[NSRCA-discussion] the joy of trim
James Oddino
joddino at socal.rr.com
Mon Mar 10 07:14:34 AKDT 2008
I thought Bryan convinced me years ago that stab incidence was
unimportant as long as you could trim the airplane to fly at the
required angle of attack. That would seem to limit the problem to the
angle we call down thrust and the cg position.
Jim O
On Mar 9, 2008, at 11:58 PM, Nat Penton wrote:
> Jim
> I'm ashamed of you. Mixes are just conversation pieices, not to use.
>
> ----- Original Message -----
> From: "James Oddino" <joddino at socal.rr.com>
> To: "NSRCA Mailing List" <nsrca-discussion at lists.f3a.us>
> Sent: Monday, March 10, 2008 12:26 AM
> Subject: Re: [NSRCA-discussion] the joy of trim
>
>
>> 1) Low throttle to down elevator mix. About 2% only at low end.
>> 2) Rudder to Elevator mix.
>>
>> Jim O
>>
>>
>> On Mar 9, 2008, at 12:07 AM, Keith Black wrote:
>>
>>> OK Bryan, I'll take you up on your offer.
>>>
>>> Plane:
>>>
>>> Beryll (you've had experience last year with Brett's)
>>>
>>> Problems:
>>>
>>> 1) Pull to canopy on downline
>>>
>>> 2) Tuck to belly on knife edge.
>>>
>>> (haven't noticed a pull to the canopy on upline, but really didn't
>>> test
>>> that closely)
>>>
>>> History:
>>>
>>> Initial setup incidence was .5+, CG about 175 mm behind leading
>>> edge. First
>>> flights felt very nose heavy, when rolling inverted seemed to need
>>> lots of
>>> down elevator, also the 45 deg up then roll to inverted test dropped
>>> nose
>>> more quickly than I like. Also as noted above it pull to belly on
>>> knife edge
>>> and pulled to canopy on downline.
>>>
>>> To help solve tuck to belly in knife edge I increased the incidence
>>> as much
>>> as I could (without a dremmel) probably a 1.5 to 2 turns. Also moved
>>> CG back
>>> about 3/8" or so to help nose heavy feel. Changes improved nose
>>> heavy feel
>>> and seemed to improve downline pull to canopy a bit, but it needs
>>> further
>>> improvement as it still pulls to canopy in dive. I ended up mixing
>>> out pull
>>> to belly in knife edge as the adjustments didn't help that.
>>>
>>> So what do you suggest? Seems like the move of the CG helped the
>>> inverted
>>> flight and transition to inverted on slow roll. I'm concerned that
>>> increasing the incidence more and moving CG forward may fix belly
>>> tuck in
>>> dive but would lead to nose heavy feel of inverted flight again. I
>>> know can
>>> increase the down elevator (or remove expo) to offset the nose heavy
>>> feel,
>>> but I don't like the transition from upright flight to knife edge to
>>> require
>>> so much top rudder that it throws off the track when at the 1/8
>>> point of the
>>> roll.
>>>
>>> What say you Sensei?
>>>
>>> Thanks,
>>> Keith
>>>
>>> ----- Original Message -----
>>> From: <shinden1 at cox.net>
>>> To: "xvcNSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>> Sent: Saturday, March 08, 2008 10:24 PM
>>> Subject: Re: [NSRCA-discussion] the joy of trim
>>>
>>>
>>>> thanks Lance
>>>> we all know I`m a terrible writer and thats part of my reasoning
>>>> here
>>>> I have great respect for Matt and his abilities he is a great
>>>> modeler and
>>>> designer.
>>>> I am trying to use past experience when helping with these issues
>>>> as a
>>>> guide to how far out of line these things can get because of a
>>>> misunderstanding that leads into a poor fix
>>>> or a modeler who is not up to the task and trys to take the
>>>> shortcut
>>>> ,,,there are no shortcuts
>>>> I would be willing to bet 98% of pattern fliers don`t even know
>>>> what their
>>>> down thust is and have never measured it. 1deg down is a lot.
>>>> and most could not find a baseline to start with as a watermark for
>>>> later
>>>> measurements
>>>> I was trying to point out that it should be a method of fine tuning
>>>> rather
>>>> than using it to steer a wayward airplane into submission.
