Throttle Control

Just a thought, I have been and advocate of throttle control in stunt for a long time. The new Spektrum DX6 Park Flyer radios look like the would be a great solution. They do not use radio frequencies and you could use 50 of them at the field at same time with no interferance. They use cell phone spread spectrum technology and each reciever is bound to one transmitter.It looks like a better solution than infared.
They would also be great for Carrier and Scale.

Dave,
That is something I did not know. As usual you always come up with a way to help us all. Thank you.

dick

>Just a thought, I have been and advocate of throttle control
>in stunt for a long time. The new Spektrum DX6 Park Flyer
>radios look like the would be a great solution. They do not
>use radio frequencies and you could use 50 of them at the
>field at same time with no interferance.

Of course, technically, they use a whole bunch of frequencies - just not much of any single frequency for very long.

I don't have much of a problem with the idea, but I do think it runs afoul of the definition of control line. I also would be surprised if you could ever get enough throttle response to help in the corners, although you could make adjustments between maneuvers (like with Windy's use of the Z-Tron).

Actually, Brett, the DX6 doesn't use frequency skipping. It scans the for one of 80 available frequencies, locks onto the first one it finds clear, then repeats the process for a second frequency. The transmitter and reciever are locked (Bound) together with a GUID. Between using two frequencies and the receiver only able to listen to the transmitter it is bound to, most all posibiliy of interferance is eliminated. All that aside, I don't see how throttle control would really help in controline stunt.

Allen Dye

>Actually, Brett, the DX6 doesn't use frequency skipping. It
>scans the for one of 80 available frequencies, locks onto
>the first one it finds clear, then repeats the process for a
>second frequency. The transmitter and reciever are locked
>(Bound) together with a GUID. Between using two frequencies
>and the receiver only able to listen to the transmitter it
>is bound to, most all posibiliy of interferance is
>eliminated.

If it has a continuous carrier, then you still have to have frequency control, do you not? Not to keep *your* receiver locked up, but to prevent everyone else's receiver from getting interfered with.

No frequency control is required. The DX6 transmitter "listens" to see what is on and then picks 2 free channels.
The rcvr then listens for it's transmitter and locks in.
It is not real spread spectrum, more of an automatic channel selecting dual channel system.
They use two channels to avoid dropouts in contact that can result from changes in antenna orientation.
Pat MacKenzie

The Spread Spectrum radios ARE radio control devices operating in the 2.4 GHz frequency band. This is the same band as cordless phones and a lot of other devices. The 80 frequencies alloted to Spread Spectrum R/C were chosen to not interfere with other equipment in that band.

The AMA rules would have to be changed to allow their use. Those rules are at least 40 years old, probably older, and were instituted to prevent CL models interferring with R/C operation. The advent of Spread Spectrum equipment says maybe the rule should be revisited. Although as noted their use in PA would be may not be needed, this would affect CL Scale and CL carrier, and any CL event that might use a throttle. It would certainly eliminate the necessity for insulated lines.

There are a lot of advantages to having throttle and or mixture control in Stunt.
The main one is safety – In an emergency the pilot can shut down and land. This would cover anything from a loose motor, spectator in the circle, sick pilot. runaway motor etc.
No more wasted flights in a competition from a bad setting, engine protection from lean runs. No more over runs, etc.
Add another dimension of control - i.e. more power for the reverse wingover then less power thru the loops etc. and more power for the square eights, verticals and overheads. Then less power for landing,
Power down to reduce of wind up in the wind.
And I’m sure other advantages will emerge as skill develops. There is even the possibility of new maneuvers in the future using throttle.

I purchased a Radio Shack "Zip-Zap" R/C car for $7 including transmitter. It has steering, speed control, etc.

When I build a model for it I will shoot the output up the control wires. I should be able to get speed control, flaps, and landing gear. Not bad for $7!

Why not allow change? When I started playing tennis in the sixties, Rackets were made from wood and had a hitting surface smaller than todays racket. Some Traditionalist believed tennis should not allow the newer materials and larger heads. Eventually, technology won. (for better or worse).

I looked up the latest rules on using Spektrum for CLPA Throttle control and sure enough somebody recently added in words to prohibit using "radio Control" in control line - I guess to protect AMA's radio frequencies.

"CONTROL LINE GENERAL

. 2. General - A Control Line model is flown on one or more steel wire line(s) or metal line(s) of equivalent strength, attached to the model in a manner providing aerodynamic control of the model's elevation through manipulation of the control surfaces during flight. Such manipulation of control surfaces, and any other of the model's operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety hazard to competitors or spectators. The use radio control to accomplish any control functions on Control Line models is specifically prohibited."

I can buy not using AMA's frequencies but Here is another job for our Phildelphia Lawyers - is Spektrum really radio control in AMA's definition. It is OK if you read the the preceding sentence that allows anything as long as it does not interfere with the control of any other model. Spektrum qualifies under this.

LAST EDITED ON May-07-06 AT 10:48 AM (CST)
 
Sorry, they are radio control devices and are prohibited.

The intent of the rules has always been clear: control of a control line model shall be accomplished through the control lines.

