2 line bellcrank developer

[fred cesquim]

not sure if this was discussed before here, but here´s my doubt: who and when developed the 2 line bellcrank that we use and what plane was the first to have it?

[Dan McEntee]

not sure if this was discussed before here, but here´s my doubt: who and when developed the 2 line bellcrank that we use and what plane was the first to have it?

   Research the Jim Walker patent, which I think he was awarded in the late 1930's or early 1940's, and then the court battle with Cox afterwards when Walker sued Cox over three alleged infringements. It is also covered in the book, "Do You Speak Model Airplane?" by Dave Thornburg. The whole story is almost "Movie of the Week" type drama! Going from memory, aa gentleman named Oba St. Clair from up in the nrothwest part of the US, developed a bell crank control system for flying model airplanes and it was quite a complex rig. He showed the system to Walker, hoping to land a job with American Junior Aircraft in addition to selling them his idea, but Walker blew him off, telling him is wasn't practical. A year or two later Walker filed for his patents, and out came the Fireball , the U-Reely handle, and the term "U-Control." Cox was sued in the early 1950s by Walker claiming that Cox infringed on all three patents. Cox presented Oba St. Clair and another gentleman from England, who had come up with the same idea completely independently, and successfully argued that all three were common knowledge and existed before Walker applied for his patents. There was also a good article in either Model Builder or Model Aviation on St. Clair back in the 80's or early 90s when he was still living. Some examples of St. Clair's work and models are supposed to be in the AMA museum at Muncie, Indiana. I think there were several others experimenting with the concept in the 1930s also.

  Type at you later,
   Dan McEntee

[fred cesquim]

   Research the Jim Walker patent, which I think he was awarded in the late 1930's or early 1940's, and then the court battle with Cox afterwards when Walker sued Cox over three alleged infringements. It is also covered in the book, "Do You Speak Model Airplane?" by Dave Thornburg. The whole story is almost "Movie of the Week" type drama! Going from memory, aa gentleman named Oba St. Clair from up in the nrothwest part of the US, developed a bell crank control system for flying model airplanes and it was quite a complex rig. He showed the system to Walker, hoping to land a job with American Junior Aircraft in addition to selling them his idea, but Walker blew him off, telling him is wasn't practical. A year or two later Walker filed for his patents, and out came the Fireball , the U-Reely handle, and the term "U-Control." Cox was sued in the early 1950s by Walker claiming that Cox infringed on all three patents. Cox presented Oba St. Clair and another gentleman from England, who had come up with the same idea completely independently, and successfully argued that all three were common knowledge and existed before Walker applied for his patents. There was also a good article in either Model Builder or Model Aviation on St. Clair back in the 80's or early 90s when he was still living. Some examples of St. Clair's work and models are supposed to be in the AMA museum at Muncie, Indiana. I think there were several others experimenting with the concept in the 1930s also.

  Type at you later,
   Dan McEntee

Great information Dan, looks like ti happened simultaneously by natural development of the mono line and the idea of the use of second line, thanks for the info!

[Dan McEntee]

Great information Dan, looks like ti happened simultaneously by natural development of the mono line and the idea of the use of second line, thanks for the info!

  There is a lot more to the story once you dig into it. One interesting side effect of the patent was that Walker was pretty ruthless with going after people, so during that time period that the patents were in effect, you saw many plans that were published or kits that were produced that had no illustration for the control system, and had the instructions  to "Use you favorite method of control" to get around it. Top Flite Models had a trainer called the "Whizzer" that just had flaps on the wings, and an oddball looking tiller system, just different enough to by pass the Walker patent. The Whizzer was designed by Carl Goldberg I believe, when he worked for Top Flite. I had a 1/2A model once when I was a kid made by Comet called "Lil Schmoe" and it had a bell crank out at the wing tip that was more of a tiller, and a wire pushrod that ran through some tubing that curved and turned towards the elevator . The wire attached to the tiller near the rear lead out. Again, just different enough to get around the patent. It worked, and I could fly the model OK. I would LOVE to find another kit of that model!!And the Whizzer just because of what they are.  Goldberg worked for Comet also , so he may have had something to do with the Schmoe also. I'll have to get my copy of "Speak" out again and re-read it. it may have had the English gentleman's name in it. St. Clair gladly testified for Cox, as he was beyond pissed at Walker over stealing his idea. Walker was so distraught after the court battle, that his health spiraled downward and he passed away a year or so afterwards, I think it was. Hi brother took over the company, sold it to Pacrta a few years later, and then Pactra dropped the whole line a few years after that, because they changed the AJ designs around so much that they didn't fly anywhere near as well as before. I love the history of the hobby!! You might want to check into Charles Mackey's book about Control Line Pioneers, or something like that. I either haven't read mine or I don't remember anything about it, but Mackey was around and very active in those early days and would have something to say on the subject.
   It's nap time right now, and after that I'll pull that book  out and flip through it !!
  Type at you later,
  Dan McEntee

[Steve_Pollock]

I've collected some of the variations on 2-line control systems.  All have been used in model airplanes.  Enjoy.

[Chuck Matheny]

I've collected some of the variations on 2-line control systems.  All have been used in model airplanes.  Enjoy.

I would give the "PULL / PULL" system [your last example] a try with a .049 powered model.
Form  a pair of large radius 90's in aluminum tubes and send Spiderline straight from the elevator horns to the handle.

[Dan McEntee]

   I got out my copy of Charles Mackey's book, " Pioneers of Control Line Flying", and there are several chapters that are dealing with this subject. Chapter 1 is " Who Was First."  Chapter 2 is " Oba St. Clair."  Chapter 3 is "Oba St. Clair/Jum Walker/Roy Cox. Oba's Meeting with Jim, Jim's Law Suit Against Roy. The Trial, Observations About Jim and Roy."  Other chapters through Chapter 9 have information and details. The weather has finally cooperated today, so I'm going flying but when I get back, I'm gonna dive into this book. I guess I had not read it before, as I didn't know Mackey got this far into it. It will be interesting!!
    Type at you late, film at 11!
   Dan McEntee

[fred cesquim]

I've collected some of the variations on 2-line control systems.  All have been used in model airplanes.  Enjoy.

interesting concepts! last one would have a lot of drag to stunt properly

[Steve_Pollock]

Fred, you're right -- and line spacing at the handle would be a problem.

[Brett Buck]

Fred, you're right -- and line spacing at the handle would be a problem.

   All the alternate systems have more-or-less the same problem - they suck!  There's a reason the bellcrank system is the only one that survived.

     Brett

[Dave_Trible]

..

[Dave_Trible]

This is Oba St. Clair’s airplane- it’s huge.

[Dave_Trible]

..

[Dave_Trible]

This is AMA Museum curator Mr. Smith showing me Oba ‘s flying ‘handle’ and how it works.

Dave

[Dan McEntee]

This is Oba St. Clair’s airplane- it’s huge.

   St. Clair's model and system can be compared to a marionette puppet, I think. It had more than one function, like a marionette's puppeteer can control several functions on his puppet. Again, going from memory, it had to do with where he lived at the time, and space limitations. I think it had aileron control at least in addition to elevator control. Gotta get into the book now as my curiosity is really high!!
  Type at you later,
   Dan McEntee

[Ken Culbertson]

The only one of those that has any chance of being even close to a standard bellcrank is the gear crank.  For all of the effort that it would take to make one all you would gain is linear control movement at the crank coupled to a non-linear flap horn, or was that to be rack and pinion too, and the elevator?  2lbs and counting.  Why.

Ken