Author Topic: Rudder offset on Twister? (Read 1861 times)

Dennis Heckel · « **on:** March 23, 2009, 10:20:30 PM »

Hello everybody,

What should I set the rudder offset on my Twister?

The plans say 1/4", is this too much?

Thanks for your help.

Dennis Heckel

Mark Scarborough · « **Reply #1 on:** March 23, 2009, 10:25:30 PM »

On the three I built, ( and all ships since) I use no offset on the rudder at all. If you have doubts, make an adjustable rudder with a rod and clevis so you can play with it.
that being said,, I would just build it straight.

Glenn (Gravitywell) Reach · « **Reply #2 on:** March 23, 2009, 11:07:32 PM »

I must agree with Mark. I stopped putting in offset a few years ago and have noticed no difference in the flying habits of the aircraft.

Brett Buck · « **Reply #3 on:** March 23, 2009, 11:25:17 PM »

Quote from: Gravitywell on March 23, 2009, 11:07:32 PM

I must agree with Mark. I stopped putting in offset a few years ago and have noticed no difference in the flying habits of the aircraft.

You should see some changes - like more overhead tension, and much smoother cornering (particularly on insides).

Rudder offset is a critical adjustment, so I would recommend setting it up to be adjustable, with very very fine adjustments (like 1/32 minimum change or less) and start with it dead straight ahead.

Brett

roger · « **Reply #4 on:** March 24, 2009, 02:50:11 PM »

i would never start with it straight, too scary@*0$o i allways start with some. the guys who say it dosent make a differanceare wrong, on anew plane gezzzzzzzzzzzz any thing could happen at least youll have some pull out there start with some and go back from there
roger

better safe then sorry

Randy Powell · « **Reply #5 on:** March 24, 2009, 03:04:08 PM »

It should also be noted that you should keep slop out of the system. I noticed on a recent plane that had an adjustable rudder that it was doing some goofy stuff. Then noticed that it had developed quite a bit of slop in the rudder adjustment system. Fixed that and goofy stuff went away.

Dennis Moritz · « **Reply #6 on:** March 24, 2009, 06:17:52 PM »

How does rudder offset effect the airplane in a different way from engine offset and leadout offset? I have assumed that adjustable leadouts can tune in yaw.

Brett Buck · « **Reply #7 on:** March 24, 2009, 10:28:38 PM »

Quote from: Dennis Moritz on March 24, 2009, 06:17:52 PM

How does rudder offset effect the airplane in a different way from engine offset and leadout offset? I have assumed that adjustable leadouts can tune in yaw.

Because the effects of rudder offset are variable depending on the speed, the effect of engine offset is a function of thrust, and the effects of leadouts is a function of the line tension. None of those things stay in balance as you maneuver. If you, say, add a bunch of rudder offset and then move the leadouts forward to get it straight in level flight, as soon as you change the tension to maneuver, the balance changes, and you get roll and yaw oscillations (typically, you will nose in on every hard corner with this set of things).

Lots of people trimmed this way for a lot of years, so it will certainly result in adequate line tension, but it's not optimal - at all. I am sure there will be a hundred people claiming they thought of it in 87 B.C. but Ted and I figured it out somewhere in the mid-90's.

Brett

Dennis Heckel · « **Reply #8 on:** March 25, 2009, 04:05:25 PM »

Life sure was easier without these forums. I didn't know I had problems until I read about it here. I always set the rudder, added the amount of wing tip weight and set the leadouts where the plans said, sometimes put 2 washers under the front engine mounting bolts, set the engine at full speed and launched. I sure had a lot of fun. The plane flew and life was good. Now I over think every move I make when building. Oh well, I still don't fly very well but I am working on it. And I'm still having fun!!!

Go figure.

Thanks for all your help.

Dennis Heckel

roger · « **Reply #9 on:** March 25, 2009, 06:07:44 PM »

now you got it...

Brett Buck · « **Reply #10 on:** March 25, 2009, 11:24:03 PM »

Quote from: Dennis Heckel on March 25, 2009, 04:05:25 PM

Life sure was easier without these forums. I didn't know I had problems until I read about it here. I always set the rudder, added the amount of wing tip weight and set the leadouts where the plans said, sometimes put 2 washers under the front engine mounting bolts, set the engine at full speed and launched. I sure had a lot of fun. The plane flew and life was good. Now I over think every move I make when building. Oh well, I still don't fly very well but I am working on it. And I'm still having fun!!!

