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Conference vmszoo::rc

Title:	Welcome To The Radio Control Conference
Notice:	dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:	VMSSG::FRIEDRICHS

Created:	Tue Jan 13 1987
Last Modified:	Thu Jun 05 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	1706
Total number of notes:	27193

1350.0. "Pivomano project" by MR4DEC::ANKER (Anker Berg-Sonne) Fri Aug 23 1991 14:28

                I'm about to embark on a very interesting project, namely
        building a Dodgson  Designs  Camano  with  a fixed stabilizer, no
        ailerons and with full length camber control/flap.
        
                You may very well  ask  "how does this sucker go up, down
        or around"? Good question..... The answer is WING PIVOTING!
        
                You may then ask "why  would anybody want to do something
        this crazy, and anyway, what's the point of doing this"?
        
                The answer to this is based  on several thesis(is):  
        
                1.  We keep putting lead in  the  noses  of  our  gliders
                because  the  tails  are  heavy.    Why are  they  heavy?
                Because  of  all  the  control stuff, cables, bellcranks,
                rods etc. etc.
        
                2.   Ailerons  are  relatively  inefficient as a meant of
                controlling pitch.   Here  we  have  a  perfectly created
                airfoil  which  we then  keep  ruining  by  changing  the
                trailing edge all the time.   Drag, drag, drag, sink sink
                sink! Adverse yaw, shucks!
        
                So is there a way to  eliminate  all  of  these problems?
        Well, yes there is!  By using  wing  pivoting to control roll and
        for attitude you don't need to stuff the  tail  full of stuff nor
        do you destroy the airfoil shape every time you make a turn.
        
                The  trouble is that you need some strange mixing.    You
        have  separate  servos  in  each  wing  controlling  the angle of
        attack.   When the aileron stick is moved one wing increases  and
        the  other  wing  descreses its angle of attach.  When you jiggle
        the elevator  stick  you  change  the angle of attack in the same
        direction.
        
                I  hear the  poor  naive  sould  yelling  "That's  elevon
        mixing used on flying wings".  "Nay"! I yell, "the elevator servo
        moves the wrong way"!  So all those fancy, preprogrammed computer
        glider radios can't do it.   Well,  I  finally found and bought a
        radio that is capable of mixing for this flight configuration, an
        ACE MicroPRO 8000.  This radio allows arbitrary  mixing  from any
        channel to any other channel, so I'm embarking on the project.
        
                The wings are going to tilt around the wingrod with a pin
        at the leading edge going into a bellcrank thats attached  to the
        pivot servo inside the fuse.  We now have one less servo that the
        standard  ship because two servos do what the two ailerin and the
        one elevator servo did.
        
                The flaps  are  going  to be full width controlled by one
        servo in each  wing.    This  servo  will be used for both camber
        control (launh, reflex) and flap.
        
                The tail will be converted to a T tail with adjustment to
        the incidence done by shims on top of the vertical fin.
        
                The rudder will be controlled by kevlar pull-pull cables.
        
                Its going to be interesting how this project pans out!
        
