Twister Question

I was going to power my Sig Twister with an O.S.25 FP-S. Question: Is this enough motor to power this model ?

Dave, I recently built two Twisters. One is powered by an Irving .25 the other by an ASP.25. Both fly well and I have plenty of power with either engine. The twisters are stock with the exception of a set of false ribs between standard ribs and I modified the rudder and the canopy. I use 5% Sig fuel and run either an APC 9x4 or 9x6, getting about 5 second laps on .015x60 wire.I use a 4oz. Sullivan clunk tank set up with muffler pressure and set the rpm at about 10.5M on the ground. Remember, the Twister was designed for a Fox .35 and does well with that engine, but the newer .25's give much more power in my opinion. But, I am not an expert, so my advise and $1 will buy you a cup of coffee in many resturants nationwide.
Joe Just

YES...Just make your plane light on have FUN

Thanks for all the good advice guys. Joe, I think I'll try the 0.S. 25 FP-S and see what happens. If underpowered, there's a new O.S.40 LA-S in the box on the shelf. I too am perplexed by Gary's expierience with the wings folding up and his Twister becoming a cruise missle. Sounds like it was spectacular but I hope nobody got hurt. For Len, Ted Fancher modified his Twister by adding 3 inches to the back of the fuselage. Do you recommend this modification for an airplane that's just going to be used for general sport flying ?

I had an OS Max 25LA on a Twister too and it flew great. I experemented with several other engines. The last engine that I tried was an OS Max 40LA with 11x6 prop. It flew about 5 laps with the OS 40 engine then both wings ripped completely off the fuselage. The airplane turned into a cruse missle and self distructed. LOL. Do not put a 40 size engine on your Twister.

>I had an OS Max 25LA on a Twister too and it flew great. I
>experemented with several other engines. The last engine
>that I tried was an OS Max 40LA with 11x6 prop. It flew
>about 5 laps with the OS 40 engine then both wings ripped
>completely off the fuselage. The airplane turned into a
>cruse missle and self distructed. LOL. Do not put a 40 size
>engine on your Twister.
>
>Gary Weaver [email protected]

I don't understand this one, Gary. The Twisters are not mushy wood or inferior construction. There are probably more Twisters flying with 40 FP engines than any other combination out there. Every contest around here seems to have two or three of them in Beginner/Intermediate powered that way. We powered one with a modified 40 FP and a 12 x 6 prop. Never had a problem. There was one norotrious plane on the contest trail a while back whose owner was cleaning house in expert with one--powered by a 40 FP. I would consider it a perfect combination. Weight is very little more than the 25 (especially with a tongue muffler) and power is addictive. Just put it on a little longer lines.

I pulled full up to do a wing over and both wings folded up and ripped off. Not much else to say. I think the very sharp turn was too much load on the wings. Both wings broke off at the fuselage.

>I pulled full up to do a wing over and both wings folded up
>and ripped off. Not much else to say. I think the very
>sharp turn was too much load on the wings. Both wings broke
>off at the fuselage.
>
>Gary Weaver [email protected]

It may have been an inadvertent building goof here, Gary. (No knock on your skills. Just a statement of probable cause.) I have a Tutor that I rescued frmo its destination in a trash can at a St. Louis contest. It had the same problem--wings folded at the fuselage. In his case he put the sheeting on wrong. The grain ran the direction of the fuselage. (All I saved from the wing was the ribs). Here I am going to assume you built it correctly. But it is possible for glue joints to let go (happens to all of us--if it hasn't, it will). Or maybe you sanded into the sheeting when you put the fillets on. There is a strong sheer force at the fuselage joint, and if we weaken it in any way, it can go.

Ted suggested in a thread long past that the wing be covered before inserting into the fuselage. That way the silkspan does not end at this point adding stiil another stress riser. Matt of late has been using light fiberglass cloth to reinforce the center section out beyond the fuselage joint, and rounding the ends to again alleviate the sheer joint. But the structure of the Twister should be amply strong as-is if the wood is not thinned by excess sanding and all glue joints are glued solidly. It should have held. But saying "should have" and what actually happened may be two different things. It would be interesting to know a little more about this, though.