This was clarified during the last rules cycle because of the IR and optical devices some people were using.

You are welcome to submit a proposal during the next rules cycle if you wish.

EDIT: spelling, of course.

Ron King

>I looked up the latest rules on using Spektrum for CLPA
>Throttle control and sure enough somebody recently added in
>words to prohibit using "radio Control" in control line - I
>guess to protect AMA's radio frequencies.
>

I don't think it is to protect the frequencies - I think it is to protect the traditional concept of control line.

Free Flight has no pilot controls at all.

Radio Control uses radio to control the model.

Control Line uses wires to control the model.

A FF model with a radio in it is an RC plane.
Same-same Control Line.

"We could change the rules, but then it would not be cricket".

As if there's a difference between an electrical impluse through the lines or a transmitted one. They both use the same digital equipment, encoders, pots, and servos to accomplish actuating auxiliary controls of the airplane. The pilot is still controlling the flight attitude manually and hopefully keeping it off the ground until desired.

There is a huge difference. Signals sent up the lines do not utilize an RF carrier, thus they will not interfere with any RC operations.

>There is a huge difference. Signals sent up the lines do not
>utilize an RF carrier, thus they will not interfere with any
>RC operations.

I've always believed that these so-called "through the wires RC" systems are mostly CHEATERS.

They claim that they have "disabled the RF". But in reality, they are using RC with a fake dummy wire connected to the lines.

With modern, factory-assembled transmitters and receivers, I doubt that anybody could really convert one to "through the wires". Maybe back in the vacumme tube days.....

I've been a CD since 1980 and I could easily disable one of the "modern, factory assembled transmitters" by simply pulling the RF module out of the box. In fact, if someone showed up at a contest with one, that would be the first thing I checked.

There are commercial encoder/decoder systems available for control line use that do transmit through the wires.

Trust me, we have tried using RC with CL before. Back in 1980, I converted an old Sig Chipmunk (my apologies to Jim Van Loo) to use an RC engine, a stripped down Kraft receiver, Royal Mini Titan servo, and the smallest batteries I could find.

I flew it at the FARC field in Beltsville, MD and aside from the "whoopee" factor of starting the engine and launching without a stooge, the flight was equal parts hilarity and confusion. There is very little to gain by using a throttle on a stunt ship. Jockying the throttle during my flight was difficult and scary. On the second (and last) flight, I picked a reasonable setting and flew the whole flight that way.

We even went so far as to design a pylon for the center of the circle and considered using another servo for the elevator, but then we started laughing, asked ourselves "WHY?", and scrapped the whole concept. Flying a tethered RC plane did not have much appeal.

You would be far better off learning to set your engine properly and practicing the maneuvers, IMHO.

Ron King

The reason for the original post – the control line community should have the right under the rules to utilize and develop any new technology as long as it does not interfere with any other event. Recent rule changes resulted in needless restrictions on the new 2.4Ghz Spektrum radio equipment usage in control line. There appears to be no set to set interference problem with this technology. I do plan to sponsor a rules change to allow Spectrum type devices and look at a rewording to clearly allow infrared. Infrared should be allowable under this rule. Possible interference with another infrared controlled model on the field is a contest management problem – not a rules problem.

I fully agree with the sanctity of the manual control of up and down through the lines, but all else should be open to development. Something like 2.4Ghz Spektrum RC equipment opens up several possibilities for auxiliary controls in control line stunt, scale and carrier.
I do not agree with the “traditional” - auxiliary control thru the lines only argument. I have been a control liner since 1946. “Line control only” was never a valid reason, in my consideration, to limit auxiliary controls. It was sponsored way back by the RC groups, with good cause, to prevent overwhelming of frequencies. The restriction did not come from the control line side.
Bob Machado developed a successful tethered control line profile on a single line a couple of years ago that was completely radio controlled from outside the circle – He had up/down, flaperons and rudder as well as throttle. An interesting experiment, but not control line. While it was completely illegal it showed what can be done but it lost the main element - the feel of the airplane.
Current thru the lines auxiliary control systems are pretty much custom made, most are cumbersome, unreliable and not readily available. I started with insulated lines back in the 50’s motivated by Lou Andrews and his special event wins at the Plymouth Internationals using throttle. I flew throttle stunt some back in the late 50’s – after a lot of practice it settled into: full throttle for the wing over, power down for the round loops and inverted, power up a little for squares and triangles, power up for verticals and overheads. It worked but the insulated lines were a pain, they made it not worth the effort. Lou Andrews often said there has to be a better way of getting auxiliary control to the model other than the lines. Here it is, Spektrum, 50 years later.

Control line is not a dinosaur or relic that needs to be “preserved”. It is a viable and still developing sport and we should not put restrictions on it. We have enough “nostalgia” events to preserve things for the traditionalists.

Should we have outlawed - glow plugs, flaps, uniflow tanks, tuned pipes, fiberglass, epoxy, hot stuff, monokote, carbon fiber, foam wings and above all ARF’s? The main point is new ideas and equipment come along all the time and this is one that our people should be able to use if they want to without arbitrary rule problems.

