[NSRCA-discussion] the joy of trimming , left rudder tuck downline pulls

vicenterc at comcast.net vicenterc at comcast.net
Tue Mar 11 11:42:16 AKDT 2008


I wonder how many are looking for the e-mail tonight.  For sure I am one of them.  Triangulation Method,  that sound interesting.

Thanks,

--
Vicente "Vince" Bortone

-------------- Original message -------------- 
From: <shinden1 at cox.net> 

> Don I will have a complete response tonight 
> along with the" Hebert traingulation method" for perfect trimming, 
> I know it gets confusing sometimes but I`ll try to explain it a little better 
> tonight 
> Bryan 
> 
> ---- Don Ramsey wrote: 
> > I'm with Jim in not understand the reason some of the incidence changes 
> > work. Consider increasing the incidence for adjusting the push to the belly 
> > in knife edge. My reasoning would be; increase the incidence, put in some 
> > down elevator to fly straight and level. Roll to knife edge and the model 
> > would then push to the belly more severely. What am I missing? 
> > 
> > Don 
> > 
> > -----Original Message----- 
> > From: nsrca-discussion-bounces at lists.nsrca.org 
> > [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of James Oddino 
> > Sent: Tuesday, March 11, 2008 10:59 AM 
> > To: NSRCA Mailing List 
> > Subject: Re: [NSRCA-discussion] the joy of trimming , left rudder tuck 
> > downline pulls 
> > 
> > Bryan, 
> > 
> > I'm trying to figure out how increasing the wing incidence, I assume 
> > with respect to the fuselage, will get rid of a pull to the canopy on 
> > a vertical downline. Is it because you need to crank in some down 
> > trim to make it fly level? Or is it because the tail flies higher in 
> > level flight and the higher vertical cg creates a couple pushing the 
> > nose down during the vertical downline? 
> > 
> > I assume that if one could achieve a good vertical downline with power 
> > off, he could then adjust the thrust to get a good vertical upline? 
> > It would seem that the thrust is part of what made it fly level and 
> > you would get into an endless loop chasing things around. What is the 
> > sequence for getting what you want? 
> > 
> > I adjust the relation between the downthrust and wing to get a good 
> > vertical upline and trim out the pull in the downline like Chad. Tell 
> > us how we can get a combination of vertical up with power, level with 
> > power (less power?) and vertical down without power that are all good 
> > without throttle to elevator trim. 
> > 
> > Jim O 
> > 
> > 
> > On Mar 10, 2008, at 5:31 PM, 
> > wrote: 
> > 
> > > Chad having a small tuck to the belly on left rudder only,, 
> > > is always a result in a little too much tail weight ,,providing 
> > > the stab halves and elevator halves are correct. 
> > > thats whats happening in your wandering 4/5`s 
> > > the tail weight as is ,,is making you add a little down elevator 
> > > trim because the wing is flying a little more positive. 
> > > You want to create the pos angle of attack with the wing only use 
> > > the tail weight only to adjust the feel for rolls and inverted flight. 
> > > engine thrust is contributory But ,not doing anything in the left 
> > > knife edge. 
> > > it would be happening in the right rudder too. 
> > > sorry Nat.. 
> > > approach it like this, before you reset the down thrust ,,,because 
> > > we want to know what really fixed it 
> > > increase the wing inc 1/32 " more positive or till it stopps 
> > > pulling in the downline , some airplane require the wing more than 
> > > 1/2 deg depending on weight and airfoils 1/2 pos. is not a hard 
> > > deck and you will have to move the cg forward to remove the left 
> > > rudder knife mix ,,move it till you find a sweet spot , between 
> > > downlines and both knife edges. 
> > > , Always remember tail heavy makes the elevator and rudder 
> > > sensitive and nose wweightmakes them a little numb but much more 
