Short in motor controller?

I don’t this has been around the forum, but has anyone ever come across one of these? I’ve been meaning to post about this, because this has happened around three times.

The most dangerous instance I can recall was during a normal day of programming, nothing being changed on the robot. I first noticed part of the drive wasn’t working, so I change the code a little and try again. Doesn’t work. I then smell something resembling burning rubber, and boom. The robot is on fire.

I lost the picture a while ago, but the fire burnt through the casing, revealing the burnt contents inside.

Any idea as to how the fire started?

ive had some 29s that didnt work but not catch fire, i think its a problem in your cortex the breaker should have tripped before the electrical fire started it would have to be a combo of your 29 and cortex… i think

it could have been the motor too we had a 393 that drew 8 amps before (we threw it away)

what type of battery did u have on it?

We were using 2 7.2v 3000 NiMHs at the time. I believe the motor came from a 269 on the drive? The drive was plugged into the power expander too. This has occurred on two of the microprocessors we have (cortex).

if the motor was plugged into the power expander the problem is in the power expander

did u have one battery in both the cortex and one in the power expander?

the extra current 1000 MA (1 AMP) of the new battery may have overheated the old 3 wire motor (i think thats what you are using according to the above statement) remember the 3 wire motors were designed to handle the old batteries that were 2000 MA and 1000 MA makes a big difference

You are confusing the battery capacity, 2000 mAh vs 3000 mAh, with it’s ability to deliver current.

Oh, meant to say the 2wire 269. Sorry.

your probably right