FastDoc98

I'm wondering if anyone can tell me how to hook up a radio-activated kill switch for my gasser. I have an FPE 2.4 with electronic ignition, and I want to be able to kill the engine from my radio. I bought the Tower Hobbies kill switch which seems to be made for gas engines with magneto ignition. The switches from tower only have a single ( + ) red wire to interrupt the power to the ignition, but I need something to interrupt the power from the ignition battery pack. I like Tower's little servo-actuated switch, but just don't know what to do about the wiring. Any one have any ideas?

Hobbsy

My Feedback: (102)

Doc, I just hooked one of those up on my Mustang 50, I'll check it out for you, and post back here in a while. Dave

KingAirJockey

My Feedback: (-2)

I just used a heavy duty jr on/off switch

bpryor

My Feedback: (45)

Hi FastDoc98,

I used one of those servo-actuated micro switches on a magneto ignition Zenoah a couple of years ago, and I assume it could be made to work on an electronic ignition, but I would recommend not using one since I've heard of many failures recently.

The two solutions I recommend are either the Electrodynamics(http://www.electrodynam.com/) fiber optics switch which is designed for electronic ignitions, but is expensive at $60, or a choke servo which then serves two purposes.

Bill

Big_Bird

My Feedback: (1)

FastDoc98, I'm not familiar with the Tower kill switch. However, here is a proven and inexpensive way to hook up a servo operated kill switch to an engine with a battery powered ignition system.

Ken

FastDoc98

BigBird

That was the wiring diagram I was looking for. The switch from Tower looks exactly like the one you described, I think even the product numbers are the same. Thanks for your help guys, that's what makes this forum great!

4 stroken ron

My Feedback: (29)

Why not just kill the engine by closeing the carb with the throttle servo? I have been killing all my gassers that way for years. It works for me.

bpryor

My Feedback: (45)

Hi 4 stroken ron,

>>Why not just kill the engine by closeing the carb with the throttle servo?

I think everyone does that, but the point is having a backup method to kill the motor. What about if the throttle linkage breaks, or jams? How about if you have radio interference that just affects the throttle? Don't laugh, this just happened to me, and it was the first time in ages I hadn't installed a back up method to kill the motor because I was trying to save some weight. The plane was within 10 feet, or less, pointing right at me as I taxied off the runway and the throttle went to full. I had just enough time to get it turned and take off again.... uncontrolled. Ok, you can laugh now. I was lucky and the throttle servo unlocked and I was able to land(quickly and roughly), but I wished I had had another way to kill the motor.

It wouldn't have been so bad in this case if I hadn't been lazy and not setup my failsafe settings. The default failsafe is last position, which isn't the best thing for the throttle. If I had set it up to go to idle for failsafe(as I usuallly do) it would have been a non-event. (FYI, it turned out I had a loose ground strap on the ignition causing the interference)

Bill

4 stroken ron

My Feedback: (29)

OK, that makes good sense. I guess I should go back and rethink my gassers to get a switch in them. No big deal I only have 2 to do.
Thanks
Ron

iflyrvs1-RCU

EMS also makes an optical kill switch for 39.95 that works excellent. Mike

Wings-RCU

My Feedback: (2)

I use a mini servo to the choke. Works great and will kill the engine as fast as an electronic switch connected to a servo. Use an open channel that is controlled by a rotary knob and you also get a remote controlled choke for starting. I'll never go back to a switch & servo.

Volfy

My Feedback: (23)

Doesn't AMA require a kill switch for gassers to fly in sanctioned events?

Wings-RCU

My Feedback: (2)

Volfy,
I'm not sure about AMA, however IMAA requires a method to remotely kill the engine. This can be anything including idle down as long as it will kill the engine.

AndySteere

My Feedback: (2)

I'm going with both a choke servo and the EDR fiber-optic kill switch on my first gasser (an RCS 140).

Nice thing about the EDR system is that if the RX battery or switch fails, the engine will be killed automatically. Same protection while in the hanger or travelling. Even if the primary ignition switch is turned on accidently... the ignition system doesn't have power unless the RX is also turned on. Should help prevent accidents.

Wiring diagrams and engine/ignition mounting pictures of my RCS140 are on my P-47 page at my website below.

Andy Steere
http://astro.umsystem.edu/andy/rc/

rc4me2

My Feedback: (13)

Thanks Ken! And everyone else as well. I am new to gas and did not know of these remote-kill requirements. I am installing an MVVS 1.6 in an H9 CAP. I am using the stock throttle arm including the idle stop. So I could not kill the engine via throttle (idle down). The engine has no choke, so I can't use that.

Fortunately, I found this thread and implemented the micro-switch/nyrod method. It works great.

I put my own little spin on the scheme. I have a Futaba 8UAPS TX with a momentary switch. I use this switch for activating the throttle-cut feature on the 8UAPS on my glow planes (just adds x% to minimum throttle to close carb).

For my gasser installation, I used a programmable mix from the throttle to channel 7. The mix is activated by the same momentary switch on the TX. The kill servo is connected to ch 7 and the mix is the negative of the lower half of the throttle movement. So at idle the kill servo has maximum mix (and thus kill-servo travel) to activate the micro-switch. At 25% throttle and above it does not have sufficient travel to kill. So you don't have to worry about an accidental activation in the typical flight power settings.

So it acts just like the stock Throttle Cut feature of the Futaba 8UAPS using the same switch. This is cool, because I already have the "reflex" of hitting the throttle cut momentary switch on the TX from all of my other (glow) airplanes.

Thanks for all the help!

jc

Vince

My Feedback: (1)

Be sure that you use a non metallic rod to connect the servo to the switch. It's OK to have a short piece of threaded rod at each end of the plastic rod.

Vince