Two Dead Ports In 1 Day

I have just lost 2 ports within 2 hours of each other. The brain no longer recognizes any motors plugged into these ports, and motors lock up when plugged in.

Here’s what I know:

  • Both happened on the same motor.
  • Both happened on the same wire (Custom Length).
  • Both occurred just after putting on 4 inch Omni Wheels ( Motor is not on the drive train).
  • First time occurred without the robot moving.
  • Second time occurred with a different part of the robot moving.
  • The Robot has been used very little since starting the rebuild.

Any help on how to prevent this from happening in the future would be greatly appreciated. This is the 4th port we’ve lost in 2 weeks, and we’ve only used the brain for 2 months (was delivered at the end of last season, so it’s not covered under the warranty anymore).

Do I replace the motor? Wire? Both? If the issue is that it’s a custom length, anything we can do to prevent it? There are no standard lengths long enough for our use. Our next competition is Saturday so we don’t have much time to experiment.

All I can think of is static and friction

Any way to protect from static besides anti static spray? I’ve tried searching on the forums earlier, but couldn’t find anything.

I know of mo way other than anti static spray. Where did this occurr? What surface? (Or what surface the field was on)? Carpet caused more static. Could you send pictures too?

Both times occurred in the claw. The field is on a hardwood floor.

What should I post pictures of?

The robot

This motor is the claw motor?20191110_223446also is any of the wire exposed?

Yes, that’s the claw motor.

I’ve checked over the cable, it has no cuts along it and and ends are crimped without the wires exposed. It runs inside or along c-channel all the way down, so it shouldn’t be rubbing against anything besides aluminum.

I have no idea. Someone more experienced might be able to help you. Most people are sleeping (I’m a nolife) so give it until tomorrow

What my team has figured out is that after torching 4 ports, to prevent a port from being burned out, release static. The most effective way we have figured out to release this static without spending money (using anti-static spray) is to take a wooden ruler with a metal edge and to touch the robot a few times with the metal edge before handling it. Although weird, we have tried this with a multitude of other tools but none have been as effective as a wooden ruler. Due to this, we now carry a wooden ruler with a metal edge with us to all our competitions.

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I had the same exact problem at a comp two weeks ago, motor was doing the same task, what ports were you using out of curiosity

Lol our claw has burned ports 3, 4, 5, and just the other day, 11. If you use our technologically advanced ruler method, however, we discovered that the chance of burning the ports due to static greatly decreases.

19 and 17.

The ports killed before today were 14 and 15.

I burned ports 8 and 9

Just use a ruler to release static and your problems should be solved. Don’t use tools. Even though they have rubber handles, they don’t release static too well and if your bot is like ours, you will literally see the static jump to your finger when you reach to pick up the bot.

I don’t really think this case is static. Both times, the robot was only on the field for only a few minutes, with very little movement.

I’ll try that once I have either a different cause or a confirmation it is static. I only have 1 port in range of the cable, and not enough cable left to make a longer one.

Sorry, that you keep losing V5 ports to ESD. Unfortunately, this is a known problem.

The best method to prevent further port losses is to apply Antistatic Spray:

If you don’t have access to the spray, you could try to use laundry dryer sheets to regularly wipe the field and robot wheels, like this one:

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Thank you for the helpful links.

It’s not that we don’t have access to anti-static spray, it’s that no competitions in my region use it on the fields from what I am aware of. I didn’t know it was legal to use on wheels, i’ll make sure to do that.

I’ll also look into using Dryer Sheets.

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Have you tried plugging a radio into the port? It may just be a problem with the motor.