rwassell

Hi,

I have just bought a second-hand Baja Champ off Ebay.

Overall condition is reasonably good and it came with everything, including acoms radio gear, speed controller, battery etc.

However, I am having a problem and I am not experienced enough to know what's wrong, my worry is it might be faulty.

I turn on the radio.

I then turn on the car.

The first thing I notice is that wheels are skewiff. I use the offset on the radio control to try to straighten them but they're not quite straight still. I should be able to sort that by taking the steering apart and reseating the cog on the cam to make sure its aligned properly so hopefully no problem there.

The main problem though is when accelerating. The car will start moving forward and then cut out. I tried this without the top removed and you can see the led light up on the speed controller as I accelerate but then it goes off as it cuts out. I unplugged the battery and tried again, no change. If I move the accelerate controller very gently forward it will start to move and inch forward but when I push it just that little bit further, again, it will cut out. So even with the controller at full throttle, nothing is happening. The same thing happens in reverse.

If anyone might have an idea as to what might be wrong that would be really helpful, thank you.

Regards,

Rob

Eman77

A few thoughts:

1) Is your battery charged?
2) Did you try reprogramming the ESC, following whatever steps the manual suggests to set fwd/reverse/neutral?

What battery/ESC/motor do you have?

EXT2Rob

My Feedback: (1)

And what kind of battery?  NiMh?  Or LiPo?  
It sounds, from your description of the LED behavior, that the battery voltage could be sagging under full throttle, indicating a weak battery pack, causing the ESC to cut out, or, the ESC's Low-Voltage Cutoff (for LiPo) has been set.  Either could cause the behavior your describe.

rwassell

Great ideas thank you.

I will investigate and advise.

Thanks

Rob

pritch

I'm going to hazard a guess that it is a Tamiya TEU101~ esc in there - if so it is normal for the LED to go off when you accelerate.

It does sound like something is failing under load/draw. As the other guys have said first suspicion is the battery, especially if it is getting on a bit. Again, going to assume that it's a NiCad/NiMh pack. Are you charging the battery pack with a peak detection charger? Are you able to read its voltage, either through the charger or a multimeter? Does it charge ok?

Assuming that checks out next step is motor. Does the motor look dirty inside? Have you another motor you can test with?

I have known failing servos to cause this behaviour, but they are usually very close to death by then and it is rare. If your steering is working ok it is very unlikely.

You are correct about your steering - you can remove the horn and realign it. First reset the trim on the transmitter to zero, undo the screw that holds the horn on to the servo, pull it off the servo, then power everything on, and when the servo has centred, make sure the front wheels are as straight as possible then re-attach the horn so that it starts in as straight a position as possible. The trim on the transmitter will then take care of any minor adjustments needed after that.

rwassell

Thank you so much for such a detailed reply, you have been very helpful.

I won't be able to try these things until the weekend but I will go through everything as suggested.

I'll be back.

Thanks.

Regards,

Rob