I am going to fly Basic this season. I have been flying for 10 months and will fly a Extrme Flight Yak 87" with a DA50. My question is, do I haft to have a kill switch on my plane I can trigger with my transmitter or can I just use the idle trim to kill it? What exactly is the IMAC ruling here?

ten pillows

There is no requirement for a kill switch on your engine to compete in an IMAC contest. However, NOT having one is a REALLY BAD IDEA!!!! Spend the $60 for one. It is the best insurance you can have. There are times when the idle kill will not work and the consequences are dire.

just use a servo for your choke! kills two birds with one stone! acts as a backup kill (if your throttle idle trim kill doesn't work).
As a bounus, just flip a switch for the choke when you are priming your engines!

I am using a Futaba 9CAP. Can I just use the throttle cut switch to do the same thing?

ten pillows

If your throttle servo goes "belly-up", or your throttle linkage breaks, then no.
The idea is to have a seperate kill system
I use the RCCATS RC-100.
No extra servo, weighs almost nothing, cost about 25bucks.

The throttle kill switch on the tx is really the same thing as trim.... just it moves the throttle to a pre-set position

Thanks guys, I'll get a kill switch. I appreciate the help.

ten pillows

I use my 9Cap using the "idle down" function and the "throttle cut" function. I then have a seperate manual kill switch mounted on the side of the model.

Ryan

I have a smart fly optical kill switch connected to the gear switch of my JR8103.

Once again, if your throttle servo dies at full throttle in flight, how will you kill your engine? No amount of radio programming will fix this.

Hi Ryan. Say, you really do need to put an optical kill switch in your plane. I use the 9C and the switch on the top back left (l.g. I think) to activate the kill switch. I just purchased a JR 10X and use the same switch location for my new plane.

I use Electodynamic's optical kill switch but the Smart Fly is a good choice too.


Bobby

P.S. What's the first SC IMAC contest you plan to attend?

Hey Bobby, is Vicksburg going to have an IMAC contest this year?

Ed M.

Unfortunatly no. The club did not support an IMAC contest for this year. Also, we only had 10 entrants from outside so it wasn't much fun. I even went to the trouble to change dates so that the Jackson crowd could come and compete - but none of them showed up!!

There are two contests that are close by however - Prattville, AL IMAC contest on 30 Apr - 1 May and Shreveport, LA SHARKS IMAC contest on 12-13 Aug. Maybe you could make those. For other contests check out the IMAC sebsite at www.mini-iac.com.

Bobby

Let me get this straight....
The kill switch is used to turn off the engine if (an only if [X(]) the throttle servo goes haywire...
IMHO and in the few years in the hobby I would guess that the posibilities of this scenario are low compared to other scenarios such as
dead battery, frequency problems or interference, radio glitches.

So...
Is the kill swith any good in the above mentioned cases?

FWIW- I use a choke servo and a optical kill ( smart fly ). My engine ( ZDZ50) will not quit at the low throttle stop so I have got to use one of the other options. Both servos are in the engine box and absorb alot of vib and eventually one will fail, or a linkage. You hear about it alot.

I didn't want to take a chance.

I use the optical kill whenever I shut down the engine, as it is the easiest way for me.

I couldnt rig a choke bellcrank on my plane so thats why I used a servo.

The next plane should not need a servo choke so it will just have a smart fly.

With the Smart fly optical kill switch if you lose power the power to your engin modguel is interupted engin dies !!!!

And this is a bad thing??

I had a hitec 225 die on the throttle of my DA50 in my 2.3,this was at full noise in a vertical upline.Luckily i was running a fibre optic kill switch and was able to cut the engine in a suitable position to land without any dramas.A mate of minealso had a throttle servo let go on his ZDZ80.Vibration from gas engines can really kill some servos.

Guys,
I think the basic twist is you need two ways to kill the engine for safetys sake. Throttle trim is one, and a choke servo acts as two. Alternativly you can put in a switch to kill the igntion. How you control this switch is up to you. Optical, or even a plain old radio switch with a servo to turn it on and off works.
I don't know what the rules are, but the general rule is to have two seperate ways to kill the motor.

ALSO, please be sure to set your fail safe so if you turn off the TX (or loose its signal) you go to reduce throttle. You have a 50-50 chance of this being right if you don't check it, if you reverse the servo the default may be to full throttle, so be sure to check it.

Lastly, the kill switches only kill the motor if you loose power to the RX. In all cases this is a good thing IMO.
RickP

Now I thought there was supposed to be 3 ways to kill motor.

Switch to igintion battery
choke servo/optical kill
idle trim

You forgot the fourth......




Surface to air missile!! Every comp should have one!!