>>>> The wing is the most important ,powerful and effective way to
>>>> adjust
>>>> flight path ,,, airfoil ,stab placement , engine thrust ,,are way
>>>> down the
>>>> list in importance as seen with a foamy,,
>>>>
>>>> First things first ,,get the wing inc right THEN,, the ac/g ..you
>>>> would be
>>>> surprised at how for off you can fly c/g and get away with it ,,,
>>>> What Matt and I call pulling to the Canopy and what Joe Blow calles
>>>> it i`m
>>>> sure ,, are two different things.{BTW I would bet most of the
>>>> fliers out
>>>> there with differential fix problems ,,are there becuase of an up
>>>> line
>>>> pull,
>>>> usually because your flying a tail heavy airplane } if ou use tail
>>>> weight
>>>> to create a pos angle of attack lots of little problems arise you
>>>> have to
>>>> use inc to creat the lift and C/g to adjust the feel
>>>> earlier I was trying to make the bigger picture nothing against
>>>> what Matt
>>>> was offering ,,,,
>>>>
>>>> I disagree there is more than one way to trim there is only one way
>>>> our accepted outcome is the difference
>>>> I would like to say I`m probably more hard headed than the Next
>>>> guy , so
>>>> I stick to my guns till proven wrong but accept it when I can be
>>>> proven
>>>> wrong,, ,, after designing over 15 pattern airplanes and keeping
>>>> notes
>>>> ,,, my outcome notes all say the same thing in the end ,it never
>>>> changes
>>>> ,,even when I get a bright idea to change or tweak the setup it
>>>> leads me
>>>> back to where I started.
>>>> After watching Arch fly his Black magic in the bumpy 25mph winds in
>>>> Crowly
>>>> La. A smoking performance ,,,I might add
>>>> the BM appeared to be on rails then,,watching my own airplane dance
>>>> around
>>>> I realized something I knew But had ignored ,,,it made me go back
>>>> to the
>>>> notes where I found the answer ,,, it never changed!!
>>>> the BM was a great design Properly trimmed BUT,
>>>> I,, had been trying to adjust upline canopy pull with engine thrust
>>>> and
>>>> tail weight ,,,,I don`t have the Luxury of calling the designer and
>>>> asking
>>>> where to put the C/G and wing Inc ,,,I have to find it <G>
>>>> when I realized it needed more wing inc less tail weight and less
>>>> down
>>>> thrust it reaffirmed my notes and when the next time I flew in
>>>> those
>>>> conditions it proved me right you have to balance all these things
>>>> The airplane flys around the wing ,,,,let the airplane talk to
>>>> you ,,be
>>>> honest in you evaluations accept nothing but absolute perfection it
>>>> is
>>>> attainable
>>>>
>>>> would anyone like to try an onlist diagnosis of their airplane?
>>>> you tell me the Set up ,,they must be very Accurate give me the
>>>> Symptoms
>>>> ,,and I`ll provide the cure
>>>> you tell us what is happening with the input ,,,BEWARE it can be
>>>> tedious
>>>> and it might include using a saw!!<G>
>>>> any takers ??
>>>> Bryan
>>>> sorry to be so longwinded
>>>> ---- Lance Van Nostrand <patterndude at tx.rr.com> wrote:
>>>>> Bryan,
>>>> I have been anticipating your response but now it seems it won't be
>>>> coming
>>>> soon. Maybe we can take this offline. There's no way anyone could
>>>> interpret my response as being argumentative and I know your are
>>>> tough
>>>> enough to take a few pin pricks without flinching. Certainly I
>>>> have my
>>>> own
>>>> experiences and opinions but those are completely set aside. I
>>>> believe
>>>> there are always at least 10 correct answers to any modeling
>>>> question but
>>>> each answer is right within its own context.
>>>>
>>>> In other words, I start from 0-0 and have my trim process advance
>>>> from
>>>> there
>>>> and usually get very good results. I think, if I remember
>>>> correctly your
>>>> old KF article and our live discussions, you start from 1/2 degree
>>>> positive
>>>> inc in wing and stab and advance from there. Since I know your
>>>> path is
>>>> different from mine I am trying to learn from you. this is why I
>>>> question
>>>> and ask for deeper explanation. Maybe it's just not there. The
>>>> answer
>>>> might be "I never tested in a wind tunnel, can't explain why it
>>>> works, but
>>>> it does so just try it and enjoy." But I hate to see you bow out
>>>> when
>>>> someone asks for more details. that makes Krishlan's comment seem
>>>> relevant
>>>> when, knowing how much you help others and contribute to this
>>>> sport, it
>>>> shouldn't be.
