I have tested my team’s robot for a few hours on tile at home, but when taken to the school for driver’s practice on an actual field, motors started to go out. Within a half-hour of practice on the field, two motors stopped working and they would only blink red. I did some research on the forum and came to the conclusion that the ports those motors were in had been blown out, so I switched the port and the motors worked fine again.
What I want to know is how can I prevent any more brain damage? I remember seeing something about using electrical tape on ports, but I don’t know exactly what that meant? Thanks.
In case it matters. Here are pictures of the motors that had the port problems(Dr4b and Claw).
I wouldn’t be able to explain why, but I wouldn’t be surprised if VEX’s bad crimping tool somehow increases the likelihood of killing ports. Your mileage may vary.
As said above, make sure cables are properly crimped and use anti-static spray.
I’d also like to add to shorten the cables as much as you can, and to eliminate as many sources of static as you can (For example, 3d printers running). I also found that a humidifier works well for dry rooms, but make sure it’s far enough away from the robot.
When you are crimping mark sure the wires are in the same orientation between connectors. For example if the yellow wire is on the left side of one end connector, then you need to make sure the yellow wire is also on the left side of the opposite connector.
The Cortex did not have any widespread disconnection issues related to ESD and generally had no ESD-related issues at all except when using IMEs. When using IMEs, sometimes the user processor would crash or the IME count(s) would be reset as a result of ESD. Nevertheless, VEXnet generally stayed connected under these circumstances.
Coming back to this thread because my mentor, who has a degree in electrical engineering, has a theory. She currently believes that, since the ports are connected in series, breaking one port damages others. The damaged ports then become more likely to fail.
With that theory, i’d suggest moving your wires as far from broken ports as possible to prevent more from breaking.
The ports on the V5 brain are separated into 4 quadrants. My mentor believes the ports in each quadrant are connected, similar to how the cortex was. Moving ports away from broken ones (and into a different quadrant) will move them away from any ports that were damaged around a dead port.
As of right now, it is only a theory. We are waiting to see if vex will replace our current brain before opening it up to confirm anything.
Thanks for all the help I followed these suggestions before my competition today, and I did not blow any ports. Vast improvement on 2 blown ports in an half hour
To be specific, I raised my brain further above the floor, purged all custom cables severely shortening most other cables, and applied tape around my motor ports.
I killed a port because i drove the bot on our field before we used staticide on it. With V5: YOU HAVE TO ANTISTATIC THE FIELD BEFORE THE ROBOT GOES ON THE FIELD.
*** we even antistatic the wheels once in a while, just to be safe. Don’t really care to lose another port.
