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RE: 50c... - 6/3/2008 6:29:36 PM   
catfish2


 

Posts: 68
Joined: 3/4/2003
From: Tyler, TX, USA
Status: offline 		For those who are reporting needing aileron trim, I would suggest checking the incidence of the elevator halfves. I have not noticed any need for aileron trim on my Suk, but I think I remember finding the elevators off just a bit from side to side during assembly. If you find both sides true, you could still adjust one side of the elevator to reduce the amount of aileron trim you are currently using. Just a thought and an easy fix.

(in reply to aaxiss)
       Post #: 1101

RE: 50... - 6/4/2008 12:40:17 AM   
LeeHunt


 

Posts: 185
Joined: 2/2/2006
From: Katherine, AUSTRALIA
Status: offline 		Thanks for that Catfish2, I had been hoping someone would come up with a suggestion as to what could be wrong and a possible fix, with the ailerons and true to this thread someone has.
Now all I have to do is figure out how to check the incidence of the elevators oh well back to my books!!!!! LOL
Lee
Ps If you are using Extreme link 2.4ghz be very very careful, I have now had three separate failures and have changed to the JR spectrum module set up and have three recievers fitted to the plane!!!
Lost my last 10 channel on the workbench???? whew.

(in reply to catfish2)
       Post #: 1102

RE: 50... - 6/4/2008 1:30:01 AM   
rctom



Posts: 5206
Joined: 5/8/2002
From: Flower Mound (near Dallas), TX, USA
Status: offline 		Keep in mind that prop driven airplanes are not perfectly symmetrical. The air blast from the prop is swirling off the prop, rising on the left side and falling on the right. Then there is gyroscopic precession and the asymmetry of the prop blades' thrust as they rotate. It's not a perfect world, that's why we have trims and firewall thrust angles and the like.

TF

(in reply to LeeHunt)
       Post #: 1103

RE: 50... - 6/4/2008 8:36:16 AM   
aaxiss



Posts: 164
Joined: 12/18/2006
From: Orange, CA, USA
Status: offline 		I found that my elevator halves were a tad bit off also, in the direction causing more aileron trim . matching the elevators allowed me to remove a bit of the trim in the ailerons, now it's about what I was expecting..... 2 clicks right. Didn't bother with incidence as I am just a sport flier learning a bit of 3d . Plane holds well in both up and down lines hands off, inverted with just the slightest up and snaps like a flying monkey


I have like 4 other planes that I will probably never fly again due to this plane being so much fun.



_____________________________

Don
If there is a 40% plane out there drawing 42 amps it's because it has an on-board welder.

(in reply to rctom)
       Post #: 1104

RE: 50... - 6/4/2008 1:08:31 PM   
darkwarder


 

Posts: 28
Joined: 10/19/2007
From: Milford, OH, USA
Status: offline 		I second that. I only needed 2 clicks of right aileron. As with Don, I mainly sport fly, haven't tried 3D yet with this plane. It flies great at this point. So rather than take a chance screwing something up, I'll leave the incidence alone. Awesome of you to have an answer to this Catfish2. This thread has been invaluable!

(in reply to aaxiss)
       Post #: 1105

RE: 50... - 6/4/2008 11:06:10 PM   
LeeHunt


 

Posts: 185
Joined: 2/2/2006
From: Katherine, AUSTRALIA
Status: offline 		Howdy
Started to look into the incidence thing last night and thought maybe I'am playing around with things to much?????, to take on board what Tom has said and you others prhaps I should leave well alone. The old story " if its not broke don't fix it". Still love flying this machine around, trying to get it to flat spin!!!! nearly got it. Mind you I think Iam a slow learner.
Hey what would happen if you miss matched the elevatots to half compensate for the ailerons, there is less of the elevators, so less drag. Yes No Stupid????? thoughts.
Lee

(in reply to darkwarder)
       Post #: 1106

RE: 50... - 6/5/2008 1:42:45 AM   
Ruski31


 

Posts: 34
Joined: 1/27/2008
From: west babylon, NY, USA
Status: offline 		Lee if you offset the elevators to compensate for the ailerons your loops would look like corkscrews. Most of the differences in the aileron trims is due to some slight warpage in the ailerons themselves, mine have some bows, combine that with P-facter from a big prop and a little lateral balance issue and it can turn into all night chase. If it's close trim it, fly it and after you crash it maybe the next one will be better.....just kiddin'.

