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

Koenig, Tom Tom.Koenig at actewagl.com.au
Tue Mar 11 12:33:21 AKDT 2008


Well...even though I have learnt this from Bryan many years ago, I too
am GLUED to the computer, awaiting- I seem to have lost my path
recently. It was just easier to simply fly the pig, rather than do the
work!!!
 
There are probably only a handful of people on this PLANET who I'd
listen to for trimming or design advise, starting with Bryan and Nat!
 
I will never again 'trust' the big names for aeroplane design etc.
 
Tom
 
 
 
 

________________________________

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
vicenterc at comcast.net
Sent: Wednesday, 12 March 2008 6:42 AM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] the joy of trimming ,left rudder tuck
downline pulls


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 Me! ssage-- --- 
	> > 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 
	> > o! ff, 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 ta! il weig ht
,,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 w! ing
mor e 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 ma! de it h arder 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 su! ggest s omething 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.n! srca.or g 
	> > >>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

	> > >>> 
	> > >> 
	> > >> _______________________________________________ 
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