ESC Disconnect for working on heli

[hobbystuff]

I have been flying planks for more years then I care to admit, and have been into helis in a big way for the last 6 months. One of the things that continues to concern me is how easy it is to work on a helicopter/airplane while the power system is live, and how easy it is to make a mistake.

Unlike gas/glow, an electric powered airplane or helicopter using an ESC with a built in BEC makes it dead easy to accidentally start the motor up while programming or adjusting the flight controls. I am VERY careful and it has happened to me twice with airplanes. Once I accidentally reversed the throttle channel - zoom, had to buy a new chair for the dining room table. The other I bumped the throttle and an airplane took a chunk out of my leg. In both situations I had just put the prop back on having removed it for "safety".

Even with the blades removed from a helicopter, there is still the potential for injury from paddles or the tail rotor. It would be better to use a separate Rx battery while working on the aircraft, but the bad thing is, often it is impossible to get a battery connected to the Rx or it is just a big hassle.

Now, I ALWAYS fly with a separate BEC since I had an experience once where a fried ESC left me with an out of control deadstick aircraft. The solution I use for airplanes and helicopters may have been presented before, but I thought it was worth showing again.

I think the pictures are self explanatory, but what I do is put a small JST connector inline with the BEC near the main power connector or another accessible spot. When I work on the aircraft, I simply plug in a small lipo battery into the JST connector and the radio system is powered up safely.

Just thought I would throw that out there, it works for me and has definitely saved me from doing dumb things while working on my helicopters.

[Snarf]

I use a short servo extension lead from the RX throttle channel to a point under the baseplate on my TREX 450. The ESC plugs in here for normal flying. If I need to work on the bird with power to the servos it is then a cinch to unplug the ESC and connect a 4-cell NiMH receiver pack in its place.

You can't program the ESC this way of course (I move the motor back so the gears are not engaged if I need to do this) but the ESC should be a "set once and forget" item.

BTW, don't connect your external receiver pack to the battery connector on your RX while leaving the ESC connected to the throttle. On my Spektrum 6200, the ESC tried to spin up the rotors when I connected this way. There was no where near enough energy in the RX pack to do more than turn the rotors gently but I am not sure if powering the ESC and main motor this way (through the servo leads) could damage the RX or ESC. Anyway - I got away with it.

Last point, for Spektrum AR6200 users, you can't use the throttle channel for binding. That HAS to be done using the battery connector on the RX. I still use the receiver pack for this but connect it into the battery connector and disconnect the throttle lead.

In this way there is NEVER a flight pack mounted in the heli when I am working on it indoors so accidents with the TX can't happen.