Sporatic operation.. Bad ESC?

[Lessen]

Ok, I got a weird one here. I was out back with my son watching him play with his Wheely King. Just some general bashing here, you know.. run it into every fixed object there is

THE STORY

So he had run it into the house and it's nose up against the wall right.. So I tell him to back it up. I get no response from him. He's just trying to climb the wall. So I walk over and assist and to my surprise reverse isn't doing anything. Then I noticed that it is sporatically trying to go forward with no radio input at all. So I walk over to get the truck and it continues to try to move forward (technically up but you know what I mean). I picked it up and put it wheels down and it just darted away for a few feet and stopped. I picked it up and held it in the air as it just did this over and over. I tried giving steering and throttle input but it didn't seem to be registering very well at all. It would turn left and right but not at all in time with what I was doing with the transmitter. In the house we go...

THE DIAGNOSIS

Of course Tx batteries are the first to check. Pulled 'em out, put in some cells I new were good. Test. No improvement.

Next would be channel. Put in a different set of crystals. Test. No improvement.

Next is the truck battery. It's a 5000 pack and we only put about 10 minutes on it before the issues started. I knew it was fully charged so I didn't think this was it. At any rate I tested anyways. Pulled out the pack, put in my fully charged Intellect pack. Test. No improvement.

At this point I also need to make note that when I turned off the Tx outside the truck did nothing. Nothing at all. It just sat there. Truck on, Tx off, and it just sat there. Turn the Tx back on and it would start up with it's funny stuff. Anyways....

So I tried a different radio. I pulled the leads and put them into a spare Spektrum Rx and used my 3PK. Radio on. Truck on. No improvement. Now what is interesting is that in this situation when I turned the Tx off it did not hinder the sporatic actions of the truck.

so at this point I'm assuming the ESC is bad. Last week the truck stopped working and I realized that the fuse had broken. So I replaced it.. same type of fuse, same rating (30). This should not have been an issue but it certainly seems like the ESC is causing these issues.

Whataya think? Did I miss something?

 

[beason]

well it sounds like you have replaced every part except the esc in your testing. my first guess would have been the rx since it affects the steering as well, but you changed that with no results. i would disconnect the motor leads and see if the steering straitens up, then disconnect the esc all together and see if you get steering back. if your rx is powered by the esc you may have to connect a regular rx pack to it for testing.

i can't see the esc affecting the steering, unless its something to do with the power feed from the esc to the rx.

 

[Lessen]

i can't see the esc affecting the steering, unless its something to do with the power feed from the esc to the rx.

yeah, see that's exactly what I was thinking. The steering does follow my lead, but it's very sporatic and it doesn't hold. It's like the signal is off and on except it's not. My conclusion was like you said.. IF the power feed from the ESC to the Rx is bad. However, I didn't try disconnecting the motor to see if I get steering w/o interruption. I'll check into that...

*edit*

Good job Blake!

I disconnected the ESC lead from the receiver and plugged in a Rx pack like you said. Steering worked perfectly. Rx is definitly not the problem. Looks like that ESC is shot. That sucks, I wonder what would have caused it to go bad. I always watch him run his truck and I don't let him keep the throttle on when it's bound up. Maybe it just took one too many 10 to 0 hits? :shrug:

Oh well. I'm gonna pull a Novak XRS out of my Mini-Slider and put it in his truck

 

[Lessen]

XRS installed. works like a charm.

 

[beason]

what kind was the original? hpi? maybe they will warentee it...

 

[Lessen]

what kind was the original? hpi? maybe they will warentee it...

Just the stock ESC. They might, I don't know. I didn't put in a "stock" fuse when it went last week. Mostly because you can't find them. I looked all over the place online for a WK fuse with no luck. I just ended up at Sears Hardware. Oh well, I'm not gonna fret about it. Thanks for the extra assurance test :thumbup:

 

[flm_savage]

yeah that jolt is a pile-o-poop.

i have the stock firestorm esc for sale if you want (cheap). Its the SC-15 and worked for the 10 minutes i ran it.

 

[Lessen]

Thanks for the offer man. I'm good though. I put a Novak XRS in it so it's good to go.