I'm allmost finnised on my first gasser and I want to know what is the best ignition kill switch out there. or do I realy need one.

Im running a DA-50.

Are you asking about fiber optic (FO) kill switches? If so -- I like the EletroDynamics version and many like the Smart-Fly version...

http://www.electrodynam.com/cgi-loca...d81+1151491454

http://www.smart-fly.com/Products/Ignition/ignition.htm

Yes you shoudl have one... for safety sake... and also if your throttle comes loos in flight you can kill the engine and land... if it comes off mid rgane or above landing speed you could run out of battery before you ran out of fuel.

As Galen said...

I've tried both... they are basically the same thing.... I like Smartfly... Just because he also carries many other things I buy...

I agree, I always run 2 or 3 methods to kill my gas engines. 1. Use radio kill. 2. Use fiber optic switch to kill ignition circuit and 3. Have choke on a servo and you can close choke to kill motor.

R/C Foolish

I do the same and use the Smart Fly unit

I'm in the same boat with the other replies you've already gotten, I think a kill switch is a no-brainer.

I also like the three method approach, throttle cut switch on my tx activates the kill switch and closes the throttle below idle, and I have a servo on the choke.

I use the ElectroDynamics units so far, but I think that my next project will have the Smart-Fly since it can be built into a board that will handle other functions, i.e. regulators, power expander, etc.

I never use an electronic kill switch.
I have a choke channel (5) and switch, I also mix the switch to close the throttle all the way. If one fails, I have the other, it works great!

Some of you guys are missing the point of an optical kill switch. The really great thing with the switch is that the receiver has to be on and powered up before the engine ingnition will even be activated. Meaning, you can's start your engine unless the receiver has power. And, if for some reason, your receiver looses power in flight, the engine shuts down. You can have all the manual "hardware" installed i.e. choke servos, throttle servo kill positioning etc. but if you loose power to the receiver on one of these systems, you'd better hope your last opertating position of the throttle servo wasn't on full throttle.

Another good feature is not having to adjust your throttle trim every time you start an airplane. Many people use throttle trim as their "kill" mechanism. With an optical kill, just flip the switch. Now, the next time you go to start, your not fumbling around trying to find the "acceptable idle" position. It's where it was when you last flew.

I've been using Robert Richie's Smart-Fly for a couple of years now. I won't have a gas motor without one.

Thats the EXACT reason why I have them All the other methods are great as long as you have the power to use them.

Smart-Fly SuperSwitch looks exactly the same as Graupner GOLDTECH switch. Graupner only cost about 12 eur at local shop and they have heavy gauge wiring.

I just love the smell of fear.

How many ignition switches do most people have in a car. Aren't they dangerous too? In a full scale plane there's usually only one as well, provided you don't count the fuel shut of valves.

My opinion is that the trim lever on the transmitter and the fuselage mounted switch is enough for general purposes, and a steep dive will cure all the rest. Maximum safety can be obtained by not getting out of bed in the morning.

It's guys like you that cause clubs to lose fileds. These days all modelers should do whatever they can to be safe. If there are 3 options then you should use them, why not tell people that are asking for advice all of the options available? Maybe you can think fast enough to go into a good dive, maybe you have just been lucky or you don't care. John Murdoch, Zeeb, Josey Wales make the same point, use what is available or you can be like Geistware and yourself and close your eyes to technology.

This is just my opinion and maybe I spend too much putting a plane together but I fly at a filef that is surrounded by the public and I don't believe in taking chances with saftey. Granted that I have never had to use the extra kill features but what if?

R/C Foolish

I have had two occasions to need and use a magneto kill switch. Neither incident was serious because kill was available.

Recently I acquired an airplane that had a servo operated fuel line valve, which is another method for engine shut down. Fuel line shut off and throttle trim are not fast enough for emergency requirements in my opinion.

Bill

I like a choke servo, works for starting and stopping
I also leave my return spring connected.

I believe the AMA only requires an external switch to kill the engine.

Okay.. I saw a guy with a 40% plane at the 2005 Cactus Classic IMAC contest. Apparently either the motor mount bolts or the firewall came loose. Both the choke linkage and the throttle linkage bound up in the full throttle position. You could hear the thrashing of the engine trying to come off the airframe. We all knew it was just a matter of time until something really bad happened. A couple of minutes went by while he was trying to keep some assimilance of control. I'm sure it seemed like hours to him. Eventually, a loud crack or pop sound was heard. The engine seperated from the airframe. Good thing it was out over the field. Needless to say, neither the plane or the engine made it out alive. Had he had a way to shut down the engine, he could have safely landed and made the necessary repairs for a couple of bucks.

