Banebots RS-775 Case Short

[Joe Johnson]

I've slept on this problem. To use the BB775s or not to use them?

I really want to use them because they should be a great motor. I think that isolating the case (from anything, including other BB775s) will limit the damage to that one motor. If I am using 2 in parallel (e.g. in a large arm application), unless both fail in the same match, I can limp through the match with only degraded performance as a result.

But... ...I don't like to go this way unless I have some way of detecting the onset of the problem and changing it at the first sign of a problem.

Has anyone tried monitoring the voltage on the case live while the robot is in action?

I am thinking that I could have put connect the case to a resistor network. For example, I could put two relatively high resistors in series between the battery and ground and tie the case to the middle of these and monitor this voltage. This monitor voltage (i.e. the case) would sit at roughly 6-8V (1/2 battery) unless a short starts and then it would start going rail to rail 12V - gnd - 12V - gnd - ...

And this is when I would replace that motor.

What do people think of this scheme?

Joe J.