Gary, I've had 3 Banshees and a modified Banshee all with os 40's pulling my arm off and have never torn a wing off. I've made some sizable craters, ground the canopy and fin level with the fuse, but the wings they be solid.

Course I've never been able to get a 9 second lap with perfect squares out of it either.

I built the Twister from the kit. I followed the instructions and the balsa on the center section of the wing had the wood grain going in the direction of the wing. I also used the 1/4" x 1/4" balsa spars that came with the kit. The wings were covered with silk span from the kit and painted with sig dope. I knew nothing at all about balance then so the airplane may have been nose heavy. Not sure I even had the correct wing tip weight either. This was the first airplane I ever had with wing flaps. It took me several weeks of experementing to get the wing flaps and elevator adjusted so the airplane would fly good. I finally learned that my control horn on the flaps was too short and after changing it from about 1/2" to 1.5" and made some adjustments it flew much better. I flew the airplane for a long time and had lots of fun with it and so did my son John. One day I changed the adjustment on the elevator so the airplane would turn sharper more like a combat airplane. When I pulled full up the airplane appeared to make a 90 deg turn in about 3 ft radius and both wings folded up and ripped off. The airplane was probably doing 70 mph.

Oh, THAT Twister.

never mind

70 mph, huh? What prop was on it?

>I had an OS Max 25LA on a Twister too and it flew great. I
>experemented with several other engines. The last engine
>that I tried was an OS Max 40LA with 11x6 prop. It flew
>about 5 laps with the OS 40 engine then both wings ripped
>completely off the fuselage. The airplane turned into a
>cruse missle and self distructed. LOL. Do not put a 40 size
>engine on your Twister.

I tend to agree with your advice, but not your reasoning. There is nothing intrinsically wrong with the design of the wing that would suggest extraordinary weaknesss. To the contrary, it's built like many models of the era and has proven satisfactory. I would look to a worksmanship issue rather than design.

I think a 25FP is generally superior for performance reasons, but a 40-size stunt engine is not going to rip the wings off a Twister that is properly constructed.

>I had an OS Max 25LA on a Twister too and it flew great. I
>experemented with several other engines. The last engine
>that I tried was an OS Max 40LA with 11x6 prop. It flew
>about 5 laps with the OS 40 engine then both wings ripped
>completely off the fuselage. The airplane turned into a
>cruse missle and self distructed. LOL. Do not put a 40 size
>engine on your Twister.
>
>Gary Weaver [email protected]

I remember a Tutor that Ronnie Farmer had in Atlanta with an OS35 that was bored out to about a .50 (used a ST60 piston&sleeve). He routinely flew the entire pattern with it, there was no problem because of the engine even though the plane only weighed 30-32oz. Properly built the twister which is larger should have no problem with a 40 on the nose.

>I was going to power my Sig Twister with an O.S.25 FP-S.
>Question: Is this enough motor to power this model ?

My Twister is powered with the FP 25 and an APC 9x4 prop. Sig 5% Champion fuel and .015x58' lines. I use a 4oz plastic clunk tank but typically only put in 3oz of fuel. It does far better than I do.

A member of our club does quite well in advanced using a Twister with a 40fp. One head gasket 10.5x4.5apc, powermaster 22%(50/50)5%. He's run this plane for the last two seasons with no problem using a number of different fp40s, including an iron piston steel liner engine. Engines were swapped out of curiosity. The original a hand me down with lotsa seasons doing various duty. Dan Banjock put this plane in either first or second (I think) at Brodaks flying the profile event. In any case it placed high. The reserve power much appreciated. Doesn't it get windy where you fly. Don't see why the 40 would have been the cause of folded wings, unless there was a structural issue. The combo of a head gasket, the recommended prop and fuel work for us in different planes including an Oriental, Accentor, Flitestreak and different foamie knock abouts. Actually got my Streak to fly too slow.

Sometimes Bob Zambelli gouges out the head and makes it a hemi. That mod tames the beast as well. Most of us simply put in a head gasket use the fuel etc. and laugh about the ease and simplicity of it all.

