Engine On/Off Mix for Electric (Tow) Planes

[Alex]

Maybe some of you are already using this mix. To my knowledge, none of the electric pilots I fly with are using it except for the one who recently showed me the mix.

The idea is to pick a switch on your radio. When the switch is in the ON position, moving your throttle forward will run your motor. When the switch is in the OFF position, you can move your throttle stick, but the motor will NOT run at all. This is like a kill switch for electric motors. I find this to be a major benefit for safety, since we know what happens if you accidentally hit that throttle stick when the motor is armed. When I connect my lipo batteries to the ESC, I get close to those big props. Now, I put the switch to off, and I can connect my lipos with a piece of mind.

So here is how I programed my Spektrum Dx8 radio (I'm sure other radios will work similarly). On my radio, I use the switch labeled "RUDD D/R" as my kill switch for the motor:

go to Mixing on front screen

go to Mix 1

then mix Thro - Thro

set Rate -100%
+100%

SW RUDD D/R

Offset -100

This should give you the RUDD D/R switch control of your throttle stick. In the forward position the throttle is on, and in the rearward position the throttle is inactive.

By switching the minus and plus signs under "set rate", you will make the forward position inactive, and rearward on.

I will use this mix now on all my electric planes because of the safety aspect.

[Len]

Excellent safety idea Alex, thanks for posting that.

LEN

[Pilatuspc12]

Good idea, Alex. I have , unfortunately, had the experience of accidentally hitting the throttle stick and having the motor come on while moving my Monster Pitts with the AXI 5330/18 and the APC 20x13 prop! It was a very unnerving experience. So this is very good information to set up on my radio. Thank You.

Regards,

Randy

[csessa]

Alex: thanks for putting this up. I have been wanting to get some kind of throttle hold on my electric powered planes and just never bothered to figure it out. However, The instructions below do not work on a JR 9503. The best I could get was half power. So after some frustration, I decided to give up, BUT, there in front of me was a menu item called throttle curve. I thought it was only on helicopter models, but there it was on an airplane menu. So it is the same idea.

Go to throttle curve.

Select which switch to use for throttle off. I used the mix switch (rear right).

I decided that position 1 (switch toward me) would be the hold position. so select pos 1.

Set point L, point 3, and point 5 to 0.

save it.

now with the switch pulled forward the throttle is alway 0, with it back it goes from 0 to 100.

I guess each radio is different but this is a really good safety idea. Again, thanks for getting me motivated.

[Alex]

Thanks for posting the programing for the JR9503. Maybe we will get programing ideas for other radios over time, as well.

[Lou]

Alex,

On my EVO 12 I programmed one of my toggles as a kill switch and then put a small, rubbery plastic cap ( red in color ) on the toggle as a visual aid.

On my Aurora 9, I believe that you have to be on software release 1.07 and later, you can press the 'Plane' icon in lower left corner of the screen and that acts as a software kill switch.

At present, the A9 software release 1.07 and 1.08 can have a toggle set as a kill switch but it is a convoluted process and due to a bug ( my opinion and not Hitecs' ) the switch does not have its high/low - on/off state properly sensed when the A9 is powered up. This means that on initial power up the throttle is live, once the toggle kill switch is activated, the state is properly sensed. Obviously, I do not use this method and only use the Plane icon software switch.

[Alex]

Thanks for adding to our list of radios that can accommodate this safety feature, Lou!