[NSRCA-discussion] the joy of trim
rcmaster199 at aol.com
rcmaster199 at aol.com
Mon Mar 10 19:21:20 AKDT 2008
Nat,
The beauty is that you may have. It's been so long that I don' remember if it was original or you told me about it (vbg)
Matt
-----Original Message-----
From: Nat Penton
To: NSRCA Mailing List
Sent: Mon, 10 Mar 2008 6:16 pm
Subject: Re: [NSRCA-discussion] the joy of trim
Now why didn't I think of that !
----- Original Message -----
From: rcmaster199 at aol.com
To: nsrca-discussion at lists.f3a.us ; nsrca-discussion at lists.f3a.us
Sent: Monday, March 10, 2008 5:02 PM
Subject: Re: [NSRCA-discussion] the joy of trim
Nat, Keith, et al,
I've used a simple protractor tool for many years to measure this angle......anyone can build it to easily determine downthrust relative to wing. I may have talked about it in one of my KFactor columns years ago, I don't remember.
It's built from a 1/2" square aluminum bar, with a prop shaft hole drilled into it on one end. I scribe a center line lengthwise on the most convenient adjacent side to the hole, then scribe degree marks about 6" away from the center of the shaft hole. I hang a weighted thread on that side, on the center line, then install the bar onto the prop shaft and secure it with the propnut. With wing level, the weighted thread will reach equilibrium at the engine's vertical thrust line (either down, up or neutral). And there you have it....the engine's precise vertical thrustline relative to a level wing
Matt
-----Original Message-----
From: Nat Penton natpenton at centurytel.net>
To: NSRCA Mailing List nsrca-discussion at lists.f3a.us>
Sent: Mon, 10 Mar 2008 4:32 pm
Subject: Re: [NSRCA-discussion] the joy of trim
Keith Both problems indicate too much downthrust relative to the wing setting. If you reduce the wing incidence it will go to the belly harder in KE. We need an accurate measure of the T/L, relative to the wing, for confirmation. Nat ----- Original Message ----- From: "Keith Black" tkeithblack at gmail.com> To: "NSRCA Mailing List" nsrca-discussion at lists.f3a.us> Sent: Monday, March 10, 2008 12:24 PM Subject: Re: [NSRCA-discussion] the joy of trim > Nat, I asked around to try and determine this and was told that the > horizontal canopy seam (flat part when canopy is removed) should be used > to > determine the thrust line. Other than that it wasn't specified. The ship > came with no directions other than some hardware recommendations from Troy > Newman. > > Keith > > > ----- Original Message ----- > From: "Nat Penton" natpenton at centurytel.net> > To: "NSRCA Mailing List" nsrca-discussion at lists.f3a.us> > Sent: Sunday, March 09, 2008 7:17 PM > Subject: Re: [NSRCA-discussion] the joy of trim > > >> Keith >> Where is the thrustline ?? Nat >> >> ----- Original Message ----- >> From: "Keith Black" tkeithblack at gmail.com> >> To: "NSRCA Mailing List" nsrca-discussion at lists.f3a.us> >> Sent: Sunday, March 09, 2008 3:07 AM >> Subject: Re: [NSRCA-discussion] the joy of trim >> >> >>> 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 >>>> 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!! >>>> 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 >>>>> 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 >>>>> 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 > > _______________________________________________ > 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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