Hi, I know I tried to ask this recently when somebody mentions crashing and having the equipment go up in smoke.
Why isn't/or doesn't somebody come up with a switch or fuse that could disengage power on impact ?

Jim,

Fuses appear not to be fast enough to do any good. I suspect this is because a fuse with enough metal to carry the normal current has sufficient thermal mass that the short-circuit temperature rise that would blow the fuse takes too long. As one of the corollarys to Murphy's Laws says, the IC blows to protect the fuse

Now a switch might work if it had a actuating probe that stuck out the front, hmmm.. What to do about the prop??

John

Hi, I know I tried to ask this recently when somebody mentions crashing and having the equipment go up in smoke.
Why isn't/or doesn't somebody come up with a switch or fuse that could disengage power on impact ?

I know I have had some problems--not with burning up components but with the internal guts pulled out.

I am thinking in my case it was because I had set up the CC Phoenix (now that isn't a good name in this regard!) ESC for an "insensitive" cutoff, which means the ESC didn't actually cut motor power if it detected a current overshoot. I did it because I was originally afraid that when the current shoots up in a vertical maneuver, I didn't want the ESC to turn off the motor (shades of my glow experience!). Then I tended to forget about that setting.

Anyway after a lot of collateral damage to the wires and front end of my Nobler, I have re-enabled a "Hard Cutoff" and a "Normal" sensitivity to overcurrent, and I hope this means that if the current really overshoots, the ESC will cutoff the power before the motor/prop eviscerate my plane!

At Sig, the prop did mow a little grass on takeoff with my Vector (but didn't strike hard earth!) and everything kept running, so I am not sure when the cutoff kicks in. I'm a little nervous to check it out!