XXX-4 throttle issues.. ESC?

[sacktap]

Picked one up today at the local flea market. Brought it back home, charged everything up, and it half-works.

It is unknown when this car was last used. Weeks? Months?


Issue

Vehicle responds to throttle but it mostly twitches.
Demonstration: [ame="http://www.youtube.com/watch?v=uynUgKxC9jQ"]Team Losi XX4 throttle issues - YouTube[/ame]


Observations

1. Steering works nicely
2. After fully charging the battery, throttle still twitchy, but drove somewhat for 5 minutes. Now less responsive again.
3. The wires connecting the ESC to the motor get warm. This indicates resistance? However, I measure ~0.01ohms on both wires.
4. After recording the video above, the battery voltage was 7.44v.
5. What the hell is the beeping? Can't tell if its the motor or the ESC.

Possible causes

• Dead battery?
• Dead ESC?
• Dead motor?
• Transmitter? Seems unlikely. Used good batteries.

I have no experience with RC, but I'm handy with a soldering iron and I reeeally want to play with this thing already. I'd appreciate any help!

 

[Grave]

I see a RED Light display on the ESC come on when you try to apply throttle
That's a sign ESC is not setup properly
Twitching can be caused by low /dead batteries
Plugs for steering & throttle can be loose in recever in Rig check all plug connections

Did you get any Manuals with Rig
If you still can't get Rig to run I'd scrap the system in Rig for a new ESC & Motor Combo & pick up a new fresh lipo as well
Hope this info helps

 

[sacktap]

The red light comes on, but the (dimmer) green one does too.

I calibrated the ESC using the procedure here: http://www.teamnovak.com/download/instructions/pdfs/xrs_ins.pdf

I'll try finding a newer battery somehow.

Is it normal for the 2 wires connecting to the motor to both get warm? They are approx 3" long.

Will try to double-check all connections.

The guy I bought it from has a bunch of extra parts, I'll see if I can hit him up for some.

 

[sacktap]

I figured out how to calculate charge time, and realized I was not going quite long enough.

I also re-soldered the wires connecting the ESC to the motor.

The car definitely "runs" better now, but it's still not very usable/responsive:
[ame="http://www.youtube.com/watch?v=WR-pJ2-q6OY"]XXX-4: doing better, but still twitchy - YouTube[/ame]

Observations:

1. Motor gets quite warm, but not too hot to touch
2. One bullet connector can get too hot to touch removed it, soldered wire directly from ESC to motor, not any better
3. Battery wires near the connector get warm
4. Sometimes, without touching controls, car will start twiching (throttle + steering)

Possible causes:

1. Bad motor: read something about internal capacitors going bad?
2. Transmitter: steering works fine, but could it be the controller itself?
3. Bad ESC: maybe?

Bummer. I guess I'll call the guy I bought it from and see if I can get a deal on some more parts. Any suggestions on which parts to focus on?

Or how much to offer to a guy who acquired a bunch of parts and cars, yet knows nothing about them, even if they work at all?

 

[sacktap]

Tried a new transmitter, no luck. Thoughts? Motor? ESC?

 

[Greywolf74]

Hard to say...its gonna boil down to process of elimination. My first two guesses would be either bad receiver or a bad ESC.....could possibly be a bad battery. Could be something not wired up correctly.....wires shouldnt be getting warm without actually running the kit.