Metal Shavings and RC don't mix

[Chris_Elston]

Just a quick note to the CD community...watch your metal shavings around your RC.

1501 fried our 2008 RC Friday morning at Boilermaker, but luckily took our 2007 RC as a spare with us. If you do this, make sure you have master code version 15 installed in your 2007 controller. You can check this within the first 5 seconds of power on, then quickly press the select button on your OI, and you should see U15 if your good to go.

What's ironic about this...was Digital Goats 829 handed us a safety flyer in our pits right when we figured out what was wrong with our robot after 3 crazy acting matches on Friday of stuff not working…on the flyer it said to "watch our metal shaving"...

I about croaked over in laughter, we had to laugh because it was crazy trying to figure out what was wrong….I am pretty sure we are going to frame it I think.

And just to let you know the metal shaving shorted out in the output pins of the digital I/O. Between the GND and +5V. By match #3 of our qualifying, FINALLY the RC Hardware light came on, it illumined yellow, and right where your main power connects, the RC was very hot to touch.

Then to later find out 1024 fried their RC as well in the finals at Boilermaker, really makes it a “spooky” weekend at Boilermaker for sure…

[chrisstruttmann]

Team Voltage got bitten by a similar scenario at the Florida Regional.
Delayed our inspection by about 20 minutes.

[Richard Wallace]

Originally Posted by Chris_Elston

...
What's ironic about this...was Digital Goats 829 handed us a safety flyer in our pits right when we figured out what was wrong with our robot after 3 crazy acting matches on Friday of stuff not working…on the flyer it said to "watch our metal shaving"...

I about croaked over in laughter, we had to laugh because it was crazy trying to figure out what was wrong….I am pretty sure we are going to frame it I think. …

The D-Goats' advice is good and they practice what they preach. I was one of the robot inspectors on duty in their row of the Boilermaker pits. When they found out, after a configuration change, that their 'bot needed to drop a pound or so, their first step was to cover the entire control system with a large sheet of plastic. Their second step was to set up a shop-vac. Their third step was get out the hole saw and go to work. No short-circuits for 829.

Other teams have skipped steps one and two above, and regretted it.

[whitetiger0990]

We've had issues with shavings in victors, but never with the RC. Ouch. We have a nice plastic sheet we use whenever we work on something which produces metal shavings, or any other kind of shaving. Always a good idea.

[Rick TYler]

When making metal shavings on a finished robot, make sure that your burnt offering to the gods does not include 'bot electronics.

[Tristan Lall]

I've got a semi-related question: does anyone know of a good way to straighten heavily-bent pins on an RC? Specifically, the digital inputs, after having been smashed with a robot arm (prior to the guarding being installed). That progressive damage due to a low-current short sounds like a worrisome possibility, if the pins are left alone.

[Qbranch]

Fire doesn't mix well with RC's either.

-q

[galewind]

hey, could metal shavings on the RC cause the Low +5v output LED to light up? I think that might be what happened to 1089's RC this weekend, too. We're going to bring our 2007 RC to Atlanta, and hope and pray we get our 2008 back from IFI in time.

[Alan Anderson]

Originally Posted by galewind

hey, could metal shavings on the RC cause the Low +5v output LED to light up?

That's a very common symptom of an unseen whisker of metal touching the RC's pins. All of the analog and digital pins have ground and +5 right next to each other, and shorting them together will definitely set off the low +5v detector.

[Al Skierkiewicz]

I had a robot in Chicago that had a metal shaving between two pins. It gave an RC hardware light that indicated that one of the 5 volt power supplies was down. The RC was also very warm to the touch in the one corner outlined above. Obviously, a 5 volt regulator lives under that section of the RC cover. The shaving was only noticable under a very bright light and I could not dislodge it with a paint brush. I ended up using the fine tip screwdriver of my Leatherman to move it out of the pins.
Tristan,
The pins on the RC can be bent to almost straight with a pair of needle nose pliers. Be very careful as the pins can be a little brittle and will break if you are too agressive. This operation is best done out of the robot under a bright light, at a table or bench. If you are coming to Atlanta and do not need the RC before then, just look me up and I will help you through a few of the pins. I am lead inspecting again, so you know how to find me.

[diesel]

Metal Shavings and Rc don't mix.
How 'bout soda and an O.I.

It happened to us Saturday morning at the Wisconsin Regional
our coaches fault, and it cost us a match.

[FRC4ME]

This happend to team 339 at VCU. When the problem first manifested itself, we noticed that we had lost 5V power to the geartooth sensors, causing the robot to slam into the opposing alliance's wall in hybrid mode.

The next match, we noticed that we had lost 5V power to the "disable autonomous" switch, causing the robot to slam into the opposing alliance's wall in hybrid mode.

After that, we saw the "5V output low" light on the RC. Unable to find the short, we had to use a loaner (from 2004!) for the rest of the day.

After returning from VCU, I held the RC up to the light and noticed a metal shaving under one of the digital inputs. Clearing it solved the problem.

[Blue_Mist]

Originally Posted by Chris_Elston

Just a quick note to the CD community...watch your metal shavings around your RC...

And that would be why our robot is shipped with a pink blanket. It's not just to comfort our robot as it endures hours of loneliness in the dark, enclosed crate, bumping over asphalt in a FedEx truck!

[Andy L]

We had problems at SV with shavings but they only made our RC Hardware light glow yellow until we got them out.