Ok, I'm new to gassers, so forgive the stupid questions that are likely to follow.

Just ordered a Brillelli 40GT (out of stock till the 15th ) and I have a question concerning a cutoff. Do I need to get an external cutoff switch and servo or is there a way that the EI interfaces with the receiver that allows a remote cutoff?

You'll have a separate battery pack with a seperate Rx type switch for the ignition module. The switch should be mounted externally so you can shut the engine off by killing the battery power to the ignition module. You can also set up the throttle servo so that it kills the engine just like you do on a glow engine. Do not use metal linkages between the throttle servo and the carb.

Bob

I've been curious about this as well. If you use metal throttle linkages, does the vibration create RF noise that interferes with the receiver, or it is something more complicated that that?

Yes any metal on metal vibration in your plane will cause interference. This is why a proper range check should be performed with both the engine running and not running.

You should also do this with an FM receiver so that you can see what is really happening.. a PCM receiver will mask some interference.

On a gas engine 99% of interference is caused by vibration. Most people think it is RF from the EI, but that is rarley the case.

For gas a nylon throtle rod is the rule. It is mainly because the steel rod could cause an RF problem. Seperation of radio components and engine components is what you want. A nylon rod isolates the engine from the radio system.

You can also hook up a choke servo with a linkage rod. Then configure your TX and put that choke servo on a switch, such as the landing gear switch. Then when your ready to start the engine, just flick the switch and turn the prop through a few times to prime the engine. Flip the switch off and then your ready to run.

If you need to shut down the engine--in an emergency--just flip the choke switch on and it will choke out the engine and kill it in about 1 second.

Then you've got 2 ways to kill your engine from the TX. One way is to pull the throttle stick and throttle trim all the way back. You should set it up so that this will definetly kill the engine. If that servo fails, or won't kill it for some reason--then you flip the choke switch and kill it. If that don't work, start yelling to let other flyers know you have a problem---- and try to plant it out in the grass--away from the flight line and pits. Better to kill a plane than a person.

Another way to do it is to buy a Grwat Planes kill switch. It's a microswitch. You just wire it in the positive + lead on the battery switch for the electronic igniiton system. Then use a small servo and a nyrod to push the switch off when you need it. Configure the TX and put that servo on a switch just like the choke servo. Set it up so that if you flip the switch--the servo pushes the nyrod and pushes the micro switch to a closed position. That kills power between the battery and ignition switch. Dead engine.

Another way to do it is buy a fiber optic kill switch that relies on the RX battery to maintain power. As long as you have RX power--the kill switch keeps the ignition circuit operational. If you loose the RX battery, the kill switch cuts power to the ignition system-- engine automatically goes dead. The fiber optic switch is designed to keep the ignition system ON as long as the switch has power. If the switch looses power--it shuts down the circuit and therby kills the engine. Kind of expensive--but easy to install. Plug and play.

Thanks for all the information, RcPilet. I knew that there would be a slider for the EI power, but didn't know if there was some sort of direct interface from the EI to the receiver (as opposed to using the mechanical switch and another servo). Seems like a good idea to me. Plug coming out of the EI that goes to a channel on the receiver. Set up that channel on a toggle...viola...remote engine cut-off as long as the receiver has power, which is just as good as the mechanical kill switch with fewer moving parts. Seems like a natural extension of an EI system.

NO, NO, NO, NO!

Never, ever, connect anything in the ignition system to anything connected to the receiver system.

(Unless you're using one of those fance optical remote kill switches)

Contrary to some, the electronic (or magneto) ignition really does put out a lot of high volysge pulses, the product of which produces RF interference.

Use a separate battery and switch for the ignition and keep everything separated from the radio system by 8", 10", 12", depends on who you talk to.

The more, the better.

What kind of range should you expect with engine running at idle and antenna collapsed? A better question is what range is acceptable? I am having problems with RF interference Everything ignition and receiver is at least 12 inches apart. I have done everything I can think if to fix the problem. There is no metal to metal, I have a nylon throttle pushrod. I routed the Receiver wire outside the plane as quickly as possible and I replaced the stainless steel pull pull system with kevlar. with all of that I get about 40 feet before the control surfaces start to flutter.

Range should be 75% - 80% of range with engine not running.

Check if you have a resistor spark plug. There will be an "R" in the model number printed on the plug.

Yep, it is a Champion RCJ7Y

Check to see if the aileron servo leads wind up closer to the ignition when the wing is in place.

Sometimes we don't count this when performing "the 12" rule".

Are your batteries touching each other? They should not be stacked together.

The Plane is the Aeroworks Yak QB so the wing wires exit even with the receiver. However, the plane gets the interference when the wings are not even attached. The Ignition battery and the Receiver battery are about 24 inches apart.

there is a photo of my receiver install on member photos. I couldnt figure out how to get a photo posted here. If you go to member photo gallery and then Giant and type "receiver" for key word you should find it

Wow. You don't have to shout. I'm just brainstorming here

Believe me, coming from the world of electrics I know all about separating electrical components from radio components.

But that is not what you said in your post. You said you were going to plug EI lead into reciever channel. You can not do that. That lead is for Ignition battery.

R/C Foolish

No, that's not quite what I said, at least it's not now I meant it to be taken. What I meant was have a separate lead coming out of the EI brick that goes to a built-in cutoff that can interface with the receiver. Guess I should have specified SEPARATE. i.e. one lead goes to the ignition battery, another one, properly isolated (if possible) within the EI circuitry that plugs into an active channel on the receiver that can be assigned a toggle swith on the Tx. Flip the toggle, kills the ignition.

This is not something, that I'm aware of, that is available today, and certainly not something that I would suggest someone tinker with. I would have thought that some EI manufacturer would have come up with something like this. Maybe it's not possible I'm not an electronic engineer. As I said, just brainstorming. Maybe give someone an idea that would make the modelers' life easier.

That sounds like the fiber optic electronic kill switch that Roger Forgues makes up in Canada.

I think it goes in series with the ignition battery and is controlled by the receiver.

Roger, are you in here somewhere?

Smart-Fly makes a nice Optical Kill Switch, I use it with success on all my gas planes.

DKjens

I use the Electo-Dynamics in all of mine as well. It does go in series with the battery and the fiber optic circuitry goes to an unused channel on your receiver. Works great and is readily available.

R/C Foolish