[NSRCA-discussion] the joy of trim
Matthew Frederick
mjfrederick at cox.net
Mon Mar 10 09:14:33 AKDT 2008
I flew Bryan Hebert's composite Shinden yesterday. He has no mix, positive
incidence, and picture perfect downlines.
----- Original Message -----
From: "Wayne Galligan" <wgalligan at att.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, March 10, 2008 9:13 AM
Subject: Re: [NSRCA-discussion] the joy of trim
> If the plane is setup with any positive incidence there will be the
> tendency
> to pull to the canopy on down lines. I have experienced this on all my
> planes once they were set up in all other areas. Doesn't mean there is a
> problem with the airframe. And it doesn't take very much mix to get the
> down line nice and straight.
>
> Wayne
>
> ----- Original Message -----
> From: "Matthew Frederick" <mjfrederick at cox.net>
> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
> Sent: Monday, March 10, 2008 4:36 AM
> Subject: Re: [NSRCA-discussion] the joy of trim
>
>
>> That would be cheating. If you have to overcome the problems of an
>> airframe
>> by using all those conditional mixes, you need a new airframe.
>>
>>
>> ----- Original Message -----
>> From: "James Oddino" <joddino at socal.rr.com>
>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>> 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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>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
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