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Design => Stunt design => Topic started by: Greg L Bahrman on June 17, 2006, 10:13:03 PM

Title: Adjustble Rudders
Post by: Greg L Bahrman on June 17, 2006, 10:13:03 PM
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Remember when we were kids and I build my Ringmaster. Man that thing had a minimum of 1 inch rudder offset maybe more. So far all my recent planes have had adjustable rudders and thats a good thing because after watching Brett trim a plane, the first thing he did was cut the rudder off and re-glue it close to straight. So I went back and adjusted my rudders close to straight and the planes flew better. So my real question is should I continue to make adjustable rudders or are we advanced enough or knowledgeable enough to be able to say that making an adjustable rudder is a waste of time. Just glue it on your Magnum almost straight and be done with it. Your thoughts please...

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Title: Re: Adjustble Rudders
Post by: Jim Thomerson on June 18, 2006, 10:18:45 AM
I have built a couple of airplanes with wing structure which made adjustable leadouts unpractical.  I made them with adjustable rudders and got them flying pretty good.  Doing an adjustable rudder as an experiment is a good thing just to be able to see what it does for you.  I think the ideal, which I've never done, is both adjustable leadouts and adjustable rudder.
Title: Re: Adjustble Rudders
Post by: Brett Buck on June 18, 2006, 03:31:23 PM
So my real question is should I continue to make adjustable rudders or are we advanced enough or knowledgeable enough to be able to say that making an adjustable rudder is a waste of time. Just glue it on your Magnum almost straight and be done with it. Your thoughts please...



    If I was going to make something unadjustable, I would be more tempted to make the leadouts fixed, rather than the rudder. But that doesn't mean it's a good idea.

     I think the rudder is far more critical. Not so you can dial in more offset to get more line tension, but, to cover building errors and day-to-day variations in the models alignment. You'd be amazed how much the alignment changes from moment to moment through the day.

      Brett
Title: Re: Adjustble Rudders
Post by: Greg L Bahrman on June 18, 2006, 10:49:04 PM
Thanks Jim, Thanks Brett
Title: Re: Adjustble Rudders
Post by: captcurt on June 20, 2006, 08:13:47 AM
It is certainly NOT a trivial exercise to make and install an aerodynamically neutral fin/rudder.  Even if it LOOKS straight, it might not be....and there is always the offset prop wash vector that makes it impossible to pre-determine.

Why not?  its an easy thing to do.