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Old Mar 01, 2011, 07:35 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
North AL, USA
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Quote:
Originally Posted by Freddie B View Post
Viking did a mod to a KFm wing by adding a piece of depron behind the steps, ending just in front of the ailerons.
Beyond confirming CG, I may give that a shot. I have some 3mm i can use with painters tape - that will introduce little weight.
Thanks for the feedback.
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Old Mar 01, 2011, 07:52 PM
A Day @ a Time - Matt. 6:25-34
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Quote:
Originally Posted by springer View Post
...Went through pretty much what you are going through with my 42, and after adding differential, she will roll into a turn nice and straight without dropping tail or wallowing as long as I'm above about 1/3 throttle...
THX Springer...
Your description of the aileron turn behavior is exactly what my bird is doing! With the wind the way it was, we had to go 70-80% throttle whereas with RET only, we could cruise easily at about 60%. At 60%, she would just keep at altitude and sit in one place during the aileron maiden.
My instructor remarked "whoa, didn't expect that" a few times... I think the bird is doing some goofy stuff the way the wing is setup. I know it isn't the fuse or tail feathers, I maidened her by myself about a year ago with no assistance and was amazed how easy it was to fly it setup as RET. Never had done real stick time either, just a simulator.
I have two servos on the wing, one for each control surface. I could dial in differential, but I have one of the Exceed 2.4ghz systems that doesn't have a lot of advanced features. Eagle34, got yer ears on? Maybe you can pm me your setup info and the config, if I remember right you had a setup for this radio that gave you differential.
Given the information I have already gleaned from the last few postings, I think I'll check the CG again, skip the tip plates, and maybe try the depron cover first just to see how it flies. Some of my club members said we could get some differential by manipulating the control horns, so I'll check in with them on that.
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Old Mar 01, 2011, 08:30 PM
treefinder
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Agree on a recheck of cg, and biasing to nose heavy. You can always fly a noseheavy plane, but a tail heavy one is gonna act wierd. And I'd forgotten but you're right, if servos are on top of wing, then rotating the neutral point of servo arm aft and shortening the rod should do the trick if I remember right.
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Old Mar 01, 2011, 08:34 PM
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http://www.ky-model.com/copterx/CX-CT6A_manual.pdf

Do you have these instructions.? not the best, but I think you should try playing with the "end points" for the channels you have the ailerons on. You can probably set up and down limits on them then save and try.
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Old Mar 01, 2011, 08:39 PM
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play with the up and down limits untill your ailerons look like this.... gee I wonder where this came from??


http://www.rcgroups.com/forums/showp...postcount=2910
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Old Mar 01, 2011, 09:31 PM
A Day @ a Time - Matt. 6:25-34
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Quote:
Originally Posted by wheelspinner20 View Post
http://www.ky-model.com/copterx/CX-CT6A_manual.pdf

Do you have these instructions.? not the best, but I think you should try playing with the "end points" for the channels you have the ailerons on. You can probably set up and down limits on them then save and try.
I'll take a look... I also licensed Digital Radio too, so I can poke around with that. Might be the best thing to do for now...
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Old Mar 01, 2011, 09:33 PM
A Day @ a Time - Matt. 6:25-34
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North AL, USA
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Quote:
Originally Posted by springer View Post
Agree on a recheck of cg, and biasing to nose heavy. You can always fly a noseheavy plane, but a tail heavy one is gonna act wierd. And I'd forgotten but you're right, if servos are on top of wing, then rotating the neutral point of servo arm aft and shortening the rod should do the trick if I remember right.
I thought it was the opposite, you bring it fore, not aft; check out the image in this link:
http://www.modelaircraft.org/mag/ftg...roundup10.html
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Old Mar 01, 2011, 09:37 PM
treefinder
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Here's the geometry. as the link you posted, servo horn neutral point goes aft IF you have servos sitting upright on top of wing. If they are inverted on bottom of wing, then it goes fwd. I should add, both servo horns new neutral points go aft of their original neutral point. Then they move essentially like the single horn would.
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Old Mar 01, 2011, 09:40 PM
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ruff

If I'm not mistaken, that diagram is for a single servo operating both ail surfaces.




Edit: nevermind, springers diagram I see is assuming you are not going to do it in the radio...that makes sense.
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Old Mar 01, 2011, 09:44 PM
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that works for dual servos as well
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Old Mar 01, 2011, 09:47 PM
A Day @ a Time - Matt. 6:25-34
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North AL, USA
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Quote:
Originally Posted by springer View Post
Here's the geometry. as the link you posted, servo horn neutral point goes aft IF you have servos sitting upright on top of wing.
Ahh, my bad, thinking of surface horn, not servo arm. This should be easy to try, I'll run it back 20 or so degrees and see how it looks.
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Old Mar 01, 2011, 10:47 PM
treefinder
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yup, check it out and see how they move.
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Old Mar 02, 2011, 08:34 PM
A Day @ a Time - Matt. 6:25-34
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I'm a bit lazy, how much down (% of top movement) should I start with? 50?
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Old Mar 02, 2011, 10:15 PM
Jack
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It is more a case of setting the up movement to where you want it and just taking what you get for the down. If you reduce the up and also reduces the down.

I tried it on a flying wing once and did not see any noticeable difference in that case. Flying wings don't, as a rule, do very axial rolls. Has to do with the absence of a fuselage and being more pushed than pulled I think.

Jack
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Old Mar 03, 2011, 07:19 AM
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If you have an aileron that won't behave, it may indicate :

1. You have too much slop in your aileron control linkages
2. You have stickiness in your control linkages
3. Your aileron servos do not return to center very well

maybe you can check out the above.

chewy
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