2729 Safety

Hello everybody
I have a question on part of robot. The following pictures are of a giant sprocket that turns our turret.

http://img6.imageshack.us/img6/7739/robot1tq7.png](http://img6.imageshack.us/my.php?image=robot1tq7.png)

http://img407.imageshack.us/img407/5759/robot2sv1.png](http://img407.imageshack.us/my.php?image=robot2sv1.png)

Oviously the area between the two sprockets would be considered a pinch point but do you think the edge of the sprocket being exposed would constitute a safety violation prohibiting us from playing?

:ahh:

thats absolutley the biggest gear i have ever seen on a FRC robot:ahh:

if you enclose it somehow it should be fine, like make a “ring” to go around it

That would depend on a number of factors, including but not limited to:
–placement of nearby supports
–speed of turning?
–where in the robot, i.e. is it near an edge?

If you think there is a pinch point, shield it. If it’s near an edge of the robot, shield that, too. Bring more shielding to your first event to deal with issues the inspectors raise, which we may or may not be able to see.

Those are gears. not sprockets.

Definitely shield the pinch point where the gears mesh. A think sheet of lexan will suffice.

I can’t say about the edge, if it is sharp, how easily it can be touched, etc., but again a thin sheet of plastic cut in a ring that sits just above the gear teeth but hangs over them maybe an inch should be pretty good. As the wise Eric H wrote, bring materials to make shields should the need arise.

Well the original design called for a chain so it was supposed to be a sprocket but the chain did not fit.

The outside edge is maybe 2 inches on either side from the perimeter. It is powered by a window motor so I seriously doubt speed will be an issue with the huge gear ratio.

As for sharpness I think it would be pretty hard to cut anything on the edge but it certainly could give you a nasty poke. I figure we could sandwich it with pieces of plastic. Thanks for the opinions.

Sandwiching with plastic would certainly be a good idea, with extra near pinch points like the drive motor. Also add some extra near the sides; it’s not uncommon for a robot to tip that far, depending on how high this gear is.

Good Idea

funny society we live in. If you think it will be an issue you could always stick a square of lexan over the offending area and suspend it from standoffs from the crosswise pieces.

<R05> Exterior or exposed surfaces on the ROBOT shall not present undue hazards to the team members, event staff or GAME PIECES. Reasonable efforts must be taken to remove, mitigate, or shield any sharp edges, pinch points, entanglement hazards, projectiles, extreme visual/audio emitters, etc. from the exterior of the ROBOT. All points and corners that would be commonly expected to contact a GAME PIECE should have a minimum radius of 0.125 inches to avoid becoming a snag/puncture hazard. All edges that would be commonly expected to contact a GAME PIECE should have a minimum radius of 0.030 inches. All of these potential hazards will be carefully inspected.

So if the points are less than 1/8" radius, they should be shielded.