Retracts for stunt

[FLOYD CARTER]

This system for retracting landing gear for a stunter uses the lines to transmit the encoded signal.  However, lines are NOT insulated and can be twisted any number of loops, etc.  The technique is of my own design.  The encoder is part of the handle and the airplane electronics is installed in the outboard wing.  The model is a 62" span semi-scale Spitfire.

The electronics is a bit complicated!  However, the lines are NOT insulated, and the encoding technique is legal (not radio controlled, optical, infra-red, or anything else that radiates)

If anyone is interested in this, I can provide documentation, schematic diagrams, etc.

Please contact my e-mail
floydecarter@gmail.com

[BillLee]

The F2D guys have been using that technique for shut-offs for a couple of years. Encoded signal down the lines, a receiver that only hears its own encoding, and a mechanism (servo, whatever) that triggers a shutoff if the signal goes away. The source of the signal is in the handle, and they can terminate the flight with a switch there.  Seems like a similar thing could be easily used for terminating the engine run at the completion of a stunt flight. Very minor weight penalty for the shut-off.

Bill Lee

[PerttiMe]

The F2D guys have been using that technique for shut-offs for a couple of years. Encoded signal down the lines, a receiver that only hears its own encoding, and a mechanism (servo, whatever) that triggers a shutoff if the signal goes away.

Is that available commercially somewhere?

Sounds like it should work with electric power systems too.

[Dennis Adamisin]

Floyd:
NICE piece of work.  Are your retracts mechanical, pneumatic or electric? 

Is that available commercially somewhere?

Sounds like it should work with electric power systems too.

PerttiMe: Good call - I think the ECL'ers would be well served with the ability for a kill switch at the handle.

[PerttiMe]

I think the ECL'ers would be well served with the ability for a kill switch at the handle.

Or even stop and start switch. Retracts have to go up and down, so power could go on and off.

[BillLee]

Is that available commercially somewhere?

Sounds like it should work with electric power systems too.

Not sure. Will ask.

Bill

[Brad LaPointe]

Check out  www.technohobby.com.ua . or maybe Viko.Look in the accesories section for the shutoffs.Be careful you might find other stunt related stuff (Stalker engines).

Brad LaPointe

[FLOYD CARTER]

This system is now configured for retracts using a standard R/C retract servo and Dave Brown mechanical retracts.  The advantage over the Jomar system (it uses a microphone to detect when engine stops) is that the flyer can retract or lower the gear at any time during flight:  a definite advantage for precision landings.  Imagine, dropping the gear just 2 seconds before touchdown! 

The system can be modified to control a high current switch, or tapped into an electric motor controller for low level switching.

Although C/L scale flying is able to use insulated lines and multiplexed coding for multiple operations, this system does not use insulated lines, and works equally well whether lines are un-wrapped, or with lots of loops in them.

The main disadvantage is the total system weight of about 5 oz. including mechanical retracts, battery, servo and the circuit board.  That is why I'm using it on a very large stunter of 62" wingspan and RO-Jett 75 power!  A plane this size would typically weigh about 60 oz.  So 65 oz with the retract system isn't too far out of line!

Floyd

[PerttiMe]

hmmm, Technohobby has an electronic shutoff but no explanation what exactly it does or how it does it.
http://www.technohobby.com.ua/online-shop/en/electronic-shutoff-system-f2d

[Dennis Adamisin]

Floyd
5 oz penalty does not sound that bad - especially in a large hi-power bird like you are building.  A foot-less Spitfire sounds Awesome!

[FLOYD CARTER]

The Technohobby system is difficult to make out, and they offer no description.  However, from the fuzzy pictures, it appears that the receiver in the plane has a power transistor (good for switching high currents) and what looks like a solenoid unit with fuel line attachments.  That tells me that a power solenoid pinches the fuel line, and stopping the engine.

They show the unit attached to a F2D combat model. 

F.C.

[Bill Little]

hmmm, Technohobby has an electronic shutoff but no explanation what exactly it does or how it does it.
http://www.technohobby.com.ua/online-shop/en/electronic-shutoff-system-f2d

Hi Pertti,

Do you happen to know what currency the prices are listed in?

Thanks
Big Bear

[PerttiMe]

I have never bought anything from Technohobby but just looking at the pages it seems it is all in US$ but they'll accept payment in almost any currency.

I think many have bought at least engines from them, so will know better.

[Bill Little]

I have never bought anything from Technohobby but just looking at the pages it seems it is all in US$ but they'll accept payment in almost any currency.

I think many have bought at least engines from them, so will know better.

Thanks, reading the page in English is a nice feature! LOL!!  I just wasn't sure if the prices shown are in US dollars or Euros or...........

I have a project I just acquired parts for that could really use a rear exhaust Stalker in the .66 or .76 size.  Might be able to pick up a good used one somewhere (but probably not! LOL!!)  I have several .61 PAs but I have never used a Stalker in the big, RE style.  I have run a SE , plain bearing .46 and it is nice.

Bill