Problem with Jags stopping unexpectedly

[Tom Line]

Originally Posted by wilsonmw04

Greetings,

I just wanted to give the group an update on our findings. During QCR, we replaced the jags with talons. This solved the problem with the controllers going into a fault state. We found that the fault state the jags were going into was a low voltage state. This worried me more than an over-current, honestly.

During our matches in QCR, we noticed we were draining batteries VERY quickly. At first, I thought it was normal since it is common knowledge that mecanum drives take a lot of juice when strafing. In some of the later matches, we were barely functional during the last 20 seconds of a match. We got a warning from the FTA that our measured voltage was dropping to 7 volts at the beginning of the match. This sent up red flags to the team.

At the end of QCR, we sat down and came up with some possible causes of our voltage issues:
1. inefficiency of our octocanum drive train.
2. An main power line (6 gauge wire) that was too long for the application and was spliced/soldered together. We built a new main trunk with main breaker that would be a straight swap once we got to worlds.

At Worlds, we cleaned up the slop in the drive train by realigning the modules and lubing everything. No noticeable effect. The main trunk was swapped out after our first match Thursday. The total length of the trunk was over three feet. Once it was replaced, the voltage issues disappeared and the robot drove very well for the rest of the event.


TL;DR: Keep your 6 gauge wire runs as short as possible. Create your own anderson connections if needed to keep from splicing the main line together.

I'm curious - was the wire or your wire splices getting hot? I'd expect it to if you were losing that much power to a resistance or partially open circuit.