Ringmaster waggle

[John Castle]

I don't know what else to call it.  This is an Estes Ringmaster jr. with a TT .15, 8x4 prop and 42' lines. There is plenty of rudder offset and the engine is offset by one small washer under the front mounting holes. The plane grooves very well and has good pull in level and inverted flight. The problem is whenever I do a loop, when the loop is complete the plane will do a waggle in the yaw axis. It will yaw back and forth two or three times before it catches itself and flies on. Any ideas on what is causing this?

[Mark Scarborough]

John, First step, is it all aligned accurately,,Its possible that the rudder offset could be causing this or the leadouts arent quite in the right place.
more experienced trim experts than me will hopefully weigh in

[Dick Pacini]

Too much rudder and engine offset can cause that problem.  The plane is always fighting against the desired path.

[Richard Grogan]

John,how much elevator throw do you have, and how big of a loop are you talking about that this trouble follows? Sounds like too much elevator,tight loop and it is recovering from a near stall condition.More info please...

[John Castle]

John,how much elevator throw do you have, and how big of a loop are you talking about that this trouble follows? Sounds like too much elevator,tight loop and it is recovering from a near stall condition.More info please...

There is plenty of elevator throw and I did find that it is fairly easy to stall it going into a tight loop but in this case I was trying to do larger 45 degree contest type loops. I do agree that the plane acts a little like it is stalling. I just can't figure out why it would do it after the loop is done.

[FLOYD CARTER]

You seem to have enough power.  Big problem with most Ringmasters;  they are too heavy for that thin wing section.

Floyd

[wayne scruggs]

Well, John could it be that you are hitting your propwash when you complete the loop?

[John Castle]

Too much rudder and engine offset can cause that problem.  The plane is always fighting against the desired path.

I guess I will start by removing the engine offset as that is the easiest change to make.

[john e. holliday]

Hang it by the leadouts first before doing anything.  If it hangs nose down quite a bit by holding the front lead out that is an indication of too far back or is just plain nose heavy.  I hope you did balance it.  Also does it dive for the ground when the engine quits?  Another sign of nose heavy.  Hope it is light also as someone has stated already the airfoil is thin and not too much wing area.  My thoughts.

[John Castle]

Hang it by the leadouts first before doing anything.  If it hangs nose down quite a bit by holding the front lead out that is an indication of too far back or is just plain nose heavy.  I hope you did balance it.  Also does it dive for the ground when the engine quits?  Another sign of nose heavy.  Hope it is light also as someone has stated already the airfoil is thin and not too much wing area.  My thoughts.

Ah yes! Start with the obvious.. I didn't build this plane. It was a swap meet special and I assumed the builder adjusted the CG already. The quick balance it on your finger test seemed ok but after setting it on a proper CG machine it turns out to need a large chunk of lead on the tail to balance it properly. It will be interesting to see how it flies after the adjustment..

Thanks,
John

[Steve Helmick]

I bought an airplane from a local Advanced flier (the guy I flew with in High School!), after he flew it for a season and won a bunch of trophies with it. First time I flew it, I knew the CG was too far back. That was about 2 years ago. I moved the CG forward before I flew it again. I'm still tweeking the CG. Pretty soon, I may get this thing flying right....but it's not bad right now. Moral of the story is: Never assume, never stop adjusting, keep thinking of ways to make that old dog fly better! It needs a better fuel tank, #1. One of these days, I'm gonna try reducing the tipweight by a gram or two. Really.

What size lines are you using? You probably should use .012's. I'm thinking "line whip" could be your problem. Get rid of the rudder and engine offset. Adjust the LO's to get the maximun line tension overhead. Play with propellers! I think Thunder Tiger Cyclone's come in 8 x 4.5. Should work!

Is there any news on the rumored new circle(s) at EGAM? A nice new 8 lane freeway to get there would be nice, too!  Steve

[Greg L Bahrman]

Tooo much rudder

[Perry Rose]

Bigger engine. Fox or OS .25. I've had both on mine. Get the lap times in the 4.8 second range, 58 foot eye to eye. That wing has a need for speed.

[Russell Shaffer]

Is there any chance that it is just too heavy?

[Brett Buck]

Is there any chance that it is just too heavy?

   Greg had it  - lots of rudder offset is the classic cause for this, and exactly the reason we have cut airplanes up to get rid of it. Straighten out the rudder, put in a teeny bit of engine offset and move the leadouts where they belong, and right next to each other. CG at about 15%, leadouts about 3/4" to 1 1/8" behind the CG.

