Twister Mods

Gentlemen:

I've read several old posts related to lengthening the fuse for this plane approx 1-1/2 inches. lately I have heard about an article regarding the "Fancherized" Twister. Can someone share the essence of the article?? What other mods should I be planning on?

I have an Enya .35 scheduled for this project--but also could try the OS Max H .40 but I think that would be too much.

Thanks

Ted Fancher featured a Twister in several of the monthly columns he wrote when he was the Stunt Columnist for Model Aviationm; the term "Fancherized" came to be used to summarize the modifications. Personally, I think that the fuselage dimensions are reasonably good as designed, and if just one change were made that would most drastically improve the plane, it's a thicker (and bigger) stab, about 3/8" to 1/2" thick, with the elevator the next size thinner (1/4" for a stab 3/8").

Just in the past year, the subject has been gone into quite throughly at a couple of the C-L forums on the net; I suspect at least one of those is at that RCO joint, where no such thing as an archive exists, so the thread has been discarded.

No matter whether the choice for a power plant is a modern .25 or an old vibrator of a 35 (it's too small for a modern 35/40), almost all profile-fuselaged models benefit from greater rigidity in the nose, however obtained. Triplers have been popular, but carbon fiber mat sandwiching is also good. I've been extremely well impressed with the fuel feed improvements imparted by using a "well" sunk into the outboard side for the tank to nestle down between the motor mount beams.

Although the plane will fly fine "as is", a few mods can make it fly better. I agree with Kiwi in making the stab thicker and wider and longer (stronger, less flexing, more area). I would, also, increase the tail moment if I am going to increase the area. Butt joint a 2 inch piece of balsa to the back of the fuselage and move the stab back accordingly. The stab will hold things together and you don't need any other reinforcement. Bring the motor mounts all the way back to the wing, and use 1/16 inch Birch doublerson each side at least back as far as the middle of the wing, and I would bring them back as far as a couple of inches behind the wing, bringing it to a point, or rounding it so that you don't leave a shear point for the fuselage to break at this spot. A total tail area of 22 to 23% of the wing area would be good, although this is always a point of difference. I would not recess the tank. It weakens the nose and does not allow for adjustment up and down. You need to add an adjustable tank mount, adjustable leadout guide and adjustable tip weight. There are a number of variations of these and it becomes your choice.

As to power, we built one using our modified 35 and 40 FP for power turning a 12 x 6 BY&O prop. No problem, and it flew thrugh the wind. Just remember, power does not mean you are flying faster. You use pitch to determine lap speed, diameter for thrust. It is like the large tires used on a dragster. You need traction to pull through the wind. Of cocurse, you can get too big a prop and reach a point where the prop stops and the wing turns (a little extreme). But we have never found a 12 inch prop on a 48 inch wing to be excessive--especially when you are running it slow. As such, I would opt for the 40H over the Enya. The weight will be the same, but you will have more power (and probably turn an 11 inch prop with this one.)

If you have heavy wood or warped wood, replace it while you are building the plane. Heavy planes are called "Bowser".

I have built the Fancherized Twister and called it the "Twister II." I copied the articles from August through October 1987 Model Aviation by Ted Fancher and modified the SIG Twister Plans accordingly. The resulting Profile Stunter is excellent and has performed well in competition. It got John Sunderland a First in Expert Profile at the BRODAK 2000.

>Gentlemen:
>
>I've read several old posts related
>to lengthening the fuse for
>this plane approx 1-1/2 inches.
> lately I have heard
>about an article regarding the
>"Fancherized" Twister. Can someone
>share the essence of the
>article?? What other mods
>should I be planning on?
>
>
>I have an Enya .35 scheduled
>for this project--but also could
>try the OS Max H
>.40 but I think that
>would be too much.

The gist of the article was to lengthen the tail about 2" and to enlarge the tail area. I don't have a copy of the articles right now.

The Enya or the OS will fly it well enough. But they fly best with a stock 25FP swinging a 10-4 prop at ~11000 rpm. Bob Hazle has built 3 of them so far and they are far superior to most full stunt planes I've flown.

> The gist
>of the article was to lengthen the tail about 2"
>and to enlarge the tail area. I don't have a
>copy of the articles right now.