>>>>
>>>> --Lance
>>>>
>>>> ----- Original Message -----
>>>> From: <shinden1 at cox.net>
>>>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>>> Sent: Saturday, March 08, 2008 5:32 PM
>>>> Subject: Re: [NSRCA-discussion] the joy of trim
>>>>
>>>>
>>>>> Ok Matt
>>>>> I accept, your probably right ..
>>>>>
>>>>> I will now bow out of the discussion it`s not going anywhere and
>>>>> I`m
>>>>> waiting my time trying to inform, it seems all the people I`ve
>>>>> helped
>>>>> accomplish what I`m preaching have quit the sport or they are
>>>>> scared to
>>>>> write !!
>>>>> I`ll leave you with this ,
>>>>> demand of perfection is different by each persons ability and
>>>>> goals,
>>>>> sometimes we deceive ourselves in thinking we kow it all or
>>>>> we get caught up in out wording every one and talking nonsense ,,
>>>>> then no
>>>>> one gets anything out of the conversation
>>>>> and then, you die of a thousand pin pricks<G>
>>>>> I can remember sharing pos inc setup with Nat on numerous
>>>>> occasions and
>>>>> Nat out worded me and proved me wrong on paper and you know he
>>>>> can ,, in
>>>>> a
>>>>> Popeye Fried chicken House of all places,
>>>>> However I find out years Later he now uses My setup I`m proud <G>
>>>>> ok ,I`ll stop beating a dead horse I know better than to start
>>>>> this
>>>>>
>>>>> carry on
>>>>> Bryan
>>>>>
>>>>> ---- rcmaster199 at aol.com wrote:
>>>>>> Bryan,
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> I respectfully disagree on the upline, full power issue. The
>>>>>> downline is
>>>>>> a totally different trim situation because the vectors involved
>>>>>> are
>>>>>> different
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> MattK
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> -----Original Message-----
>>>>>>
>>>>>> From: Nat Penton
>>>>>>
>>>>>> To: NSRCA Mailing List
>>>>>>
>>>>>> Sent: Fri, 7 Mar 2008 7:16 pm
>>>>>>
>>>>>> Subject: Re: [NSRCA-discussion] the joy of trim
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> I'm thinking, I'm thinking ----- Original Message -----
>>>>>> From:
>>>>>> shinden1 at cox.net> To: "NSRCA Mailing List"
>>>>>> nsrca-discussion at lists.f3a.us> Sent: Friday, March 07, 2008 1:53
>>>>>> PM
>>>>>> Subject: [NSRCA-discussion] the joy of trim > Matt, I refer
>>>>>> back to
>>>>>> my earlier post > thrust is not the issue. > wing inc. will
>>>>>> always
>>>>>> trump thrust,, in power and influence over vertical > lines. >
>>>>>> thrust
>>>>>> is a" very fine tune" issue it should not be used to adjust >
>>>>>> tracking
>>>>>> issues > > jump in Nat ,, why do you not need down thrust on
>>>>>> your
>>>>>> design?? > Bryan > ---- rcmaster199 at aol.com wrote: >> If the
>>>>>> model
>>>>>> pulls to canopy on a�FULL POWER�vertical upline and you >>
>>>>>> reduce
>>>>>> downthrust, the problem will worsen. You need to add downthrust
>>>>>>>>
>>>>>> (about 1 degree initially, and more if needed). I would not mess
>>>>>> with
>>>>>> CG,
>>>>>>>> at least not yet. >> >> >> � >> >> >> Horizontal flight
>>>>>>>> places
>>>>>> quite a load on the wing....the wing must lift >> the load
>>>>>> accordingly.
