3-line control...Cox style!

Back in the day, I had one of these wonderful little Ryan ST-3's (photos from Ebay).  Powered by an exhaust band .020, it's tiny wheels couldn't handle the dirt in our ballfield, so, I'd fly it from the smooth pavement of the main street in my home town.

It was my first experience with a throttled model airplane, and I taxied it as much as I flew it.  It was a big thrill to pull the trigger and takeoff, then back it down for some slow cruising.  The big draw-back was the peg-in-a-hole wheels.  With all the ground running, I broke the pegs on a regular basis, ordering more from our hobby shop.  Wouldn't be a problem now, but I was pretty shy of tools back then.

The plane eventually went away, but I still have that cool flying handle.

Anyway, thanks for another trip down Memory Lane!

I have the engine for one of these , where did you get the control handle ? would love to make a setup for throttled flight so i can slow things down if needed !

They pop up on eBay from time to time. I paid a good sum for the privilege of no longer seeking one.

I plan on disassembling and scanning the parts. I want to see if this one is a scaled-down Roberts handle.
Maybe someone here has the Roberts one?? Care to compare notes?

I also picked up a couple of Roberts 3 line bellcrank assemblies, but they will need to be in the fuselage or in an exposed wing bay.

The handle may be used to fly a few times...then maybe off to another owner.

I somehow accumulated two of these handles, one NIB and one used.  I'm a little afraid of using them and having the brittle plastic break on me in-flight.

The Fearful Mark

I took mine apart. The line lugs are pretty substantial at about 1/4" thick.

Some possible inspiration Jim........



The model in the above photo was originally posted by CEF member "Duke" Johnson. It looks to be a Sig "Skyray" with a Cox .049 "Sure-Start" engine equipped with a "choke-tube" style throttle. Cox International has/had these available. Obviously an exhaust-throttle ring would also work.

There's more than one way to rig-up a 1/2A 3rd control-line to control an engine-throttle. Don't hesitate to give it a try.

Thanks Roddie!

I need to contact the builder regarding his handle, and the unit's critical measurements.

For reference, the J. Roberts Upright vs Cox "upgrade."it

roddie wrote:Some possible inspiration Jim........



The model in the above photo was originally posted by CEF member "Duke" Johnson. It looks to be a Sig "Skyray" with a Cox .049 "Sure-Start" engine equipped with a "choke-tube" style throttle. Cox International has/had these available. Obviously an exhaust-throttle ring would also work.

There's more than one way to rig-up a 1/2A 3rd control-line to control an engine-throttle. Don't hesitate to give it a try.

I found the CEF thread where I had saved the photo of Duke's model. There's some info. in his post that you might find useful. The thread-topic was for Cox International's Sure-Start style/choke-tube back-plate with throttle adaption, like the one in the photo. Different cylinder-types/#'s and the question of sub-port induction are also discussed in the thread.

The link was found in my J. Roberts 3-line handle thread.

https://www.coxengineforum.com/t3865p20-throttle-backplate?highlight=throttle

Jim. I don’t seem to have much time anymore to get on the forum, due to that work thing. Please excuse my language, that is a four letter word. But to my surprise, I received the notification for this thread. I might still have this plane. I made the bell crank, easy to do. And if I remember right, I did use the cox handle and the biggest problem was line tension with the under powered reed engine. It would be better to use a 049 TD with a carb. The skyray was just a simple build as a test bed. Of course you could pick a better flying plane, but the skyray isn’t a bad flying plane. Feel free to ask questions. I’ve flown control line carrier off and on for a few years.

[quote="944_Jim"]Thanks Roddie!

I need to contact the builder regarding his handle, and the unit's critical measurements.

For reference, the J. Roberts Upright vs Cox "upgrade. I think it is what it is for a 1/2A RTF not expected to last to long but an adventure into something new ?!?!? i DO SEE WERE A UPGRADE IS IN NEED Sorry .. isnt that J Robert for larger model tooooo ? Hay Duke !!

Hey Eric. Good to here from you. If you want a carrier/ 3 line throttle handle , I might have an extra. PM me if you want to buy one and see what I can find. I should have a few.

Hi Mr. Johnson. I appreciate your notes concerning the plane and it's controls. I'll go find the relevant thread where you showcased it before.

I'm thinking about running a Norvel Big Mig .061 on a 1960-ish Scientific Super Mustang (@25.5" WS)...profile fuselage, built-up symmetrical wing, and yes...an engine cowl!
The intent is to experiment with throttle.on 40' lines. Hopefully, this combination will pull an arm out of socket, yet slow down for tight stuff! I wanted to try sport flying with a throttle to see how it affected light stunt work.

For Getback...yes, you are right! The J. Roberts piece is for a much larger plane. The instructions show spots on the elevator bellcrank to shorten and drill for a smaller throw. There isn't a lot of detail on how much travel each piece moves. But, I do have 1/2A sized pieces now. Measurements will be taken and compared so I can built a smaller unit and handle. I've gotten to the point where I'm ready to dedicate handles and lines to respective planes.

Thanks for the input gentlemen!

Trying to get back into this...I used to have one of those COX handle/bellcrank kits, but that got lost in afire some 40+ years ago.
I still have a Goldberg Lil Wizard, and want to convert it to throttle like I did back then...I flew erzatz carrier with it.
I can go to a local library for 3D printer access, and would make it from more sturdy (maybe aluminum) once I've made the parts.
Any chance at this?

944_Jim wrote:I took mine apart. The line lugs are pretty substantial at about 1/4" thick.

OK, I'm going to try printing out and copying to aluminum and wood the parts you've shown. I can be devious....
Hoping this works!