You can say what you want about mechanical linkages, but the norm is, if it can happen, it will. For me, the extra $50 is worth every cent knowing I have a positive way of shutting down my engines.

An old servo, salvaged nyrod and a slide switch should be less than $50. You must be using a sophisticated switch.

Maybe those unconcerned with people safety could buy into the redundant kill concept based on saving the airplane.

Bill

However much that list of items might cost... it certainly isn't MUCH less than a $50 Fiber Optic Kill Switch from SmartFly.

It's definitely heavier by at least a couple oz. and offers the potential for servo failure, switch failure and linkage failure.

Not to mention considerably more time in installation...

The last thing I want to do to my $2000+ plane is to install an "old servo, salvaged nyrod and slide switch"

Sure it works... but it simply offer more failure points than the SmartFLy...

And the real question then comes down to "Why?" to save $12 on a $2000+ plane?

There have also been some discussions on the wisdom of choke killing an engine... at high rpm and flywheel effect... some say there's propensity to bend the rod due to flooding a cylinder. I dunno... the the previous advantages alone are enough to justify the $50 optical switch.

I just got my smartfly optic kill switch. all I have to do is install it. SAFTY FIRST on top of my list to have fun on my hobby.

Good Choice! Install the Red Led somewhere..It comes in very handy

Maudib,

By no means was I attempting to change your preference.

The message simply was that a kill switch is not necessarily expensive. A positive kill method is important from a safety perspective. The method does not necessarily need to be fiber optic. A gas engine in a junk airframe is equally dangerous as one in an expensive airplane.

Bill

There is no engine made that would get a bent rod from killing it with the choke..

The only dead sticks I have ever had on my gassers is when I let a friend fly them and they hit my choke switch. Usually at about WOT. Never any damage caused by that.

Safety is alway important and many have commented about this. Now, how many of the people commenting use PCM (or similar) Failsafe for safety??

In relpy to your accusation of being one to cause clubs to lose fields, I think you could stand a breath of fresh air. As a club safety officer that uses a simply on/off electric switch for my gassers, plus a cut off idle carb setting, you seem to belive that my planes may not be safe enough to meet your standards. BUNK. Going a step further, my personal actions have gone a long, long way to saving at least one field, at great legal expense to me.

In 35 years of r/c, I've never had an engine runaway that was due to a failed method of shutting down an engine. I learned how to use a throttle lever a long, long time ago. I also know how to use a rudder and elevator stick when and if needed to kill a plane. Then again, I'm not so low on the income level that I fear the loss of a plane due to it's cost. I also won't be the one to hold my plane during a start or runup with a mechanical "stooge" unless chance of injury has been reduced to the absolute minimum.

You go your way, and I'll go mine. All my planes meet and exceed (in almost all areas) IMAA and AMA safety standards. My personal opinion is that if you're too afraid of what you do and can't bear the risk, be it mentally, physically, or financially, then you should not be doing it. There is absolutely nothing in this world that is perfectly safe, and some risk must be assumed by those that want to participate in any activity.

Weakness sucks!! I guess some people should only have desk jobs.

Pat

I have used PCM and failsafe on gas airplanes for the past 12 years. And redundant batteries for the past 8 years.

Bill

I lost two gas planes back to back last month and one might have been saved if I had a kill switch. All was going well until the muffler fell off my MVVS 1.60. I could not get the idle low enough to land the plane. Went back up and went into programming mode to bring the throttle ATV all the way down and that still wouldn't kill it. While waiting for the tank to run dry, the plane seemed to get pretty tail heavy and after a circiut or two, I lost signal and the plane went in about half throttle at a 45 degree angle. The assumption was that the RX battery came loose and then eventually disconnected. If I had the kill switch I would have gotten the plane down before the assumed battery issue took place. Would I have noticed if there was a problem with the batteries mounting condition for the next flights? Probably not. I will be putting a some type of kill switch on my next gasser. I doubt that I'm going to spend sixty bucks on one though. Just my two cents.

Marty