(in reply to LeeHunt)
       Post #: 1107

RE: 50... - 6/5/2008 2:50:10 AM   
LeeHunt


 

Posts: 185
Joined: 2/2/2006
From: Katherine, AUSTRALIA
Status: offline 		Ruski31, yeah Iam hearing you, thanks for the info, probably had I thought that through I would never have written it LOL.
Ill just keep flying it till it turns back into a kit!!!!
Lee

(in reply to Ruski31)
       Post #: 1108

RE: 50... - 6/5/2008 6:49:03 PM   
catfish2


 

Posts: 68
Joined: 3/4/2003
From: Tyler, TX, USA
Status: offline 		Just to clarify, I was refering to adjusting the stabilizer (fixed) side of the elevator, not the elevator control surfaces. This could be used to help with the trim issue and would have no particular impact on loop straightness.

(in reply to Ruski31)
       Post #: 1109

RE: 50... - 6/5/2008 9:23:59 PM   
aaxiss



Posts: 164
Joined: 12/18/2006
From: Orange, CA, USA
Status: offline 		Yea, I was trying to clarify that when I went back and looked my elevator halves ( movable parts ) were not matched and part of my need for what I thought was a suspect amount of right Aileron trim was a result of the elevators not being matched. But as to your post yes I agree if you want to have a very straight flying plane through all attitudes than you must insure that all incidence angles are correct. This is definitely a must for anyone flying any type of precision competition or even 3d for that matter. That said, it's probably something the sport pilot doesn't really need to worry about unless the manufacturer has really screwed the pooch during the building process. This being my first large scale plane I am really happy with it, it is perfect?, probably not but I can't tell and I am happy with the way it flies and I think that is what matters . Heck, Ill probably do something dumb like run over it with my wheelchair before I get 25% of the planes serviceable life out of it lol

So basically check all the surfaces, here is a small list of surface and linkage related items to look at that may help you to remove a bit of trim that might have been used to compensate for a problem somewhere else.

Do they line up with each other at nutral?.
Do they work in unison through their range of travel.
Do they have the same range of travel?
Is your linkage geometry the same on both sides?
Are your servos' working at the same speed and centering correctly?
Do the control surfaces move freely without binding or applying pressure.

Minus any aileron differential added if you set up your plane this way I would imagine that is the best you can do other than playing with thrust angles and incidence. I may have missed some things but these are the things I looked at when I was trying to figure out why I had so much aileron trim.

_____________________________

Don
If there is a 40% plane out there drawing 42 amps it's because it has an on-board welder.

(in reply to catfish2)
       Post #: 1110

RE: 50... - 6/5/2008 10:39:38 PM   
Ruski31


 

Posts: 34
Joined: 1/27/2008
From: west babylon, NY, USA
Status: offline 		Yeah Catfish I agree the horizontal stab should be checked to make sure both halves have identical incidence and kept that way, but Lee wanted to offset his elevators, big mistake. Aaxiss has a pretty good list above. Most important is do they line up evenly at neutral and at full deflection, that will incorporate everything on the list and then some.

(in reply to aaxiss)
       Post #: 1111

RE: 50... - 6/5/2008 11:02:00 PM   
LeeHunt


 

Posts: 185
Joined: 2/2/2006
From: Katherine, AUSTRALIA
Status: offline 		Ok hang on a bit,pls correct me if iam wrong, I wanted to adjust the elavators "the moveable parts" not the Horizontal stab. Is this still a big mistake. By the way what is the horizontal stab incidence suppossed to be, and what about the wings ( I suppose I just gota play)
Lee

(in reply to Ruski31)
       Post #: 1112

RE: 50... - 6/5/2008 11:05:55 PM   
roboto65



Posts: 194
Joined: 10/27/2004
From: Conroe, TX, USA
Status: offline 		Wing incidence and stabs should be 0 degrees !

_____________________________

It''s a temporary fix unless it works at which point it becomes permanent!!!

(in reply to LeeHunt)
       Post #: 1113

RE: 50... - 6/5/2008 11:29:56 PM   
LeeHunt


 

Posts: 185
Joined: 2/2/2006
From: Katherine, AUSTRALIA
Status: offline 		Ta Roboto65, along with axxiss,catfish2 and Ruski65. Will check all this info out and see if it flys any better, after all you have to muck around with something, is this not a mans perogative?????
Lee LOL

(in reply to roboto65)