Control Lines For all you fly-by-wire fanatics!


Old 04-14-2007, 03:01 AM
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Default Throttles

How come control line guys don't put one more wire on for throttles? You could land and take off when you want and wouldn't need a helper. I figure one extra line in the middle of the handle with a finder trigger type throttle....

I haven't flown a CL plane since the mid '70s. I guess I should buid one just for fun.
Old 04-14-2007, 05:44 AM
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Default RE: Throttles

The Carrier event fliers typically use throttles and a third wire. Also many of the scale planes have throttles and sometimes even more operational features such as landing flaps, lights, bomb bay doors, retracts, etc.

Still when it comes to throttle in C/L there is not much real need for midrange speeds. Usually you want all the power an engine can deliver and still be reliable. As for low throttle In Carrier the basic goal is to slow down the aircraft to is to the slowest speed possible and still maintain control and also for high end for the maximum speed possible. These are two points on which Carrier is judged

Speed and other racing events obviously demand one thing... RPMs!

Stunt is all about smooth consistant runs with lots of torque.

Just plain old sport flying has been done with throttles as well. This is often where a lot of experimentation takes place

The J Roberts control line system was developed and marketed for the purpose of the three line control for C/L.

For more info on multifunction handles look here:

The downside of an extra line is extra drag and a little more weight on the inboard wing panel. Lose the extra line and you have more usable horsepower available from the same powerplant. Also with the extra weight and drag on the inside of the circle makes it more difficult to maintain line tension. Ya gotta have that! This means possibly more weight added to the outboard wing tip and also more rudder offset to help keep lines tight. The trade off to this is even more overall drag besides the extra line.

That said, You can if you want to! Its been done by plenty of others!

"I haven't flown a CL plane since the mid '70s. I guess I should buid one just for fun."

Yes, you should!

For more info you should check into these guys here: and click on Stunt forum. its free to join there and they have catagories that include Scale and Carrier forums. Anyone there would be glad to enlighten you.


Old 04-14-2007, 10:47 AM
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Default RE: Throttles

Here is a picture of my Cosair. It was orginally set up for RC but I modified the wing and added a throttle control for CL. It has an old Fox 40 on it and it hauls butt. You need to really hang on but it's fun. I use a set up to hold the plane when I first start the plane then release a pin I have on a light rope to release the plane for flight. That way it won't take off or run amuck before I get to my handle. I use a J Roberts handle. The plane has a lot of torque and speed that I don't have line drag to worry about and I very seldom run it at full speed, it will pull your arm out. I'll take off and then throttle back so it will touch down and run in a circle on the pavement. I will even let it come to a stop then I'll give it full throttle and take off again. I have the tail wheel bent so the plane will turn away from me on the ground. That keeps line tension. I have an old Sterling P 51 I do the same thing with.
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Old 04-16-2007, 11:54 AM
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Default RE: Throttles

All of my models have throttle control except for a profile cardinal stunt model that I bought for $20. Throttles are used for carrier, scale and other events that require the ability to change the throttle setting. Windy Urtnowski from the New Jersey area has even experimented with throttle control on his stunt models.

Think about this for a moment....

RC pilots very rarely fly a model without throttle control while CL models are very rarely flown with throttle control...why is that?

Obviously throttle control allows you to take off with realistic power up and landing under power. I have flown in tandem with other scale models with throttle control. I prefer to have throttle control even for my sport models.

THere are several choices for how to control the throttles:

1) Infra-red system - (check with Windy Urtnowski)

this system uses infra-red transmission to control a servo to move the throttle from idle to full power, the transmitter must be pointing at the model for this work and has a range of 100 feet or less.

2) Electronic controls -

these are done with two insulated lines that transmit a signal and ground down the lines to control servos for the throttle and other features. These are specialized electronics designed for CL electronics and do not use a radio frecuency

3) JR radio system with DSC -

This is similar to #2 but it uses a radio control system that you can buy off the shelf, install and fly for CL without any frecuency being transmitted. DSC is short for DIRECT SERVO CONNECTION. The majority of my models fly with this system. this system required two insulated lines....

4) Single channel electronics -

this is where you take a sevo driver and two inuslated lines and move the servo. This system only can operate one channel. Several of my models have this system..

5) JR roberts mechanical 3-line system -

Designed way back in the 50's, this uses a special bellcrank and handle that work as a pair to control the throttles. Popular with carrier folks this system only works when you have full line tension. The last model I had with this system dates back to 1990 when I converted to electronic controls. THe cost for this system is about the same as for the single channel system.

I have a book I wrote about CL electronic controls if you are interested.

Land softly

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