>>>>>> Vertical flight removes the load therefore whatever >> trim was
>>>>>> found
>>>>>> in horizontal flight will affect the vertical flight. The >>
>>>>>> simplest
>>>>>> fix is downthrust addition for the condition Mike references,
>>>>>>>> but
>>>>>> assumes that the model is close to begin with. >> >> >> �
>>>>>>>>>>>>
>>>>>> Downline flight (NO POWER) is a totally different trim scenario
>>>>>> and may
>>>>>>>> indeed require wing/stab inc adjustment and CG adjustment. >>
>>>>>>>>>>
>>>>>>>>
>>>>>> � >> >> >> It should be understood�that it is an iterative
>>>>>> process to
>>>>>> get "perfect" >> trim. >> >> >> � >> >> >> MattK >>
>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> -----Original Message----- >> >> From: J N
>>>>>> Hiller >> >> To: NSRCA Mailing List >> >> Sent: Fri, 7 Mar
>>>>>> 2008
>>>>>> 11:33
>>>>>> am >> >> Subject: Re: [NSRCA-discussion] YS Questions+more -
>>>>>> Rolls >>
>>>>>>>>>>>>>>>>>>>>>>>>>>>> The airplane may be flying
>>>>>> with positive trim. Try reducing the down >> thrust or move the
>>>>>> CG
>>>>>> back. >> >> >> If it doesnt help put it back. >> >> >> Jim
>>>>>> Hiller
>>>>>>>>>>>> � >> >> >> -----Original Message----- >> >> From:
>>>>>> nsrca-discussion-bounces at lists.nsrca.org >>
>>>>>> [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of
>>>>>> Michael
>>>>>>>> Wickizer >> >> Sent: Friday, March 07, 2008 8:19 AM >> >>
>>>>>>>> To:
>>>>>> NSRCA Mailing List >> >> Subject: Re: [NSRCA-discussion] YS
>>>>>> Questions+more - Rolls >> >> >> � >> >> >> Bryan: >> >>
>>>>>> � >>
>>>>>>>>
>>>>>> I agree that the plane doesn't know which direction it's flying,
>>>>>> but
>>>>>> then
>>>>>>>> why will a plane fly straight and level then pull to the canopy
>>>>>>>> in
>>>>>>>> uplines?� This has been driving Brett and me crazy for over a
>>>>>>>> year.�
>>>>>>>> Admittedly, it a much shorter drive for me:) >> >> � >>
>>>>>>>> >>
>>>>>>>> Mike
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Date: Thu, 6
>>>>>> Mar
>>>>>> 2008 23:13:48 -0500 >> >> > From: shinden1 at cox.net >> >> >
>>>>>> To:
>>>>>> nsrca-discussion at lists.nsrca.org >> >> > Subject: Re:
>>>>>> [NSRCA-discussion] YS Questions+more - Rolls >> >> > >> >> >
>>>>>> Chris
>>>>>> ,,
>>>>>> the airplane does not know it`s flying horizontal or vertical
>>>>>>>>>>>
>>>>>> the wings are still lifting whether up or down that s why we can
>>>>>> use
>>>>>>>>
>>>>>>> the vertical up or down to test this problem , >> >> >
>>>>>>> Bryan >>
>>>>>>>>
>>>>>>> ---- krishlan fitzsimmons homeremodeling2003 at yahoo.com>
>>>>>>> wrote: >>
>>>>>>>>
>>>>>>>> Lance, >> >> > > >> >> > > Just a thought though, if going
>>>>>> straight up, up straight down, aren't >> > > the up and down
>>>>>> ailerons
>>>>>> both inducing equal drag, no lift? I've >> > > often wondered
>>>>>> if our
>>>>>> straight up test is actually a perfect test for >> > > this. It
>>>>>> is for
>>>>>> our up and down lines, but what about our 45's or >> > >
>>>>>> horizontals
>>>>>> where we do indeed have lift on the low aileron and drag >> > >
>>>>>> on the
>>>>>> other? This would create a different condition I'm guessing..
>>>>>>>>>>
>>>>>> Probably small, but still a little different because as I
>>>>>> mention, >>
>>>>>>>
>>>>>>> both create drag on the up or downline.. Still, it's the best
>>>>>>> test we
>>>>>>>>>> have I guess.. >> >> > > >> >> > > Chris >> >> > > >>
>>>>>>>>>>>>
>>>>>>>
>>>>>>> Lance Van Nostrand patterndude at tx.rr.com> wrote: >> >> > >
>>>>>>> This
>>>>>> thread is timely because I've been experimenting with >> > >
>>>>>> differential >> >> > > recently on a new design that seems to
>>>>>> need it.