I flew one thru Intermediate and into Advanced. All film covering (three separate times, but that's another story). Began with an Enya 35 (not a good stunt run, but I was learning), a Fox 35 (with a worn out bushing that was a bitch to start and didn't really make much power - again, I was learning) a K&B 40, with 10.5 / 4.5 ASP (Tom Hampshire introduced me to the prop), and ended with a long use of my favorite engine, a Tower 40 and same APC prop set up (much lighter than the K&B). 60-64 ft lines, depemding on wind.

I think they're great (as long as you add wingtips and get rid of the butt ugly rudder). I added 2 inches to the fuse after someone backed over the tail section (never let your mother in law near your aeroplanes), and increased the overall size of the stab/elevator maybe 15%.

I don't question the .25, but the .40 Tower allowed me to take home a good bit of hardware.

As to the wings folding - can't explain that. Hit the ash tree out front - 17 patches to the film, but no structure damge. A collision with a huge warbird of a stunter in the next circle - one patch and a new prop, and a new set of lines. Another collision with an old Veco Chief in the other circle, and it got written off (both planes, this time). Remember them 64 ft lines I was talking about? Not at the field with the two tight circles designed around 60 footers. Well, not any more, that is.

The SLOW club of MD wrote about that maggot visitor from Virginia for months.

Clayton,

64 Foot lines work O.K. in your front yard if you remain on the cement block and don't wander. However, you must watch out for unusual people stepping on your airplanes - like, um, your own self. The plane was flying O.K. at the Nats, it just didn't like all the extra tip weight much, so I took some of the weight out of the box. I guess someday I will learn not to try and fly during 25-30 MPH gusts. Oh well. No one is interested in buying my Jett .61 so I guess I will just have to use it on my Excelsior. I just need a place to build the rest of the plane!!!!

My buddy's Twister is stock and it flies great with an old OS Max S 35 with muffler. Mine is modified..larger wing, longer body, heavier tail feathers and it flew great with a Tower 40.

A Twister thread can't come up without mention of the TwistMaster

My modified Twister has been flown with 4 diferent engines, OS 35S, OS 40FP, Saito 30 and now a Saito 40 four banger. The Saito 40 is by far the best of the bunch.

I am sure your Twister will fly fine with a 25 for sport flying. Most of us that are running 40's want something that will handle 20 MPH wind at a contest which takes more power. (Insert Tim the Toolman grunt here.)

I am rebuilding my Twister that I had a L&J Fox 35 on. It suffered from the dreaded "I think I can" syndrom in the overheads. I replaced the wing spars with bass wood for strength and the wing has survived three crashes. All three while inverted, clipping the rudder on the ground and pancaking the plane, never a hard impact into Mother Earth...

I am redoing the fuse making it 2 1/2" longer and putting a Thunder Tiger .42 GP (as soon as I get the venturi and NVA from Leonard) The plane originally came out a little heavy (I forget how much) and it was right on the edge of what a Fox would like to haul around. (saving the L&J for a Barnstormer) The .42 GP should be a nice choice.

Hi Dave,
Yes, it will power it under the conditions everyone else has stated: light enough airframe, not flown in high winds, etc..
For *contest* flying, you might want more, but if that's the engine you have, go for it!
Bill <><

>Hi Dave,
>Yes, it will power it under the conditions everyone else has
>stated: light enough airframe, not flown in high winds,
>etc..
>For *contest* flying, you might want more, but if that's the
>engine you have, go for it!

Most people around here fly them with 25FPs, essentially stock. There is no lack of power, as long as you don't "improve" the engine.They make superior contest machines due primarily to engine performance.

Start "fixing" the engine, trying to "get more power" to swing more lumber, then you will find it lacking.

I'm too simple minded to do anything less than keep it stock. Besides, it's a very reliable and predictable powerplant as it is. I was just inquiring about enough power for alot of wing area. Thanks for the advice....I'm going to try it. If I don't like it, I've got a .40 LA in the box.

> Most people around here fly them with 25FPs, essentially
>stock. There is no lack of power, as long as you don't
>"improve" the engine.They make superior contest machines due
>primarily to engine performance.
>
> Start "fixing" the engine, trying to "get more power" to
>swing more lumber, then you will find it lacking.
>
> Brett

Brett, Thanks for this answer. I have spent some time trying different .25's this past year and could not agree more. However I am not an expert.Your input in this (.25) regard is really what many need to hear!
Joe