure everything is OK for it's first flight. Do you have any suggestions? Will this 3mm difference ruin flying performance and possibly lead to a crash, or will sufficient aileron trimming counter balance the inaccuracy ..if so, what is a recommended aileron deflection/inflection on takeoff?

Any help would go a long way.



Cheers,
Riccardo

RE: Elevator problem...
 

the image:

RE: Elevator problem...
 

Sorry about this; i used the wrong file format. Here is the JPEG version

RE: Elevator problem...
 

HI RICCARDO17! I can't see the pictures, but are the elevator halves controlled by a split push rod, or seperate servos? You need to find perfectly matching servos if you are using 2. If you have any binding in the hinges, or a weakly built control surface , you will have a problem. But in practice, if everything is sound and hooked up correctly you might not win any pattern contests, but slight deviations in control deflection at typical sport flyer speed shouldn't cause a problem. If you grab the elevator and push against the push rod,[most designs are push for down, pull for up] the elevators shouldn't move. Same goes when you pull on them. Don't do this test to the point of damaging the servos, but you want to be sure that this question is answered in YOUR head before you fly.

RE: Elevator problem...
 

Hello Combatpigg,

I've tried every file format that RCU can take, neither of them have loaded my photo. I can e-mail the photos to you if need be. If possible, try to comprehend what the problem is.

OK, the elevator halves are joined using one servo with steel push rods. I've modified the push rod holders using obechi ply so there is no 'play' in control movement of the elevators.

I'm not interested about placing my Cessna 182 in Pattern Contests, so there is no concern there. The only concern is the 3 mm that the elevators are off.

Thanks for your reply and consideration,

Riccardo

RE: Elevator problem...
 

HI RICCARDO17! Can you grab the elevator halves near the middle and give them a twist to even them out? Or are you saying that one of the elevators is warped slightly?

RE: Elevator problem...
 

Hello,

Upon close inspection, the right elevator's 3rd hinge slot has been cut approx. .5mm higher than the other two, causing the calibration to warp, i think this is where the problem lies...



RT

RE: Elevator problem...
 

GOOD WORK RICCARDO! Boy are YOU PICKY! You will have a great future in PATTERN COMPETITION if you keep iy up!

RE: Elevator problem...
 

A good flyer in our club took 1st place in the club novice pattern competition flying the Cessna. It's quite capable in the right hands.