Smart fly optical ignition cutoff setup
 

I just got one of the kill switches from smart fly. Just a general setup question to make sure i have it right. I have the battery plugged into the switch, switch going to regulator, regulator going to ignition. I plug in the kill switch in between the regulator and the ignition box, correct? (I plugged in the kill switch inbetween the battery and the switch, and the light works, but dont think that is correct)

RE: Smart fly optical ignition cutoff setup
 

I went battery,switch,cutoff, regulator, ignition. there is a little bit of draw on the cutoff so it has to be on the other side of the switch so it doesn't drain the battery.

I am thinking of elimanating the ignition switch all together. The ignition will only work if the reciever has a signal. I also used Aux 4 as the channel on my 10X. This put it on a dial instead of a switch, this way it makes it more difficult to accidently kill the engine.

RE: Smart fly optical ignition cutoff setup
 

Ok thanks, I set it up as you mentioned, works fine now.

RE: Smart fly optical ignition cutoff setup
 

I'm not the safety police, but what would happen if your engine was running on the ground and you lost your receiver or Rx packs? How would you kill the engine?

-Tom

RE: Smart fly optical ignition cutoff setup
 

In reply to TT2. If you lose the signal or the power to the RX the Smart-fly unit will automatically cut off the power to the ignition unit.

RE: Smart fly optical ignition cutoff setup
 

I haven't used an ignition switch for a while now. I also have only used the optical cut off only once. The rest of my planes have gotten an RCATS standard relay cut-off. I have never had an RFI problem with it and its only $19 bucks.

DP

RE: Smart fly optical ignition cutoff setup
 

dp,
I have also used the RCATS ignition cutoff on several planes. Works great!
However, my son had a crystal go bad right after landing. The ignition didn't
cut off.
Bob

RE: Smart fly optical ignition cutoff setup
 

There are conditions in which no matter what the cut-off wont work! If the RX goes into a crazy state (i.e. the processor fails or some other catastrophic failure - but it retains power, the cut off will be rendered useless and the ignition will remain hot while the plane heads for impending doom. If the RX goes into freq lockout, programming the fail-safe feature to cut that channel would immediately kill the engine.

At a minimum the fail-safe should always be programmed to cut the throttle servo to a bit above idle so it can't fail in WOT under any but the most extreme circumstances. The kill switch should only be a backup.

In the case of the bad crystal, if the RX had fail safe and was programmed correctly, the engine would have at least cut to idle.

I never program my cut-off to change states in fail-safe. Bad enough I ever get a temporary lockout - I don't need a dead stick right after recovering from it!! I set my throttle fail safe to a high idle on lockout.

Of course all this assumes you have a PCM system or at least a programmable throttle servo (Hitec) .

DP

RE: Smart fly optical ignition cutoff setup
 

dp,
That was our conclusion. The rudder went hard right and the throttle went to high idle. It slowly rolled into the fence and broke the prop, no other damage.
Bob