[NSRCA-discussion] YS Questions+more - Rolls

Thu Mar 6 17:46:20 AKST 2008

Geez.....It's GOLF all over again....Analysis paralysis (bg)


?


MattK


-----Original Message-----

From: Koenig, Tom 

To: NSRCA Mailing List 

Sent: Thu, 6 Mar 2008 5:45 pm

Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls


My head is spinning!!! The more I think about this, the more questions I  have.........rather than answers!    Maybe the contra rotating prop set up on a Voodoo X( Nat??) maybe the  answer??    I still 'feel', that the best rolls I get are with a 0 differential set  up-BUT- somehow I 'drive' that wing to 0 ( or should that be some sort  of equilibrium??) during the rolls. Certainly in my case, it seems to be  Pilot dependant!!!  I'm starting to think that my rudder control has turned to the  proverbial trying to micro analyse what's happening!    Tom    -----Original Message-----  From: nsrca-discussion-bounces at lists.nsrca.org  [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of  shinden1 at cox.net  Sent: Friday, 7 March 2008 9:15 AM  To: NSRCA Mailing List  Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls    what happens on a 4piont?  Bryan  ---- Del Rykert drykert2 at rochester.rr.com> wrote:   > The general consensus has been that the faster moving molecules over  the top surface don't require as big as a deflection as the aileron that  deflects towards the bottom of the plane. What one tries to achieve is  the plane tracks as purely straight on a string as possible while one  rolls both directions without introducing any yaw.   >    >     Del     >   > ----- Original Message -----  > From: glmiller3 at suddenlink.net>  > To: "NSRCA Mailing List" nsrca-discussion at lists.nsrca.org>  > Sent: Thursday, March 06, 2008 2:49 PM  > Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls  >   >   > > Nat and all you other aerodynamicists,  > >   > > I thought that the rational for "aileron differential" was that  upward deflection causes more drag than downward deflection so to  equalize drag and prevent yaw with aileron deflection, aileron  differential is needed.  It seems that you guys are now saying that  ain't so.  Please elaborate.  > >   > > George  > >   > > ---- Nat Penton natpenton at centurytel.net> wrote:   > >   > > =============  > > IMO center hinged or top hinged is OK. With top hinge, to ac
hieve  equal vertical travel of the trailing edge requires different angular  travel, up vs down. The objective is zero aerodynamic differential.  > >   > > Ron I don't think a fairing would prevent separation but, how are  you able to fair the gap using the top hinge ?            Nat  > >  ----- Original Message -----  > >  From: ronlock at comcast.net  > >  To: NSRCA Mailing List  > >  Sent: Thursday, March 06, 2008 7:20 AM  > >  Subject: Re: [NSRCA-discussion] YS Questions+more - Rolls  > >   > >   > >  And while your at it, I'd appreciate some discussion of the impact  of the top hinge system as seen on Viavat, and Prestige birds -     (top  hinged, with fairing that eliminates the gap at deflection)  > >   > >  Thanks, Ron Lockhart  > >   > >    -------------- Original message --------------   > >    From: vicenterc at comcast.net  > >   > >    Nat,  > >   > >    Could you explain why the differential should be different for  non-center hinged?  I understand that the mechanical configuration of  non-center hinged requires differential to obtain same travel in both  directions.  However, the travel up and down should be close to equal.    > >   > >    Thanks,  > >   > >    --  > >    Vicente "Vince" Bortone  > >   > >      -------------- Original message --------------   > >      From: "Nat Penton" natpenton at centurytel.net>  > >   > >      Tom  > >      It's just something that is peculiar to the Southern  Hemisphere.  > >   > >      Changing wing incidence will not help. Unless things are really  screwed up , at our roll rates, centrifugal forces are too low to  cause a problem. You want zero differential, aero speaking ( same  up/down if center hinged ).  > >   > >      I find the best check is the fast half-roll in the vertical up.  Regards     Nat  > >        ----- Original Message -----   > >        From: Koenig, Tom   > >        To: NSRCA Mailing List   > >        Sent: Wednesday, March 05, 2008 7:24 PM  > >        Subject: Re: [NSRCA-discussion] YS Questions+more  > >   > >   > >        Hi Troy!  > >   > > 
       Thanks for the info. I thought you would be toiling away on  the next developmental stage of these engines!!  > >   > >        Hopefully soon, I can find the time to get flying again. I am  looking forward to running this little beast. I am still a little  concerned in keeping it quiet though.  > >   > >        Four blade props? I have some of the 18.1 x 12 two bladers  but I just cant see how I'll shut the thing up with these paint  stirrers??  > >   > >        Also-one more question to any of you out there in pattern  land.  > >   > >        I have struggled with aileron differential for years. I am  just not happy with the rolls. I have tried various design fixes-but  about the only one that seems to work is to get the wing back to 0-0 (  which can be achieved by a few ways, design, mix or thumbs) Differential  itself does not seem to work if the wing is POA ( well...it works for  half the roll !)  > >        Another black magic fix appears to be to run parallel  ailerons-but this only 'sorta' seems to fix it. I like the feel of  equal% chord ailerons however.  > >   > >        I am frustrated with it-I like my planes to roll as if they  had a string up its ...........well you know!  > >   > >        OK-any 'secrets' I need to know??? Very good elevator work   > > fixes it ( hence my 0-0 comment)  > >   > >        Tom  > >   > >   > > --------------------------------------------------------------------  > > ----  > >   > >   > >        _______________________________________________  > >        NSRCA-discussion mailing list  > >        NSRCA-discussion at lists.nsrca.org  > >        http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  > >   > >   > > --------------------------------------------------------------------  > > ----------  > >   > >   > >  _______________________________________________  > >  NSRCA-discussion mailing list  > >  NSRCA-discussion at lists.nsrca.org  > >  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  > > _______________________________________________  > > NSRCA-dis
cussion mailing list  > > NSRCA-discussion at lists.nsrca.org  > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  > >    _______________________________________________  NSRCA-discussion mailing list  NSRCA-discussion at lists.nsrca.org  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  _______________________________________________  NSRCA-discussion mailing list  NSRCA-discussion at lists.nsrca.org  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion  

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