Car "cuts out" after big jump or hard hit (sometimes).

[i_r_beej]

when running at the local indoor track (carpet over concrete, so very hard) my car will occasionally stop responding after landing from a big jump or a collision with a wall, or a hard crash. It's not consistent, meaning that it won't happen after every single instance. The car doesn't respond to input from the Tx for a few seconds: no steering, no throttle. I've checked all wire connections and they seem secure. Unfortunately I'm unable to check if the ESC or Rx lights are still on. I've tried to repeat the effect in my shop by dropping the running car (sans wheels) onto the concrete floor with no success.

Since the car acts like it's not getting power, I suspect the ESC.

Any ideas? This is driving me crazy!

 

[X]

How electronically capable are you? I would suggest manipulating all the cabling to see if there are intermittent connections. If that does not yield any answers, it would be time to open the ESC/ RX and check for ring cracking on through hole components. Also in general look for intermittent shorts and loose components.

 

[i_r_beej]

I've repaired/re-soldered through-hole components on computer analog boards that were experiencing the "ring cracking" phenomenon you are describing. That was on the early compact Macintosh computers without an internal fan-- the thermal fluctuations caused an eventual cracking of the contacts. Stayed pretty busy for a while reviving old school computers.

While the car was running (I turned up the throttle trim on the Tx) I pulled and jiggled all the wires from the ESC to the battery and Rx. Jiggled the actual connectors, too. Nothing. I may open up the ESC and take a look. Although I plan on ordering a brushless motor system this next payday so this is almost academic. (But I'd like to have a fully-functioning brushed ESC for possible future use.)

 

[X]

Since what you describe seems to be a total power loss I would follow the V+ from the battery in line. It may be hard to follow if there are internal planes and feedthrough, but a multimeter should help you.

 

[xlDooM]

I have the same thing on my amp, but not often. I'm thinking maybe the ESC cuts out when the voltage ripple is too great, and the battery connector momentarily comes undone when it lands creating a big ripple. I once had the battery connection come completely off, so I know that it's wiggling on impacts.

 

[i_r_beej]

That's an interesting idea. I also wonder if the Venom "universal" connector might not be a factor since it's essentially TWO connectors plugged into each other. More connections mean more wiggle!

In any event, the issue seems to have resolved itself. At the most recent practice session and then a race the following week I experienced NO cutouts.