[NSRCA-discussion] the joy of trimming , left rudder tuck downline pulls
Chad Northeast
chad at f3acanada.org
Mon Mar 10 18:22:41 AKDT 2008
Ok boys, I will print off (because I would probably forget otherwise)
and take both Nat's and Bryan's suggestions with me to the field and
have at 'er :) Since they are different ideas to fix the same problem
it will be interesting to see which one (or maybe both?) work!
I know for a fact that more incidence and nose weight remove the left
rudder KE mix.
I am gong to be in Owego, NY from Wed to next Tues though so it will
have to wait until I am back. My wife will kill me if I go flying
tomorrow LOL :)
Chad
shinden1 at cox.net wrote:
> Right on target Matt !
> Bryan
> ---- Matthew Frederick <mjfrederick at cox.net> wrote:
>
>> I must be getting the hang of this... first thing I thought was add a little
>> incidence in the wing. Even though the down thrust is a bit much... Like
>> Bryan says all the time: wing incidence trumps it all. CG, thrust, and stab
>> incidence are used for extreme fine tuning. You gotta get that incidence
>> right first...
>>
>> Matt
>> ----- Original Message -----
>> From: <shinden1 at cox.net>
>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>> Sent: Monday, March 10, 2008 7:31 PM
>> Subject: [NSRCA-discussion] the joy of trimming ,left rudder tuck downline
>> pulls
>>
>>
>>
>>> 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 <G>
>>>
>>> ---- Nat Penton <natpenton at centurytel.net> 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" <chadnortheast at shaw.ca>
>>>> To: "NSRCA Mailing List" <nsrca-discussion at lists.f3a.us>
>>>> 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
>>>>>
>>>>>
>>>> _______________________________________________
>>>> 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
>
>
More information about the NSRCA-discussion
mailing list