Gotta remember that we have a huge range of guys reading these forums, all the way from rank beginner to multiple national champions and everything in between. What seems pointless to some will be a critical issue to others, and what is obvious to some is completely new and a breakthrough for others. So you get all levels of responses.

Brett

RC Storick · « **Reply #11 on:** March 26, 2009, 09:42:41 AM »

Try to remember the info you get here is worth exactly what you pay for it.

roger · « **Reply #12 on:** March 26, 2009, 04:15:10 PM »

also back in the late 40s and 50s we still had the nats and such ,and still had a lot of fun, but today everything has to get so sophisticated it takes all the fun out of it. we still landed planes on carriers and flew a wing with a small tale and a ribbon on it and had fun. heck you can fly a stop sign with a motor on it and even a lawn mower on 2 lines . why must everything be so sophisticated.ive been on this web site for about a year now, and i see some things that are really helpful but other things that are nuts, this is not rocket science guys ts swingin a plane around a circle on 2 wires oh yes some of us can get a little creative and do a loop or two to get that that that crazy

Mark Scarborough · « **Reply #13 on:** March 26, 2009, 04:49:42 PM »

Roger,
it totally depends on what you want out of the hobby, if you want to swing a rock on a swing then none of this stuff is that iimportant, but if you want to compete, well thats a different kettle of fish

Randy Ryan · « **Reply #14 on:** March 26, 2009, 05:15:13 PM »

Quote from: roger on March 26, 2009, 04:15:10 PM

also back in the late 40s and 50s we still had the nats and such ,and still had a lot of fun, but today everything has to get so sophisticated it takes all the fun out of it. we still landed planes on carriers and flew a wing with a small tale and a ribbon on it and had fun. heck you can fly a stop sign with a motor on it and even a lawn mower on 2 lines . why must everything be so sophisticated.ive been on this web site for about a year now, and i see some things that are really helpful but other things that are nuts, this is not rocket science guys ts swingin a plane around a circle on 2 wires oh yes some of us can get a little creative and do a loop or two to get that that that crazy

Roger, your real name wouldn't be Floyd would it???

roger · « **Reply #15 on:** March 26, 2009, 08:06:46 PM »

NOPE!!!

ray copeland · « **Reply #16 on:** March 26, 2009, 08:13:33 PM »

Goin back to the Twister build, from all this info i plan on an adjustable rudder on mine just for kicks, also last night as i finished framing the wing i noticed some forward sweep! Not good i think , where did this come from as i pinned to the plans? Got out a straightedge tonite and the line on the trailing edge of the plans is this way but not the leading edge!! I will continue the build like it is but i am disappointed unless this is the way its supposed to be. Has anyone else noticed this on the twister plans? Sorry for hijacking this thread.. Thanks, Ray

john e. holliday · « **Reply #17 on:** April 03, 2009, 06:55:48 PM »

Years ago when I was getting started in this mad hobby, a gent by the name of Bob Palmer wrote an article about flying stunt. He wrote about the experiments he ahd done on various planes. Like flying a Chief with a .19 size engine.

He made a statement in the article about rudder offset. He had a plane that was flying good. During the day he knocked the rudder off. He stated he was amazed at how well the plane started to perform. But, then the engine quit and he stated that is when he noticed the difference of the rudder not being there.

As some have stated already, make the rudder adjustable. Also don't forget all the other stuff like, adjustable leadouts and weight box on outboard wing. Don't forget the fuel tank. It all depends if you want to get a plane that will fly and do what it's supposed to do or just fly a rock on a string.

Have fun, that is the important thing. DOC Holliday

Author Topic: Rudder offset on Twister? (Read 1861 times)

Dennis Heckel

Rudder offset on Twister?

Mark Scarborough

Re: Rudder offset on Twister?

Glenn (Gravitywell) Reach

Re: Rudder offset on Twister?

Brett Buck

Re: Rudder offset on Twister?

roger

Re: Rudder offset on Twister?

Randy Powell

Re: Rudder offset on Twister?

Dennis Moritz

Re: Rudder offset on Twister?

Brett Buck

Re: Rudder offset on Twister?

Dennis Heckel

Re: Rudder offset on Twister?

roger

Re: Rudder offset on Twister?

Brett Buck

Re: Rudder offset on Twister?

RC Storick

Re: Rudder offset on Twister?

roger

Re: Rudder offset on Twister?

Mark Scarborough

Re: Rudder offset on Twister?

Randy Ryan

Re: Rudder offset on Twister?

roger

Re: Rudder offset on Twister?

ray copeland

Re: Rudder offset on Twister?

john e. holliday

Re: Rudder offset on Twister?