Exposed gears/chain

[pacoliketaco]

Hi everyone,

I haven't been super active in the FIRST community since I graduated in '09, but in the 6 seasons since then (and especially at the PGH regional this past weekend) I've noticed more and more robots have exposed gears or sprockets/chains. I'm curious as to how this is legal; back when I was competing it was very important that these pinch points be covered, to some extent. And speaking from personal experience when I caught a finger between a moving sprocket and chain, why is this no longer a concern? On a very large number of robots I've seen, I could walk right up, and stick a finger or get caught in exposed gears, with zero protection around them. I understand it saves weight to not cover them, but at the expense of safety? Just seems a little odd to me.

[robochick1319]

Originally Posted by pacoliketaco

Hi everyone,

I haven't been super active in the FIRST community since I graduated in '09, but in the 6 seasons since then (and especially at the PGH regional this past weekend) I've noticed more and more robots have exposed gears or sprockets/chains. I'm curious as to how this is legal; back when I was competing it was very important that these pinch points be covered, to some extent. And speaking from personal experience when I caught a finger between a moving sprocket and chain, why is this no longer a concern? On a very large number of robots I've seen, I could walk right up, and stick a finger or get caught in exposed gears, with zero protection around them. I understand it saves weight to not cover them, but at the expense of safety? Just seems a little odd to me.

I remember when this used to be a rule that was strictly enforced. You are right that it has gone away in recent years.

From a safety perspective, I think FIRST is relying on teams to put their own safety measures in place as guards. I can't speak for all teams obviously, but we have a "hands off" policy when the robot is on to prevent these sort of issues. You could walk right up and stick your finger in a robot that was on but that would be a breach of safety protocol.

Technically, even in the years 2006 - 2009 there we always ways a person could hurt themselves by intentionally putting their hand in or on a active robot (with or without guards).

That being said, lots of safety conscious teams will still design these sort of guards to protect their students. But suffice it to say, if you don't have authorization/permission/training to touch a robot (whether it is on or off) don't touch it.

[mastachyra]

OP's avatar checks out: Exposed gears.

Actual input: My team has exposed chain for the time being and we are working on a guard. I too am surprised they would be lax on this issue.

[Joseph Smith]

I agree that it would be a good practice to always cover pinch points and exposed chains, but many times it's just not plausible with the design of the robot. However, fingers should never be anywhere near pinch points if the robot is running or parts are being moved by hand- that's common sense. Clear communication between team members working on the robot should be enforced to prevent someone from moving a mechanism or enabling the robot while someone else is working near a pinch point.

[smart1]

We cover most exposed sprockets and chain where possible. This year we use a chain to run the lift so we couldn't cover the chain but we covered the sprockets. Normally if we don't we get dinged in inspection. It probably just depends on the inspector.

[Cory]

Following Rule #1 of "Don't be an idiot" will generally protect you from open gears/chains.

If you're not following Rule #1...well a guard probably isn't going to protect you either.

[jvriezen]

Originally Posted by Cory

Following Rule #1 of "Don't be an idiot" will generally protect you from open gears/chains.

If you're not following Rule #1...well a guard probably isn't going to protect you either.

It's the 'generally' here that is a problem. Most people want their fingers to remain attached with a more reliable assurance than 'generally'. The idiot is the one that presses enable while the bot is in autonomous test mode, not you with your fingers in the gears.

As inspector I've told a couple of teams to protect their pinch points especially when they are highly exposed on the exterior faces of the bot.

[JamesCH95]

OP - Pics or ban!

Seriously, show an example of what you're worried about, it will make the discussion considerably more substantive. You say "exposed gears and chain" and have one mental picture for what that is, the rest of us have our own metal pictures that might be significantly different from yours. We must have some common ground for a productive thread. A great comparison would be something that had to be protected pre-2009 to pass inspection and something that is unprotected post-2009 and passed inspection.

Originally Posted by Cory

Following Rule #1 of "Don't be an idiot" will generally protect you from open gears/chains.

If you're not following Rule #1...well a guard probably isn't going to protect you either.

See sig. for extrapolation of rule #1.

[GreyingJay]

They are definitely still checking for it in inspections, one of our first jobs on the safety inspection to-do list was to create a guard for the gears on our forklift and to create guard plates to cover our drive motor gearboxes.

[hunterteam3476]

Originally Posted by Cory

Following Rule #1 of "Don't be an idiot" will generally protect you from open gears/chains.

If you're not following Rule #1...well a guard probably isn't going to protect you either.

Our Inspector made us make chain guards at competition or he wasn't going to pass us..... Fun stuff....

[notmattlythgoe]

Originally Posted by GreyingJay

They are definitely still checking for it in inspections, one of our first jobs on the safety inspection to-do list was to create a guard for the gears on our forklift and to create guard plates to cover our drive motor gearboxes.

Did the inspector require you to add these guards to pass the inspection? Do you have pictures of your unprotected gears?

[Al Skierkiewicz]

Guys,
R8 dominates in this discussion. Inspectors will look at your robot as a potential issue for volunteers on the field and students who are working on or near your robot. Sprockets that are buried inside your robot frame or near the floor or very high may pose less of a threat than items near handholds, or the outside of your main frame. If the inspector thinks it poses a safety issue, they will ask you to come up with a method to protect all around your robot. For those of you who have never pinched a finger in your bike chain, it is nearly the same as a soldering iron burn without the smell. The difference can be that a soldering iron won't break your finger while a sprocket may.

[GreyingJay]

Originally Posted by notmattlythgoe

Did the inspector require you to add these guards to pass the inspection? Do you have pictures of your unprotected gears?

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.

[pacoliketaco]

Originally Posted by JamesCH95

OP - Pics or ban!

Seriously, show an example of what you're worried about, it will make the discussion considerably more substantive. You say "exposed gears and chain" and have one mental picture for what that is, the rest of us have our own metal pictures that might be significantly different from yours. We must have some common ground for a productive thread. A great comparison would be something that had to be protected pre-2009 to pass inspection and something that is unprotected post-2009 and passed inspection.

Sorry, I'll try to make this more clear. Several pictures that teams have posted, or in reveal videos, show things that seem like they could be dangerous to me.

I want to make it very clear that the following pictures are just examples, and I am in no way saying anything bad about these teams or their robots, this is a concern of the rules in general.

2015 robots: http://imgur.com/a/hIHRC

I don't have many pictures of robots 5+ years ago, but this website has a decent listing of some of them: http://frcdesigns.com/designs-robot/ There are a few with the exposed gears/pinch points, but it seems that more of the robot is covered. This might be due to the game/robot size limits, but it just seems like this used to matter more.

These are from '08 and '09, the first two pictures are from my own design/team. There's always a human factor in these robots, and it was fully my own fault I ended up needing stitches one year. http://imgur.com/a/vOKDk

[efoote868]

Originally Posted by Cory

Following Rule #1 of "Don't be an idiot" will generally protect you from open gears/chains.

If you're not following Rule #1...well a guard probably isn't going to protect you either.

While I generally agree with this sentiment, it won't work in the real world if you're being audited by OSHA.