Twister flaps

[GonzoBonzo]

Hey all,

  I just started building a Sig Twister.  I noticed that one of the flaps is a 1/16 of an inch bigger in chord.  Should I:

A.  Sand them equal.

B.  Mount the bigger one on the inside, or outside for a slight advantage in performance.

I'm kind of confused on this subject.  I've read a lot of posts about larger inside panels to compensate for the slower speed of the inside wing, and line weight.  But I've also found posts about having a larger outside flap to compensate for the tip weight.  Can anyone shed some light on this subject?

TIA,


Gonzo

[Randy Cuberly]

Hey all,

  I just started building a Sig Twister.  I noticed that one of the flaps is a 1/16 of an inch bigger in chord.  Should I:

A.  Sand them equal.

B.  Mount the bigger one on the inside, or outside for a slight advantage in performance.

I'm kind of confused on this subject.  I've read a lot of posts about larger inside panels to compensate for the slower speed of the inside wing, and line weight.  But I've also found posts about having a larger outside flap to compensate for the tip weight.  Can anyone shed some light on this subject?

TIA,


Gonzo

On the Twister the inboard wing is a little longer than the outboard and therefore the inboard flap is a bit longer than the outboard.  Making the outboard flap slightly wider actually makes the area of the two equal or at least approximately equal.
I believe most experienced stunt fliers now aim to make the flaps of equal area on stunters.
A few like myself actually lean toward making the outboard flap slightly larger than the inboard (only about 3-5%).  The reason for this is the theory that since we fly in a circular path the airplane is slightly crabbed toward the outside of the airflow and the fuselage has a potential to blank a portion of the flap area close to the fuselage on the outboard side.  Just theory but it does seem to work.  It also allows for a bit more tip weight to be carried without dropping the wing on corners.  The extra tip weight helps on overhead maneuvers, especially in severe wind.
At least that's my story and I'm sticking to it.

I've noticed little tabs growing on the outboard flaps of some folks in the past, that don't support this theory.     These little tabs magically appear during trimming functions on the airplane.

Randy Cuberly

[Bill Little]

Like Randy said, I would use the wider flap on the outboard wing.  As long as it is the correct length.

BIG Bear
RNMM/AMM

[GonzoBonzo]

On the Twister the inboard wing is a little longer than the outboard and therefore the inboard flap is a bit longer than the outboard.

Randy, my plans show equal panels,  24 in. each.  The wing has zero sweep, and taper, so I guess I could offset it any amount I like.  The flaps are equal length, and are an extra 1/4 in. long for wingtips I guess.  So,  If I were to offset the wing more than a quarter of an inch, I'd have to make new flaps, which would be a bummer. 
They are surprisingly straight, and very stiff unlike the fuselage which probably gave the plane it's name.   

[Joseph Lijoi]

Randy, my plans show equal panels,  24 in. each.  The wing has zero sweep, and taper, so I guess I could offset it any amount I like.  The flaps are equal length, and are an extra 1/4 in. long for wingtips I guess.  So,  If I were to offset the wing more than a quarter of an inch, I'd have to make new flaps, which would be a bummer. 
They are surprisingly straight, and very stiff unlike the fuselage which probably gave the plane it's name.   

All due respect, Randy is incorrect, your plans are correct, the Twister has equal panel wings.  Build the wing to your plans and use no offset, you don't need it on a profile.  You will end up with about a quarter ounce of tip weight.  We had  guy here that built a beautiful profile with unequal panels and ended up putting tip weight in the INBOARD tip to prevent hinging in hard corners.  If one flap is wide in chord then Randy is correct, you want this on the outboard panel, the theory here is that you can carry more tip weight without hinging in hard corners.  Do not put the wide flap on the inboard.  I would build it to print or Fancherize it.  Hopefully the experts will chime in here.

[john e. holliday]

As Joseph says,  follow the plans.   Remember this is a profile and look at all that stuff hanging outside the fuselage center line.   The kit was designed by an expert and he should know how it works.   

[GonzoBonzo]

Thanks guys, outboard wing it will be.

Doc,  I never have "stuff" hanging out of the fuselage, unless I've had a couple of Margarita's.     It will be an electron burner.  I'm thinkin' po' man's Yatsenko.


http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXAGVE&P=7

You can get the fuse, and cowl for under $100.  Probably too big for the twister wing though?

[Jerry Higgins]

My son and I built two kit Twisters and one with a builtup fuselage a few years back.  We had equal wing  panels and equal size flaps on all three and there was no roll in flight on the profile or built up fuselage.  The one we built with the Fancherized modifications was the best performer.

Jerry

[GonzoBonzo]

The one we built with the Fancherized modifications was the best performer.

Jerry

Thanks Jerry.

I was contemplating moving the stab back a couple of inches.  The general consensus seems to think it helps.