Team Thrifty /Fifty Build Diary for Bitza

More problems!

For what reasons could the Error light on Sabertooth come on? The manual says Thermal cut out or Over Current but neither of these are an issue.
I just re-wired the whole robot thinking it was some dodgy soldering causing a short but the light still stays on. Furthermore when the error first came about, if I wiggled the power wires going to the Sabertooth (before the re-wire) the light went off. And now after spending a few hours trying to sort the problem my Brushless ESC has started making error tones.

It's all quite bizarre. The voltage reading at the power distributor is 12.3v and I recently charged the battery. If I wiggle the throttle stick the Brushless ESC comes to life, but the motor barely turns (actually appears to shudder backwards and forwards). Really quite stumped so any ideas would be much appreciated.

Thanks,

PJ

That's odd, your robot's behaviour is the sort of thing you tend to see in the arena after it's worked perfectly well on the bench!

Sounds like there's a bug in there somewhere. Either an individual component messing everything else up or a horrible little beastie circulating within your wiring intent on causing merry hell.
Best option might be just to take everything out, whack it on the bench, and systematically start replacing each component until it works again. I'd be inclined to say that there's something up with the battery, as although it seems to be charging and holding voltage fine, your brushless setup is lacking power and your esc is glaring at you which, if you're using a built-in BEC and the voltage is low, could result in an error light. Perhaps a duff connection or cell? After that, I'd say it could be worth inspecting/swapping the radio gear. But other than that..... :uhoh:

I think your right.

My thoughts are:

Dodgy Battery
Dodgy Battery connector (the only one I didn't change!)
Dodgy Rx
BEC gone on Brushless ESC

I'll gradually work through these and see what fixes it! I'm hoping this will also solve the blade problems I was having.

Quick update:

The Battery Seems fine
The Battery connector seems fine
The Rx seems fine
I swapped the BEC's over so I'm now using the one on the Sabertooth. This seemed to solve the problems with the Sabertooth Error light and now that run's fine (except one motor is runnig faster than the other now, so it doesn't go straight, but I think that's a separate problem)
I still get error tones from the Brushless though, and the motor still doesn't spin (instead just shudders around).
I ran the brushless ESC and Motor by itself, same. I changed the channel controlling the throttle on the Tx and again got the same. The odd thing is, the error tone is for Throttle stick not in bottom position but it is. If I then move the throttle up and back down the error tones stop, but I still just get the shuddering.

My thinking is either the Brushless ESC has gone, or the Brushless Motor has gone. They've had minutes of spin time though and nothing arduous. Any tips on how I could determine whether the motor or ESC has gone?

have you checked the soldering from the burshless esc to the motor?

Huzzah! The one connection I didn't check/change, typical...

Good spot Jonny. Hopefully that'll solve the Brushless issues.

The Sabertooth now has it's Error light on permanently so I really don't know what's going on there.

sabertooths have a built in boredness chip after some use the esc gets bored andf kills itself

Ah must be that..........

Just thinking about wiring up the disk on Bitza 2, I have a Relay and I'm hacking a servo, (thanks to some links I got given earlier)

But....

I can't think of a way to reverse the spin direction with this setup.

What would I need? And would it be worth while?

Bitza is invertible, so although we could continue running, being upside down may render the weapon useless.

I plan on hacking a Servo coupled with a Relay for our weapon control along the lines of this;

http://trebor69.tripod.com/speedcnt.html

or;

http://www.rc-airplane-advisor.com/elec ... oller.html

Except these examples use Mosfets, how would my set up with a Relay differ?

Thanks,