> > > effective 
> > > your spins,snaps entry and exits ,, up and downline,45`s will be 
> > > corrected 
> > > you will also see improvement in the wind due to the forward c/g and 
> > > pos inc. add pos wing inc till it stops pulling to the canopy in the 
> > > downs 
> > > and let us know what happens 
> > > Bryan 
> > > darn now I have given away the family secrets ,And 
> > > I have just made it harder to beat Chad 
> > > 
> > > ---- Nat Penton wrote: 
> > >> Chad 
> > >> Your problem is caused by the large difference between T/L and 
> > >> wing. Reduce 
> > >> the downthrust by 1 deg and reduce the wing incidence by 1 deg , 
> > >> and test. 
> > >> 
> > >> We will go from there. 
> > >> 
> > >> Your excess downthrust requires up elev trim when under power. You 
> > >> need to 
> > >> adjust wing and T/L to avoid other problems. If you just lower the 
> > >> wing inc 
> > >> it will go to the belly in knife. If you just reduce the D/T it 
> > >> will go to 
> > >> the canopy in 
> > >> knife. Nat 
> > >> 
> > >> ----- Original Message ----- 
> > >> From: "Chad Northeast" 
> > >> To: "NSRCA Mailing List" 
> > >> Sent: Monday, March 10, 2008 4:57 PM 
> > >> Subject: Re: [NSRCA-discussion] the joy of trim 
> > >> 
> > >> 
> > >>> Ok you trim masters, here is a tricky one for you. 
> > >>> 
> > >>> Bryan and I have been through this a bit last year but I ran out 
> > >>> of time 
> > >>> before the Worlds to fix it and just flew with what I had. 
> > >>> 
> > >>> On my Twister I have this pesky problem, the setup is like so, 
> > >>> 
> > >>> wing = 1/2+ Bryans suggestion and I like it 
> > >>> stab = 0 
> > >>> motor = factory claims 2.5 down, have not measured but could if 
> > >>> asked, I 
> > >>> have added more to cure a problem see below 
> > >>> CG = has been anywhere from 275 to 300mm from TE mostly with the 
> > >>> same 
> > >>> result. Currently its around 285-290 and it feels good at that 
> > >>> point. 45 
> > >>> ups inverted track almost hands off if under enough power. 
> > >>> 
> > >>> Symptoms, 
> > >>> 
> > >>> Plane flies well, at this setup I need 0 mix right rudder to ele 
> > >>> in knife, 
> > >>> and about 2% up ele with left rudder in knife, 
> > >>> about 1/32" down elevator with idle to fix a downline 
> > >>> Added downthrust as the increase in wing inc. and more forward CG 
> > >>> really 
> > >>> helped the mix in knife and made rollers easier, but forced an 
> > >>> increase in 
> > >>> downthrust as the plane started pulling to the canopy on uplines. 
> > >>> Downline mix remained the same. 
> > >>> 
> > >>> The big problem I cannot resolve is this, a 45 deg down upright 
> > >>> (motor at 
> > >>> idle) the plane pitches to the belly and will not track on its own 
> > >>> for any 
> > >>> length of time. If I switch the idle-down mix off its rock solid 
> > >>> on that 
> > >>> line. 
> > >>> 
> > >>> I am open to all suggestions now that I have a bit of time to play 
> > >>> with 
> > >>> this, I hope Bryan chimes in some more as I would like to continue 
> > >>> where 
> > >>> we left off last fall. If you suggest something I will do my best 
> > >>> to give 
> > >>> it a go and let you know how it works (provided it doesn't snow!) 
> > >>> 
> > >>> The plane is basically super locked in with this setup, except for 
> > >>> the 
> > >>> silly 45 down upright, which is a problem in cubans and such. 
> > >>> 
> > >>> Comments and thoughts from the masters are most appreciated :) I 
> > >>> consider 
> > >>> myself one of the, cant really trim that well but can fly through 
> > >>> it just 
> > >>> fine types :) 
> > >>> 
> > >>> Chad 
> > >>> 
> > >>> _______________________________________________ 
> > >>> NSRCA-discussion mailing list 
> > >>> NSRCA-discussion at lists.nsrca.org 
> > >>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion 
> > >>> 
> > >> 
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