umm, you can’t exactly see it clearly here, but our robot is on the right:
http://www.chiefdelphi.com/forums/pictures.php?s=&action=single&picid=13029&direction=DESC&sort=date&perrow=4&trows=10&quiet=Verbose
and the wheels are expose but they’re essentially inside of the robot. would we still need guards over the wheels?
The rule has been there since Kickoff, It isn’t FIRST’s fault if the shooters arn’t gaurded. Our shooter wheel is mounted in a cage that will have screen door material (pet-proof Plastic stuff) covering it. So its protected from hits and fingers.
I seem to remember this subject in the kickoff video. The example used in the video did not have shielding but they used that as an example of something to consider.
As an inspector, I will consider a high speed spinning parts without shielding a potential safety hazard. As such, these robots will not be allowed to practice or compete untill they are safe.
What if they are spinning, just not fast at all?
This thread has been around for 2 weeks now. It talks about this Q&A and involves rule <S03>
Rule <S03>:
Shooter Mechanism must remain inside the ROBOT - Any mechanism used to throw balls must be
contained within the original 28” x 38” x 60”starting envelope of the ROBOT and must be shielded such
that the mechanism cannot make contact with other ROBOTs. A ROBOT that violates this rule will be
considered unsafe per <S01>.
It seems that the main problem with this new rule is the bystander part. Most robots are already sufficiently shielded to prevent spinning parts from running into another robot, but parts have to be somewhat exposed in order to do their job.
How shielded does it need to be to prevent a bystander hurting themselves? Are the bystanders being safe themselves? Our robot has some holes that you can get at the rollers through if you try. Would this be in violation?
I knew about the rule, but wasn’t sure of how much needed to be shielded…
http://i46.photobucket.com/albums/f104/Nita1190/Anonobots/Anonobots-41.jpg
Here’s my interpretation… If a robot cannot come in contact with it, then it’s probably likely that a bystander cannot ***inadvertently ***touch it. That’s the key word.
I think they threw everyone for a loop with the bystander part in that the original rule only states that it cannot come in contact with other robots. But I would think that if it’s within your starting envelope, and it’s not able to come in contact with another robot, then you’re probably safe with the bystander. Think of it as… if a bystander falls over, or gets off balance and accidentally bumps into it, puts their hand down and comes in contact with it, get hurts, etc… If not, then you’re probably ok.
Guess we’ll find out what the inspectors interpretation is.
Bystanders? what if your shooter wheel rips apart and pieces go flying? do you have enough shielding to keep nearby refs, ball spotters, camera crews… from gettting hit by flying chunks of plastic or metal?
can parts fly off your bot into the stands, where spectators are not wearing safety glasses?
what about the teams who stand next to the field during the matches? if your bot shooter self destructs will they be hit in the face?
I think that is what they mean by ‘by-standers’
In this picture, would the whole thing be considered the shooter, or only the bottom roller. The bottom roller is what gives the balls the “final impulse” so I would assume that that would be the only part considered the shooter and therefore the only part that needs to be shielded.
cause we all know that touching spinning wheels is the right thing to do to slow them down right!?!? =D
honestly i dont know how our team would shield our shooter w/o messing with the mechanics itself of the shooter aka having to redising
FIRST really needs to come out and define “gaurded” because like a lot of people said there are so many gray areas…
if you have like a box frame and the shotter is inlet about 6"+ is it no shieled so that a “bystandard” would have to REACH INTO the bot to touch it?..
so im still very mad about the addition to the rule… i think it can cause a lot of problems to a lot of teams very easily because i dont think the rule was well enough written on day 1…
Bottom line is this is an issue all teams will have to deal with.
How mad will you be if some 5 year old kid sticks his hand into a robot at a regional, or off season event, looses his arm, sues FIRST for $100M
and the entire FIRST organization comes to a bitter end?
In every engineering disciple safety is the primary concern, always.
Some of these robots with double CIM motor shooters - thats 1 HP available to the spinning wheels. Getting a hand or finger caught in a 1HP motor/mechanism would be very much like reaching under a running lawn mower and trying to grab the blade.
If you are talking about the bottom white roller, infact the entire mechanism you have there from the bottom white roller and the top white roller would be conisdered the shooting mechanism according to:
http://forums.usfirst.org/showthread.php?t=563
since the green strings are touching the ball while the final impulse is being applied. (This is all IMHO though, i could be wrong)
And to anyone getting mad about this rule:
This is a safty issue. Plain and simple. This years robots could be alot more dangerous due to the high velocity spinning masses, and with complicated systems to move balls. So its better to be overshielded than under IMHO
I’m just confused how, even though the mechanism works the exact same way as a gatherer as it does a shooter, it is “unsafe” when being run in reverse.
Well, here is a question for you, Is there any reason for the front of the robot not to have a shield? I dunno if you have a drawbridge or something im not seeing. But if you dont need that front part of the system exposed, i would just toss a piece of plexi over it to be sure.
Yeah, as Pete said in the beginning of the thread its not hard at all to zip tie some .02" polycarb film on any exposed part of the shooter. We will be doing this for sure.
I think it’s important to note that the rule hasn’t been changed. Despite what is stated in the update, “A good shield would prevent a bystander’s inadvertent little finger from being mangled…” (of course I’m paraphrasing), the rule says “other ROBOTS”. Nonetheless, I fully expect that we’ll have to add some kind of shield to the ol’ Fingerchopper ourselves. And if they really make lexan in 20 thou thicknesses, I think we’ll be fine. It won’t make our robot any uglier, that’s for sure.
As it is now, just wait and see, and enjoy your post-ship time dividend.
http://www.mcmaster.com/nav/enter.asp?pagenum=3369
Under the “Film” section. Looking at the specs for that thickness, I dont think anyone would have any problems with it breaking or sheering.
Kris,
They make Polycarb film in .005" thicknesses, too. We use a lot of the 0.020" polycarb on our robot. It is thick enough to rivet and very thin.
The only issue I have is the rewording. If they meant bystanders, they should have said bystanders on day one. My initial reading of the rule was they didn’t want shooters that acted like weapons. How can you shield the shooting part of a two wheel shooter?
Also, by actually having the shielding on a two wheel vertical shooter you can cause more damage. I have noticed that when I touch the wheels as they are spinning, they push my hand away (out from the center, which makes sense). If I had shields on the outside of the wheels, my finger would probably get stuck between the shield and the wheel.
We will do whatever the inspectors want us to, but right now our shooter is in the middle of the robot 5’ high.
-Paul