>>>>>> Never needed it >> > > before on a >> >> > > pattern plane
>>>>>> but now I
>>>>>> might. My test is to fly very high, point the >> > > nose >>
>>>>>>>>>>
>>>>>> directly at the ground and roll pure aileron. Plane should be
>>>>>> axial,
>>>>>>>>
>>>>>>>> but >> >> > > remember that axial is along the vertical CG,
>>>>>>>> which
>>>>>> may not be a line >> > > that >> >> > > pierces the wing LE/
>>>>>> TE. You
>>>>>> need to do it a few times to be sure that >> > > their >> >>
>>>>>>>> is
>>>>>> an axis that everything rotates around and that line is
>>>>>> straight. >> >
>>>>>>> If it >> >> > > wobbles, then we have an issue. Another way to
>>>>>> determine this is to >> > > do >> >> > > unlimited rolls
>>>>>> while
>>>>>> flying
>>>>>> straight up. If the airplane >> > > consistently arcs >> >> >
>>>>>>> off
>>>>>> its vertical line, you have a problem. >> >> > > >> >> > >
>>>>>> Aerodynamics suggests two contributors. One is that the lowered
>>>>>>>>>>
>>>>>> aileron >> >> > > increases the lift of the airfoil and lift
>>>>>> creates
>>>>>> drag so this wing >> > > may >> >> > > pull the plane off
>>>>>> axis. the
>>>>>> other is that the spiral slipstream of >> > > the prop >> >>
>>>>>>>> is
>>>>>> pushing down on the right wing and up on the left so up/right
>>>>>>>>>>
>>>>>> aileron is >> >> > > more effective than up/left and down/left
>>>>>> is more
>>>>>> effective than >> > > down/right. >> >> > > >> >> > > The
>>>>>> overall
>>>>>> effect for most pattern planes is minimal and usually >> > >
>>>>>> ignorable,
>>>>>>>>>>>> but on IMAC style planes these factors can be significant
>>>>>> and
>>>>>> the >> > > resulting >> >> > > differential corrections may
>>>>>> need to
>>>>>> be adjusted with something as >> > > simple as >> >> > > a
>>>>>> prop
>>>>>> change (from 3 blade to 2 for example). >> >> > > >> >> > >
>>>>>> the
>>>>>> correction of course is to start playing with aileron >> > >
>>>>>> differential. >> >> > > Given the contributors I've suggested,
>>>>>> its not
>>>>>> a given which way you >> > > go with >> >> > > the
>>>>>> differential to
>>>>>> correct the problem and the answer might not even >> > > be
>>>>>>>>>>>
>>>>>>>
>>>>>> symmetrical. >> >> > > >> >> > > Note that contributor #1
>>>>>> above will
>>>>>> change if you are flying upright >> > > or >> >> > >
>>>>>> inverted, so it
>>>>>> would seem that a correction for upright flight would >> > >
>>>>>> simply
>>>>>>>>
>>>>>>>>>> exacerbate inverted flight, but contributor #2 is the same
>>>>>>>>>> for
>>>>>> any
>>>>>>>>>> flight >> >> > > mode but is throttle dependent. >> >>
>>>>>>>>>> > >
>>>>>>>>
>>>>>>>>>> --Lance >> >> > > >> >> > > ----- Original Message -----
>>>>>>>>
>>>>>>>>>> From: "Koenig, Tom" >> >> > > To: "NSRCA Mailing List" >>
>>>>>>>>>>>>
>>>>>>>
>>>>>>> Sent: Thursday, March 06, 2008 4:45 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 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: >> >> > > >> To: "NSRCA Mailing List" >> >> > > >>
>>>>>> 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 wrote: >> >> > > >> > >> >> > > >> >
>>>>>> =============
>>>>>>>>>>>>>>> IMO center hinged or top hinged is OK. With top hinge,
>>>>>> to
>>>>>>>>>>>>> achieve >> >> > > > 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" >> >> > > >> > >> >> > > >> >
>>>>>> 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-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-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 >> >>
>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>> Chris >> >> > > >> >> > > >> >> >
>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>> ---------------------------------
>>>>>>>>
>>>>>>>>>> Never miss a thing. Make Yahoo your homepage. >> >> >
>>>>>> _______________________________________________ >> >> >
>>>>>> 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-
>>>>>> 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-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-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-discussion mailing list
>> NSRCA-discussion at lists.nsrca.org
>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
>
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