Regards,
Dave Cook

If it gets to point where we need to buy an RC system and lobotimize it be competative, we might as well drop CL and fly RC.

I already have to make venturis and scronge for NVA's to get engines.

The essence of CL is to NOT mess with radio junk.

If you use JR radios you do not have to make any modification just use the DSC function and connect to the lines.

Back in the middle 1980'S, Larry Foster built a Rabe Mustunt II and installed three line throttle control in it. He flew it quite a lot. Jim hoffman flew it. I flew it. I'm sure there were other also. It was fun, but I think at the time no one thought it was any advantage for flying the AMA pattern.
Some of the objection was of course the big clunky JR handle necessary for the three line control. Maybe two lines with an RC unit for throttle would improve the "feel". Personally however, my feelings are that it would still be no particular advantage in flying the AMA pattern.
Developing "new" maneuvers that took advantage of the throttle, like hovering, stalls, etc might have some promise for some. Personally, if I wanted to do that stuff, I'd go back to flying RC and get into the "silly" game they call 3D, flying a $20,000 airplane like a helicopter.
I guess I've become too dogmatic in my "old age" but to me it just begs the question "WHY"???

I have flown almost all of the electronic control systems for CL throttle (JR, custom built handles, converted radios, Z-tron) control except for one one of the handles on the market.

The converted radios bypass the RF decks. The typical Radio transmitter has a encoder and an RF deck. That RF deck transmitts a signal to the RF deck in the reciever, then the decoder in the reiever talks to the servos. The converted radios I have in my collection bypass the RF decks completely and a signal and ground wire from the encoder is plugged into the decoder. The two wires between the encoder (transmitter) and the Decoder (reciever) can be 6" or 60 feet and still work. It sends a pulse down the wire, the width of the pulse determines the location of the servo arm.

While electronic controls for throttle may be a break from CL tradition it makes some CL scale models actually possible. A good majority of the scale models I have flown never would have worked with 3, 4 or even 5 lines. Some pilots I have flown with that were devoted to 3-line tried one of my models and switched to electronic controls the next day. The system I use send signals down the flyig lines and meet all AMA rules. I believe the spirit of CL is still alive since the elevator and format of the flying is still the same.

Land softly and enjoy the flying regardless of appearances

Fred Cronenwett
CL Scale and float flying
Wichita, KS

Fred,
I heartily agree with the use of converted radios for scale functions, where three line control just doesn't provide enough functions to be competitive. Four or five lines just represent too much complication and drag to be effective. Although I don't currently compete in scale, it would make perfect sense to me to allow the use of R/C equipment coupled with lines (for elevator functions only) for CL Scale.
The original premise of this thread was to use throttle control for CL STUNT and allow the use of RC to control that throttle to avoid the third line and the complicated handle.
My opinion was simply that I don't believe it would be any advantage unless the rules and the event was changed significantly.
I really don't want that to happen.

Added notes.
The main issue here is if anyone wants to run throttle they should be able to as long as it does not interfere with any other event. Rules should not arbitrarily restrict sny technology.

Also the throttle has been pointed out by a couple of people as being and advantage in running big 4 strokes in stunt. Reported to be more friendly and easily adjusted to suit conditions.

LAST EDITED ON May-11-06 AT 05:39 PM (CST)
 
>I guess I've become too dogmatic in my "old age" but to me
>it just begs the question "WHY"???

This "young whippersnapper" agrees.

I know im kind of stealing my dads words when i say this but i think it couldnt have been said better. When you fly stunt, especially for a long time. You develop a fixed rhythm, or cadence, or whatever you want to call it, by having a fixed engine run. You know how it feels if the motor is just a liiiiiiittle bit rich or lean...its just doesnt feel right. Plus an unexplained increase or decrease in speed is often a precursor of a bigger problem, and who knows how throttle control could mask those warnings.

I do think that there might be one or two advantages for throttle control, though mostly in the sport areas. Deffinitely not safety. If i look over and my pit-person is having a heartattack or something, why would i waste all that time pulling the trottle back , waiting for the model to slow down, glide in, roll to a stop, and go help the person? If there was something happening that was THAT DIRE that required immediate action, you better beleive that airplanes gettin' bellied-in without another thought!

As far as competition stunt, why make it more complicated than it already is? We practice enough and burn enough gallons (not me and not now at least ) worrying about size shape and bottoms and corners. Why the heck would you want to start worrying about throttle settings at the top of the hourglass and being in the middle of an official at the Nat's and worrying about my battery on my receiver dying at full throttle and flying the pattern with a runaway? If i had the ability to multi-task like that, id bring me a nice, cold drink to the circle with me and cannon-ball it in the overheads!!

Maybe these control systems have a future in scale and carrier, though i think there should be a bonus for "keepin it old school" and controling everything through the lines. Thats why I like this hobby is because the competitive edge doesnt rely soley on the evolution of technology. Coming from the first generation of CL fliers who grew up knowing what a gigabyte is and was walking around with his iPod blairing, its the simplicity of the system that is beautiful. Why change it?

(spelling at 3am is hard!)