Quote:
Originally Posted by Nuttle89
IIRC, even brand new Black Jags ship with the old firmware.
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Old firmware, new firmware, Jags shouldn't be used for drivetrains (in my humble but accurate opinion). A CIM will pull a little over 60Amps at "ideal torque", which is 150% above the rated Amperage of the 40A Snap-Action breaker. At that level, the breaker will draw that current for over a half-minute without issue. But the Black Jags with the OLD firmware will cut power at 60A after 2 seconds. With the NEW firmware, Black Jags will cut power at 93A. Okay, great, but old firmware versus new firmware doesn't really matter; the Black Jag will STILL cut power if the current draw exceeds 50A "for a short period". This is the "Progressive" software current cutoff in the firmware that isn't really documented anywhere except briefly on the website. Understand that the Black Jag was originally designed for use in applications where you don't necessarily have an external breaker protecting it!
We used Black Jags at Arkansas, and the robot's drivetrain felt very sluggish when starting from a dead stop or when turning (we kept slamming into the current cutoffs). For LSR we're dumping the Black Jags on our drivetrain in favor of Talons (who can handle 60A continuous and over 100A peak without the "progressive" cutoff), but we still are using Black Jags for other areas of our robot where we're taking advantage of the built-in limit switch connections on the Jags themselves; we can protect the robot much faster by killing the Jag directly than waiting for the software to get the message and do it for us.
-Danny