Exposed gears/chain

[notmattlythgoe]

Originally Posted by GreyingJay

Yes, and no, but I will take some at our next regional.

The forklift motor is mounted at the top of a lift frame and the gears were mounted on the outside of the frame so it was definitely a pinching hazard. We felt the drive gearboxes were one of those "well, if you really want to stick your fingers in there, you're asking for it" things, but better safe than sorry.

Thank you, this is good to know so we can have a plan in place in case we fall into the same situation.

[Fields]

At week 0 one of the inspectors (who is also the lead at one of the regionals) told us we will need guards for our robot to pass inspection.

We are just making a bunch of plastic disks that will slide on the axles on either side of the sprockets. They are large enough to extend past the chain and stiff even though they are fairly thin. They are held in place by the sprocket and either the frame or a collar. This way they spin loose on the axle in case you bump up against it.

Maybe I'll post pictures later.

[magnets]

Robot shields can present a false sense of security. You should NOT be working on a power up and enabled robot if you are concerned about safety.

I've had to deal with OSHA regulations this year, and let me tell you, the people who write these things have never used this sort of equipment in their lives. In some cases, OSHA regulations make equipment more dangerous - such as 'safety' shields that get parts stuck against grinding wheels, saw blades...

[Steven Smith]

The primary "OSHA like" regulation I'd use (as someone who deals with it daily) is lock-out / tag-out, which is sufficient for purposes of working on a robot.

I'm not actually saying to apply a locking device on the computer, but in general... but either by direct control (throwing breaker) or procedure, make it well known that robots are not to be enabled when anyone is working on them.

The bigger concern I typically see is just people getting too close to robots moving (whether it be a pinch point or just something moving quickly with lots of mass). It's particularly an issue on practice fields at events, with 6 teams + drivers + pit all standing around trying to troubleshoot an issue, with moving robots less than 5 feet away from them.

[GreyingJay]

Originally Posted by notmattlythgoe

Thank you, this is good to know so we can have a plan in place in case we fall into the same situation.

I panicked for a few moments trying to think of how we could quickly fashion a guard - we didn't bring enough spare aluminum, and I was starting to figure out how I was going to quickly cut and bend a U-shaped bracket out of Lexan... then we found an extra piece of coroplast we were using to mount our team number, folded that into the appropriate shape, added some self-tapping screws and voila! Problem solved.

For the drive gearbox cover plates we did cut some Lexan so we could still see what was going on down there.

[Andy Brockway]

I do not understand why there are more restrictive requirements at some regionals. Not able to compete because an inspector requires a chain guard?? How can this happen? I can understand a guard being required if a failure could cause parts of the robot to fly off the field but not a chain. No one should be touching the robot while it is running on the field.

[efoote868]

Originally Posted by Andy Brockway

I do not understand why there are more restrictive requirements at some regionals. Not able to compete because an inspector requires a chain guard?? How can this happen? I can understand a guard being required if a failure could cause parts of the robot to fly off the field but not a chain. No one should be touching the robot while it is running on the field.

Is the chain anywhere near an area your hand might be while carrying your robot off the field? Is that chain attached to a mechanism with a lot of leverage, and can it move while the robot is disabled?

[Al Skierkiewicz]

Andy,
I have to trust my inspection staff at events. If they ask that you cover a pinch point, it is likely that they are evaluating that individual robot based on past experience. I have seen things that would turn your hair grey and fall out. (Have you seen my picture?) As for some of the others, how many of you using chains can operate the mechanism without power? Can gravity cause it to move even if it hasn't ever done that? Can another person bump into your robot in the queue or on the floor and cause that mechanism to move? If you answered yes to any of these, someone is going to have a hand near or in your robot at some point.