I've sent off to Muncie for copies of the articles, but for the sake of curiosity does anyone have the numbers, e.g. square inches of the stab, elevator, and thickness of each.

Once the articles get here, if anyone wants a copy I would be happy to oblige. It will probably take a few weeks...

The modifications made to the Twister Kit were as follows:

1. Lengthen fuselage by 3 inches aft of the flap line.
2. Add 1/2 inch balsa doubler on inside of nose to dampen vibration.
3. Add racer back ala Reno to fuser aft of present canopy and replace plastic canopy with 1/2 inch balsa.
4. Adjustable leadouts.
5. Tip Weight box.
6. 1/2 inch sheet balsa wing tips.
7. Half false ribs inbetween present ribs.
8. longer tail wheel wire ala Gieseke Nobler.

These are what I did to the kit and they worked well. I also added a modified GMA 4 oz fuel tank changed to uniflow with muffler pressure, carbon fiber tape on the main wing spars, and fiberglass pushrods.

These are what I did to
>the kit and they worked
>well. I also added
>a modified GMA 4 oz
>fuel tank changed to uniflow
>with muffler pressure, carbon fiber
>tape on the main wing
>spars, and fiberglass pushrods.
>

Tom, what engine/prop are you using?

Dear Brett,

You may not believe this, John Sunderland didn't either when I offered to let him fly it in Expert at the Brodak 2000, but the ship has a McCoy Thunderbolt Redhead 35 with an OS 40 NVA and a 10/6 EW RevUp prop. It is great to fly. John placed 1st in Expert Profile with it.

Tom McClain, Arlington VA

>Dear Brett,
>
>You may not believe this, John
>Sunderland didn't either when I
>offered to let him fly
>it in Expert at the
>Brodak 2000, but the ship
>has a McCoy Thunderbolt Redhead
>35 with an OS 40
>NVA and a 10/6 EW
>RevUp prop. It is
>great to fly. John
>placed 1st in Expert Profile
>with it.

I beleive it, but it might be just a little tough for everyone else to emulate!!

>The modifications made to the Twister
>Kit were as follows:
>
>1. Lengthen fuselage by 3 inches
>aft of the flap line.
>
>2. Add 1/2 inch balsa doubler
>on inside of nose to
>dampen vibration.

LTC Tom;

Was the kit stab/elevator used, or was it enlarged as mentioned by others? If enlarged, do you know what the size of each was?

As I recall, the Ted Fancher MA articles don't change the stab-elevator. Simply lengthening the fuse gives the tail more authority for the same size (torque=lever arm * force, and force is more or less proportional to area and amount of deflection).

I can't speak to any questions on whether a larger stab/elevator gives improved stability. For that discussion I'll refer you to the Rabe/Fancher Fireside Chat over on RCOnline.

Alan- whose Fancherized Twister is almost coming out of its perpetual construction phase.

Ted did not change the horizontal stab. He reduced the height of the vertical fin and rudder while adding 3 inches in length to the tail. The additional length gives more stab authority for a more stable ship. The Fastback canopy and ventral fin give the ship a great Reno racer appearrance.

I don't have the articles in front of me, but I was thinking that he did. At least we did in building ours, and that was after reading Ted's articles. The original stab is rather thin and a bit small by today's standards. We went to a thicker, larger (area) stab and corresponding larger elevator. Of course, like anything, this is always choice related. Will the original plane fly well? Sure. Is the modified version an improvement? Sure. Will you fly better with it? Not sure.

Leonard, I have the articles at hand and Ted used the original horizontal stab. By lengthening the fuse by 3 inches he reasoned he would have more stab authority. My experience with my Twister II shows he was right.

>stab-elevator. Simply lengthening the fuse
>gives the tail more authority
>for the same size (torque=lever
>arm * force, and force
>is more or less proportional
>to area and amount of
>deflection).

My thanks for the info.

>I can't speak to any questions
>on whether a larger stab/elevator
>gives improved stability. For that
>discussion I'll refer you to
>the Rabe/Fancher Fireside Chat over
>on RCOnline.

I wouldn't venture into that one even if I was wearing kevlar.