can I shut off nitro engine from a distance
 

Hello everyone, I have a nitro rc truck and i was wondering if there is any way i could possibly shut off the engine without touching anything in the car, so in a emergency when the car is far away from me i could press a button on the remote or somethig like that to shut off the engine. Thanks for any help.

There's these. I don't use them but some people swear by them. Could be a good thing in some situations. http://www.killerrc.com/product/bumb...o-kill-switch/ There's others. Google "rc nitro engine kill switch"

if your worried about a runaway do to low receiver battery or lose of radio signal you can run a fail safe. what that does is applies the brakes when radio contact is lost or receiver pack voltage drops below i think 3 and a half volts. it won't shut the engine off, it just brings the car to a safe stop.

Thanks, but I'm not shure my basic radio will take that. Also I'm worried because my first car took off and i'm sure it was due to something else not the radio or low battery since i was right beside it and it didn't apply brakes.

any other choices? Looking for something cheaper. I dont need any sensors for low voltage or anything like that. Also do you know the range of a 2.4 ghz controller. Thanks.

just because you were right there by the car doesn't mean the car didn't have some sort of electrics glitch. back in the 90's when we were using AM radio's on nitro cars weird glitches were common place. my nitro RS4 2 took off on me on numerous occasions. i had to walk all the way across an elementary school playground to go get it. the newer 2.4 gig radios are much better but i know guys who have suffered minor glitches with those (early spectrum radios every time. mostly seemed to be a range issue).

a fail safe goes inline between the throttle/brake servo and the receiver. and you have to program it (super easy to do) to apply the brakes when the radio signal is lost or receiver pack voltage drops to low (will also keep you from over draining a lipo receiver pack). a properly programmed fail safe will bring a moving car to a dead stop by applying the brakes and hold a stationary car in place until radio contact is regained or you change/charge the receiver pack.
they're your best bet for keeping a nitro under control should something fail and there only $20.

Thanks man i found one on ebay for 3.99 and for technical difficultys i'm going to close the idle screw and open it with the throttle trim and when i want to shut off the motor i'll close the idle screw with the throttle trim.

backing the idle screw out so the carb will close with the throttle trim will cause the carb to close and shut when you hit the brake.

True didn't think abuot that, I still want a way to shut off the motor remotely, any other ideas?

I wouldn't use a fail safe as a good chunk don't work right with 2.4ghz radios. Also some newer radios have them built into the RX.

Throttle return spring is probably the only fool proof thing that will stop a nitro if it loses power.

As for remote termination of an engine... only thing I could think of is you would have to fit a 3rd servo on a controller with a 3rd channel to press something (like a piece of plastic) into the flywheel's rim to cause it to stop moving. You will need a fairly beefy servo though to do it, and concoct some rig. Or maybe some kinda electric valve hooked to the 3rd channel in between the exhaust manifold, and the pipe.
But of the shelf no nothing exists to my knowledge as it would have to be tailored to every single RC due to different setups

ok so if i hooke up a random steering servo to make it touch the fly wheel which button would i use on the controller to make the servo do something?

you would need a 3+channel radio
if you have a standard 2 channel RTR radio nothing...

I dont know about that. Trying to stop a rotating mass spinning at 40k+ rpms will require alot of force from a servo and the engine internals will stress out. Maybe a servo blocking the exhaust will be a better option and cheaper.




If you have a multichannel transmitter and reciever you could use any channel thats not operating the throttle/brake or steering. For example if you have a third channel for the reverse or for a remote start you could pull those

I have a 4 channel reciever. No reverse or remote start. Is there any way to hook up a servo and use it to plug the exauhst without replacing the controller?

With RC aircraft. we've been doing this since the dawn of time. Nothing special to purchase. You set your low idle on the engine with the TX stick at the lowest point while throttle trim is about midway. Low trim closes the carb. Engine immediately quits.

It's not safe if you don't have a way of being able to kill your engine, no matter what you are operating. On the large gas planes, I run a redundant throttle kill - just in case one system fails.

Well I use a killer bee switch on my 1/5 scale two-stroke gas engine acts same as kill-switch; I use a 4 ch traxxas radio.
This alot cheaper than hitting a solid object, or a person.
But won't work on a glow engine; you might check what the Freeflight people for a shut-off on there timed engine runs.
They use a fuel shut-off device of some kind that used to a mechanical device, but maybe there's a newer electronic one.

yeah, I'm going to end up buying one of those nitro engine kill switches, ther about $60 including shipping. No matter what i do with the idle screw and trim it doesn't work. If the trim shuts the engine off so do the breaks. I need brakes. I'll go to the local hobby store and check if they have anyting good. If anyone can tell me if a bumble bee switch thing will work on my redcat controller? I have one channel left and my controler has the on/off switch the two revvers switches and the trims. Thanks for any help.