        Anker

T.R	Title	User	Personal Name	Date	Lines
1350.1		USRCV1::BLUMJ		`Fri Aug 23 1991 16:42`	8
	Sounds like an interesting project. About a year ago Model Aviation did a construction review on a 2 meter pivoting wing slope ship called "ORCA" which is a Harley Michaelis design. It might be worth looking at it if you have not already seen it. Good luck! Regards, Jim
1350.2	Flying wing with servo reverse switch?	KAY::FISHER	Stop and smell the balsa.	`Fri Aug 23 1991 16:58`	36
	> <<< Note 1350.0 by MR4DEC::ANKER "Anker Berg-Sonne" >>> > -< Pivomano project >- ... > The trouble is that you need some strange mixing. You > have separate servos in each wing controlling the angle of > attack. When the aileron stick is moved one wing increases and > the other wing descreses its angle of attach. When you jiggle > the elevator stick you change the angle of attack in the same > direction. > > I hear the poor naive sould yelling "That's elevon > mixing used on flying wings". "Nay"! I yell, "the elevator servo > moves the wrong way"! So all those fancy, preprogrammed computer > glider radios can't do it. Well, I finally found and bought a Sounds like elevaron mixing to me. What am I missing here - when you pull back on the stick you want both wings to pivot backward (trailing edges to go down) just like a V-Tail reversed. When you give left Aileron you want the left wing to pivot forward (trailing edge to come up) and the right wing to pivot backward (trailing edge to come down). Still sounds like elevrons to me. Anyway I'm interested since I have a Pivot Plus in my building queue and a Camano on order. Fyi - Dodgson tried pitcherons on the Pivot proto and said they made the plane too unstable and hard to handle - too many unexpected snap rolls. P.S. Glad to here you got the ACE radio P.S.S. For you glider/computer radio nuts this months RCM has a chart comparing all (most) computer radios including ACE 8000, vision, and JR 347. Check it out. Bye --+-- Kay R. Fisher \| ---------------O--------------- ################################################################################
1350.3	The 8000 is the assembly coder's radio for the nitty gritty	ZENDIA::REITH	Jim Reith DTN 226-6102 - LTN2-1/F02	`Fri Aug 23 1991 17:07`	13
	Well, what did it say, Kay? Which radio did they rate highest? FWIW: The X-347 will do this mixing. I did it inadvertantly. If you use the directions for elevons and then swap the plugs on the servos and reverse both servos, this is what you get. I know, I got it on my Gremlin and it drove me crazy until I found that I had reversed the two servo leads (the instructions tell you where to plug the left and right servos) I've seen the Ace radio and got a LONG discussion of it with Ray at his shop one night. It truely seems to be the programmers radio since you can combine everything imaginable. The 347 has a better interface to the standard combinations but the one-on-one mixing is hidden behind preprogrammed standard mixes. Good luck with it and your project. We'll be watching for yopu in the contests.
1350.4		UPSENG::WALTER		`Fri Aug 23 1991 20:55`	5
	Why bother trimming the horizontal stabilizer for incidence? Won't the "elevator" trim do essentially the same thing? Dave
1350.5	No radio get's first place...	KAY::FISHER	Stop and smell the balsa.	`Mon Aug 26 1991 15:00`	10
	> Well, what did it say, Kay? Which radio did they rate highest? He didn't rate the radios - just make a very detailed chart listing all the features and which radios had them and which didn't. Very informative to see them all side by side. Bye --+-- Kay R. Fisher \| ---------------O--------------- ################################################################################
1350.6	Airtronics MD7 SP works just fine	BZERKR::DUFRESNE	VAXKLR - You make'em, I break'em	`Wed Aug 28 1991 16:11`	9
	And MD7SP has a the mix function you want for this plane. The one to use is the Elevon mix. I have an ORCA on the bench (fuse done, ready to start on wings). This is built like a tank. HAley Michaelis has a updated design wth has ailron and flaps with pitcheron system. Plans appeard in Model Aviation about a year back. md
1350.7	Wing Twist Down-Under	SNOC02::FIELDEN		`Tue Oct 15 1991 01:39`	21
	Anker, Greetings from australia. I built a wing twist/pitch control for a small slope soarer last year. It worked well. Roll authority was as good as regular ailerons but pitch was a bit sluggish but controlable. There was an article in UK RCME some years ago where the builder put sevos inside the wing roots of each hinged wing and he reported similar results to me = pitch slow, roll ok. Used TX mixing. My small sloper had inside fuselage mechanical mixing - bit bulky but it worked ok. How about pitch and roll control with fixed flying surfaces and mobile ballast fore and aft as well as (separately) side to side!!! Keep us informed re progress Rgds Roger
1350.8	Wing Warp - Mind Warp - Etc	KAY::FISHER	If better is possible, good is not enough.	`Tue Oct 15 1991 10:12`	34
	> <<< Note 1350.7 by SNOC02::FIELDEN >>> > -< Wing Twist Down-Under >- ... How about pitch and roll control with fixed flying surfaces and mobile ballast fore and aft as well as (separately) side to side!!! ... Roger - what have you been smoking (reading) :-) Makes the mind wonder doesn't it. Consider this. CG adjustment is constantly fighting trim. If you change the CG a bit you must adjust your trim to compensate. If you have no trim adjustments only move ballast around you have eliminated one of the variables. But... You know how when you fly inverted ailerons are normal and only the elevator is reversed. With a moving ballast control system this would be backwards. Inverted ailerons would be reversed (actually wing ballast movement in this case) and pitch would be normal. Attempting a roll would be interesting! Knife edge flight would be a piece of cake - just add weight to the port wing and leave it there - this should drop the wing and keep it dropped. Now moving the for/aft weight will control the rudder (sort of since there is no rudder). The only functional moving ballast I have ever read about was in relation to compensation for retracts that go for and aft. Bye --+-- Kay R. Fisher \| ---------------O--------------- ################################################################################
1350.9	I will be using camber instead	MR4DEC::ANKER	Anker Berg-Sonne	`Sun Oct 20 1991 14:04`	11
	Re: <<< Note 1350.8 by KAY::FISHER "If better is possible, good is not enough." >>> My idea is to mix in camber control to make the pitch control more sensitive. I have camber control anyway and mixing in camber could have a couple of desirable side effects. To hunt for thermals one would only have to give a bit of down elevator stick and both camber and pitch would be perfect. The same for thermalling, just a bit of up and all the surfaces would be ideal! Anker