iceman11756

i was running my car with out the battery strap, and no body cover. i hit a bump and the battery flew out and the car stoped dead. now when the car gets 3 ft away it stops. It cant be interference from 3 ft b/c the steering still works. When i pull the battery wires, the heat sink that houses the battery/engine wires move around. I dont know if that affects the motor. Unless i follow it and hold my radio near the servo, its poop. WTH is wrong with my buggy

Takedown

My Feedback: (23)

It cant be the reciever becuase its feeding the power to the servo which is turning the front wheels so it might be wiring problems to the motor or it could be the motor.[&:]

BuzzBomber

My Feedback: (4)

That kind of sounds like the problem my co-worker was having with his rustler. His Hitec ESC kept cutting out intermittently as soon as the car was moving, and in the course of checking out the car, he noticed the heatsink was loose. On his ESC, the heatsink apparently "snaps" into place, and when it pops loose, you lose the throttle response because it creates an open circuit. Your heatsink shouldn't be moving when you pull the wires--check to see what's loose and you may find the source of your trouble.

ASSOCIATED_DRIVER

I did the same thing before, after the crash i put the battery back and the car wont move, but the front wheels still steers. What happened was the wire from the rx going to the esc somehow got pinched during the crash and broke the wire inside but is still connected by the wire insulation. I move the wires around and got the car running, but as soon as the wire moves inside the car because of vibration then it stops, I found the break in the wires and soldered them together and its back to normal.

I believe the heatsinks' puropose are for cooling the FET's only. You can run your car with or without it, the only problem if you ran it without it, is that the ESC will get hot and eventually shut off. The heatsinks does not close or complete or open a circuit.

On ESCs that have more than 1 heatsinks, the heasinks are separated, once they are connected then a short circuit is created, then the ESC is toast and warranty is voided.

Check your wirings, see if something got disconnected, also secure everything inside the car, nothing should be loose. Since you heatsink was loose, maybe your esc was just running hot and has activated the thermal overload protection, disconnect it from the battery and let it cool down, secure the heatsink and try again.

BuzzBomber

My Feedback: (4)

Associated driver, I agree with what you are saying about the heatsinks. I have just enough electronics experience to be dangerous and not enough to be useful. It doesn't make any sense to be running voltage through the heatsink, obviously, the heatsink would be electrically insulated from the circuit. Like I said earlier though, this particular hitec ESC doesn't work unless the heatsink is snapped into place. Whether by design or defect I don't know. It's probably something like you describe, an intermittent connection that becomes good when the heatsink pinches a wire. It makes me wonder though--In years past, I remember various electric airplane setups where you had to either insert or remove a plug to close the circuit--it was designed in as a safety feature to keep the prop from spinning up when you weren't ready. I was thinking maybe this ESC was designed so that the heatsink mount leg forces a spring clip connection closed when inserted into its mount on the PCB--this made sense to me when I typed it because it would be a crude form of thermal protection by not allowing the ESC to operate when the heatsink is removed. In practice, it seems pretty unlikely though. Sorry for dragging this off-topic a bit.

iceman, did you find out what's wrong with your car yet?