RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Questions and Answers (https://www.rcuniverse.com/forum/questions-answers-154/)
-   -   too much trimming for a showtime. (https://www.rcuniverse.com/forum/questions-answers-154/7412608-too-much-trimming-showtime.html)

Stupermario 04-24-2008 12:38 AM

too much trimming for a showtime.
 
Just curious as to what the issue is. Showtime 50 with a Satio .82 on it. For some reason if I level out the trim to neutral and fly, it rolls really hard to the left. Once trimmed out with tons of right airleron it flys great. On inspecting the trim once on the ground, it just seems way too much trim on the surfaces. The left airleron is down about 4-5mm. Any ideas with out adding weight to the right wing?

I have checked lateral balance, if wings or airlerons are warped. Everything checks out fine.

BillyGoat 04-24-2008 06:25 AM

RE: too much trimming for a showtime.
 
Have you checked incidence of each wing panel to make sure they are equal?

Also look at the elevator. Uneven elevators halves can cause rolling too.

Stupermario 04-24-2008 07:14 AM

RE: too much trimming for a showtime.
 
actually elevator halves are dead on. As for incedince... I am unsure what you mean. Please explain? Thanks!

BillyGoat 04-24-2008 07:37 AM

RE: too much trimming for a showtime.
 
Incidence is the angle between the wing's chord and the longitudinal axis of an aircraft.

Not sure about the Showtime 50 but the 90 is supposed to be zero degrees. As I found on my 90, it is quite possiable one wing panel is more positive than the other. To check this you will need an incidence meter.


Stupermario 04-24-2008 07:43 AM

RE: too much trimming for a showtime.
 
Gotcha...I will see if one of the older Gents at my Club have one. I'll post updates to this thread when I find out....if I find out.

Jburry 04-24-2008 01:49 PM

RE: too much trimming for a showtime.
 
Wing incidence is the angle the wing is at with respect to the fuselage. Both wings must be the same. You don't need an incidence meter to be sure they're both the same, just a critical eye.

Also check that the wings aren't twisted. THat much aileron is not likely from lateral imbalance, it's from something aerodynamic.

Stand about 10 feet directly in front of your plane. the propshaft and tail fin should appear to be directly in line. Now move your head straight up or down until the top or bottom surface of the wings is parallel to your line of sight. Do both wings seem to be at exactly the same angle to your line of site? Does the root surface disappear before the tip or vice versa on one wing or the other? Does the surface of one entire wing disappear before the other as you move up and down?

If one whole wing seems different from the other, adjust it however you must until it's correct. If one wing seems twisted, you can correct a minor twist by twisting the wing the opposite way, holding it there, and using a heat gun or iron to re-shrink the covering to hold it. I wrap one end of the wing in a towel and pinch it in a dresser drawer while twisting with my left hand, and ironing/gunning with my right. This fix is usually permanant, but it bears checking at least seasonally to verify that it stays.

Good luck,

J

jetmech05 04-25-2008 05:36 AM

RE: too much trimming for a showtime.
 
what about balance? laterial balance...not CG which is balance for and aft but laterail balance which is left and right....to check this tie a string around the upper rudder hinge, the other end to the prop shaft with enough slack that you can pick up your plane like using a handle....Does the plane always fall off to the side with the aileron down? If so counter weight the light wing as close to the CG line as possible.....

Stupermario 04-25-2008 05:45 AM

RE: too much trimming for a showtime.
 
Yes... Lateral balancing was already done. Balanced with actually a very slight heavier right wing. Which is odd because the plane rolls very hard to the left.

I made a few flights with it yesterday, and intend on it today as well. I will try to post some video tonight.


All times are GMT -8. The time now is 01:50 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.