   I am also a little concerned about the "plenty of elevator movement" part. One of the keys to performance is to make sure the elevator moves very slowly - just a little bit for a lot of handle movement. See numerous previous posts on the topic of Ringmaster trimming - at this point it's pretty well sorted out.
 
     It almost certainly correctable, so don't be discouraged.

     Brett

[Larry Fernandez]

Bigger engine. Fox or OS .25. I've had both on mine. Get the lap times in the 4.8 second range, 58 foot eye to eye. That wing has a need for speed.

WRONG !!! I flew a full sized Ringmaster with an FP .15 and it worked just fine. In fact Uncle Jimby won OTS with it one year at the Golden State Meet. There is no need to put a .25 on a Junior.
I would remove all but the very slightest rudder offset, remove all engine offset. make sure it balances around 15-18% and keep the elevator travel at around 20 degrees. If the CG is in the right location, you will not need that big elevator to travel much. Check the lead-out location at about 3/4 inch behind the CG and go fly.

Again, I had one of the best flying Ringmasters around and I had a lot of help from my West Coast Stunt Heros.
This set-up will work very well for you.

Larry, Buttafucco Stunt Team

[Osni Renato]

When the Brazilian squadron was in Brodak Fly in 2008 all had ringmaster.
We noticed that everyone had the same problem: stalle to excessive movement of the elevator.
Especially in more closed maneuvers. The plane lost support is bent sideways loosing control lines.
Learn to better control commands and start to make less abrupt maneuvers with softer angles. Thus the angle of attack not let the plane stall.
I hope have helped.
Regards Osni

[Brett Buck]

Bigger engine. Fox or OS .25. I've had both on mine. Get the lap times in the 4.8 second range, 58 foot eye to eye. That wing has a need for speed.

  I think you are thinking of the full-sized Ringmaster, not the Jr. A Jr is grossly overpowered by even mild 19s and a well-built one would be just fine with a Medallion or Enya 09.  My first "big" airplane was a Ringmaster Jr. and it was absolutely a bomb with a ST g20/23. It went around 80 mph on .012x60. A Thunder Tiger 15 is *plenty* of power to get it going far faster than necessary. I agree that it's not going to chug around like a Nobler but power is almost certainly not the problem.

   Brett

[Jim Kraft]

I agree with Brett. My first "big" plane was a Jr. also. I had a slant plug Fox 15 on mine, and it flew pretty well. I still have the engine, and I am keeping it away from the "hurl guys". I may build another one. I always thought the 35 sized one flew better, at least at about 26 to 28 oz.

[Larry Fulwider]

. . .
    . . .   I am also a little concerned about the "plenty of elevator movement" part. One of the keys to performance is to make sure the elevator moves very slowly - just a little bit for a lot of handle movement.
 . . .

     Brett

Looking for something else entirely, I found this Brett quote on SSW:


 . . . Also, once you get that fixed, you will still want to avoid frustration in another way - by preventing the classic "Ringmaster stall". What you need to do to avoid this is to adjust the control response to be very, very slow with full handle movement. Either move the elevator pushrod further from the hingeline, or narrow the handle spacing, so that with full wrist movement, you only get about 15-20 degrees of elevator motion in each direction. Don't leave the ratios alone, and "block" the motion to limit it, slow the RATE of movement down.

Brett

  Which is a little more detailed version of the one posted here

       Larry Fulwider

[Brett Buck]

I still have the engine, and I am keeping it away from the "hurl guys".

    Just for the record, the engine *must be removed from the airplane* before an official hurl distance may be recorded. It's the law!

     Brett

Here is the natural habitat of the Fox 15 slant-plug:

[Jim Kraft]

And that is why I keep mine locked away in my special engine stash. I may get it out and mount it on a plane where it will be "unhurlable". Someday I will put it on ebay as the only unhurled Fox 15 in existance. It will be worth mucho monies. Life is good.

[George]

I prefer to hurl my Fox .15's around on an Akromaster but my Ringmaster Jr. has an Enya .09...

George

[Bill Gruby]

 I'm certainly no expert here but I know for sure if you have more than 20 degrees of elevator deflection in either direction you are asking for trouble. That elevator at excessive deflection is a "barn door" it will stall  for sure and cause the "Waggle" you are speaking of.

  "Billy G"