Lots of rudder offset will cause both things.
(swing a rock on the end of a string both fast and slow to demonstrate).
Ted
I must say Shultzie was twirling some mighty fine rocks "back in the day" but he was younger then.Thanks Les..
(He had some great stunt ships too)
In every bunch there has to be someone to descent lol.."descent"
I apologize, I just noticed that I was logged in with my fathers account. The purpose of my post is to incite a discussion about the true dynamic function of the rudder/ vert. stab on a control line plane. General rules do little to increase understanding and are often full of misinformation. This is only my theory of rudder function. I would love to hear some feedback considering this issue in order to properly answer this fellows question.
Got to wonder about the "Al Rabe Rudder!" It must have some effect during maneuvers.Al built semi-scale stunters, which means dihedral, which means yet another set of factors affecting how the plane flies.
Got to wonder about the "Al Rabe Rudder!" It must have some effect during maneuvers.
Brett, I appreciate your reply and I apologize for rehashing a topic that has been discussed before; however, Few new building or design topics can really be introduced to a sport that is as old as CL. I believe that I understand your comment on instability and have a possible solution or at least thought experiment. When an aircraft is over head the angle of attack of the fuselage is acting as an airfoil. The wing and hor. stab/ elevator are acting like a giant rudder. The airplane is also at its most vulnerable in this position. The rudder being at the correct angle will provide stability at this point. A straight rudder will be attempting to lessen yaw and in affect reducing lift. tip weight acts as a centrifugal force to exponentially increase yaw, The lead out angle also provides yaw, as does the engine weight. So in this dynamic view one has two forces providing exponential yaw and the rudder and leadout angle are in effect attempting to limit the yaw to a specific angle. If an airplane is as unstable as the one you suggested there is obviously something amiss I would suggest lessening tip weight or possibly reducing lead-out angle. The fuselage, when it is acting as an airfoil, (over head) requires a specific amount of AOA to produce the correct lift this is the angle that should determine the rudder/ vert stab angle.
Al built semi-scale stunters, which means dihedral, which means yet another set of factors affecting how the plane flies.
I suspect that the rudder was there because the dihedral interacted with the flight path in ways that I am not smart enough to figure out at 11:15 in the morning, and that the rudder made things better -- or at least convinced Al that they were better.
I don't believe this (centrifugal force -- Tim) accounts for the planes ability to stay aloft when flying over head.
Sometimes I find it difficult to write specifically what I am referring to. The rudder in an overhead manueuver will not provide more yaw than the degrees in which it is set if the rudder has 4 degrees of offset it will attempt to maintain a 4 degree yaw. I also do not see why this creates loose lines.
Thanks Time, I think this is the breakdown In communication, Excessive rudder or yaw is bad for sure but what about the right amount of yaw. The original poster had 1" of offset that is obviously way to much; however, putting the rudder on straight is not right either. Every plane is going to require a certain amount of yaw to maintain its lines, this is why adjustable leadouts have become so popular. My point is that once you have found this position the rudder should match the proper yaw angle of the plane.
I am probably wrong about this lol but I am of the assumption that the lead-out angle should set the yaw angle not limit it. Or at least that is how my pea brain works. Not having enough leadout angle makes the thing rock about its vertical axis while maintaining level flight. Too much leadout angle would slow the plane down and drag the lines. All of these adjustments should be made together in order to have a balanced plane. The leadouts, weight box, rudder, tail weight, engine thrust and weight, all need to work for ya. Taking any one of these adjustments to the extreme should cause a mishandling plane.
Take it to the bank that whatever he (Brett Buck) suggests is worthy of any stunt flier's attention and should probably be the first rather than the last step taken when trimming a stunt ship for optimum performance.
Considering that we always flight in a circle, I've wondered if we might even consider a little inboard rudder, to right the ship on its path, reduce its yaw.. Is that a nutso notion?
(snip)
Considering that we always flight in a circle, I've wondered if we might even consider a little inboard rudder, to right the ship on its path, reduce its yaw.. Is that a nutso notion? ;->
L.
"Skill to do comes of doing." -Ralph Waldo Emerson
Hi Larry (and all),
For about two years Aaron flew his Satona with rudder inset. This wasn't noticed until Randy saw it one day at a contest. He said the rudder is pointing "in". After looking hard I saw it. We fixed it and he flew it that way until its unfortunate bout with anti gravity, or maybe it was a black hole........... (I have never had it explained as to why a model will simply drop out of flight in a milisecond with nothing broke and no control applied..... ??? )
BIG Bear
RNMM/AMM
"
...essentially washing off or away what forward movement of air was present over the wing.
Early years after the city moved the circle to a hole.
Hi Randy,
You were there but didn't see the actual mishap. He had done the first loop of the clover and was at the bottom of the second loop when the plane just dropped 5 feet with no evident problem. He had flown over the correct distance so that he wasn't overlapping the loops. I can't see it being wake turbulence. ???
Bill
Hi Randy,
You were there but didn't see the actual mishap. He had done the first loop of the clover and was at the bottom of the second loop when the plane just dropped 5 feet with no evident problem. He had flown over the correct distance so that he wasn't overlapping the loops. I can't see it being wake turbulence. ???
Bill
Hi Bill
What I said,or meant was that the turbulence can and does cause this, and with the strong swirling winds at that place it could have very easily been turbulance, either caused by the winds coming over/under/around the thick bushes/trees. The winds like this can also move wake turbulence around quite fast for a slow developing manouver. One thing I do know is it didn't happen from fixing the inset on the rudder. Sometime stuff happens :-(
Regards
Randy
Thanks, Randy. I didn't mean that you don't know what I was talking about just that you WERE there and might could give the response you just did. It explains the phenomenon as well as any I have heard. And true, fixing the rudder definitely had NOTHING to do with it! LL~ LL~ LL~ (never meant to imply that!) It was amazing that the model flew as well as it did with the inset. Shows it is a good design!
Hopefully Aaron will fix the plane, it was a good flying model and the repairs are not that difficult. Fixing or replacing the stab, and the top of the rudder/fin and nose. Not a lot of work to do to get it back to flying status. At least all the engine needed was a bearing!
Thanks
Bill
What site is that? I didn't notice.
The MCLS site in Huntersville, NC
It can really be horrible at times. I actually read my AMA number on the outboard wing for about a 1/4 lap flying level. Just popped up into a knife edge......