The only thing that will kill your glow engine, other than a blown plug, is a loss of fuel or air supply. Nothing else, An electrical switch will not do squat unless it stops the fuel supply or plugs the air intake in the carb.

If' you've got brakes attached to your throttle, that might not be a great situation. What if you want to reduce throttle and simultaneously applying brakes would be disadvantageous? Could cause a skid, rollover or any number of things in the wrong circumstances. Can't think of any logical reason why brakes should always be coupled to low throttle.

So we're back to the same place. Use your throttle servo to shut the carb. No air = dead engine. To ensure this, the carb must be completely closed. If you still need brakes, why not set things up so that they engage at that point?


Are your brakes acuated mechanically or electrically?

BTW, the old free flight models ran on a specific amount of fuel so that they would quit when it was consumed or had a mechanical timer which cut the fuel supply. Looked like a glorified mousetrap mounted on the side of the fuselage behind the engine with a clockwork wheel and arm around which the fuel line was connected. Dethermalizers were something else, They operated with a fuse and caused the empanage to lift at the rear to terminate a flight.

A photo is worth at least a million words. Have a look here and you'll see what these things are: http://www.freeflightsupplies.co.uk/timers.htm

Click "reply" once, post twice. Sorry for the snag.

i have composite disc brakes. all i want is to remotelly shut it off in a emergency not with a timer or something like that. The switches have a electric valve so they claim that when i shut off the remote the motor will quit.

The best option is to use a throttle return spring. In a lot of cases, you'll need a higher torque throttle servo to handle the extra strain of overcoming the return springs tension. Using a "kill switch" of sorts isn't realistic because (as has been said) the air or fuel needs to be cut off and almost anything that will do that will come with its own problems of adding complexity and parts to an already compact package. Gas engines are different because you just need to kill the spark to stop the engine.

That's what the throttle trim does! Perhaps you need to tell us what Transmitter you are using and IF it has trim adjustments. If it does, you adjust the throttle trim so the engine idles when the transmitter throttle control/lever is full off. You then pull the trim adjustment back which closes the throttle fully and kills the engine. We do this with our airplane engines. I think you need to learn a bit more about how your transmitter controls work.

Airplanes don't have brakes. You can't use the throttle trim to set your idle stop.

I'm afraid you are very wrong. First, airplanes can and do have brakes if you wish to add them but that has nothing to do with the issue here. Fact is a nitro engine will not run with the throttle barrel fully closed. Even the very basic transmitters have trim tabs for all functions and it is used specifically to kill the engine upon landing in the case of airplanes. This is too simple. You start the engine. Begin pulling back the throttle. When the engine begins to stop, Increase the throttle trim. Lower the throttle some more and repeat the process until the engine is at the desired idle speed with the throttle full off. Now decrease the throttle trim. Bingo -- the engine quits. Most programmable transmitters have a KILL switch that does this for you and all of this can be set up in the programming. You set the throttle trim for the desired idle speed with the kill switch up. When you pull the kill switch down the servo simply continues a tad more to the closed position to kill the engine. Yes -- you must pull the throttle closed and then activate the kill switch (or the trim) to kill the engine but it is already pulled back because the engine is at idle. If there is a runaway condition due to a radio issue, with a car, just like an airplane unless "Failsafe" has been programmed, the vehicle will continue run away. Obviously, if the throttle barrel cannot be fully closed because of the carburetor design, then this is all moot. This setup will kill a nitro engine far quicker than pinching off the fuel line. In fact it is almost instantaneous.

"This setup will kill a nitro engine far quicker than pinching off the fuel line. In fact it is almost instantaneous." That works well on a plane. Kills the motor every time you put on the brakes on a car because it completely closes the throttle. The throttle stop keeps the carb from completely closing and killing the motor. Look at how a car or truck is set up. It's totally different than a plane setup. Brakes and throttle are on the same servo. Brakes on a plane use another servo. I know how the plane motor kill thing works. I have several planes. Car throttle linkage is different than plane because you have the brakes on the same servo.