Safety inspection regarding open wheel shooters?

[HayWire1569]

After reading through threads here on Chief Delphi, our team (1569) is concerned about our open wheel shooter. What have been the difficulties regarding open wheel shooters, and which part of the wheels need to be covered to be considered safe?

I will also upload a photo of it tomorrow, or check out the video of our robot on YouTube.

[pfreivald]

Originally Posted by HayWire1569

After reading through threads here on Chief Delphi, our team (1569) is concerned about our open wheel shooter. What have been the difficulties regarding open wheel shooters, and which part of the wheels need to be covered to be considered safe?

We had no issues with our open-wheeled shooter at FLR... But our wheels are solid rubber 6" Colsons. I can't speak for others with different wheels.

[Jaxom]

Originally Posted by HayWire1569

After reading through threads here on Chief Delphi, our team (1569) is concerned about our open wheel shooter. What have been the difficulties regarding open wheel shooters, and which part of the wheels need to be covered to be considered safe?

I covered this from my Hub City experience in Al's annual inspection thread; see http://www.chiefdelphi.com/forums/sh...8&postcount=30 and http://www.chiefdelphi.com/forums/sh...5&postcount=32

Bottom line -- wheels got covered on every robot.

[Jeff Pahl]

Like many things, the answer is "it depends".

I'm sure I'll get to look at lots of unshielded shooter wheels in the next few days. My feeling on the subject is that any moving parts that extend outside of the mechanism such that they could catch clothing, hair, fingers, etc in the pits, or that could make contact with another robot or the field while on the field, will need to be enclosed. Obviously, you can't cover the part of the wheel where it makes contact with the disk, which hopefully is within the mechanism and is reasonably enclosed.

Again, "it depends" on the exact implementation of the mechanism in question and the opinion of the LRI at any particular event. I fully anticipate this being the "headache issue of the year" at Championship, and my advice would be to err on the side of caution and safety.

[Kevin Sevcik]

We're getting materials together to put a quick shroud around our small wheeled shooter at Lone Star. Some ABS sheet and a plastic bending heater strip. I'm assured it'll take all of half an hour to cut, bend, and mount the plastic.

[Gregor]

No open wheeled shooters had to be covered at FLR (us included), from what I observed.

[akoscielski3]

Originally Posted by Gregor

No open wheeled shooters had to be covered at FLR (us included), from what I observed.

you are correct Gregor. We never had to put a shirld on ours. In fact we use to have a shield over it but took it off because there were more pinch points with the shield. If you just have a wheel then you are less likely to get hurt, if you have a shield over it you have 10X more pinch points. If you were to put your finger (please don't do this!) into the shooter wheel at full speed your finger is likely to just bounce away, maybe get scraped. you may get your finger turned around the wheel a few times (as long as you don't have something across the wheel stopping your finger). If you were to have a cover that has holes in it then if you were to put your finger in it your finger would get pinched and broken off (likely). If you were to put it in between the tread and outside of the guard you will get your finger pulling in and ripped off. I don't see how putting a guard on your shooter wheel will protect you at all. Another reason we took it off was because while testing our tread ripped off from the guard and jammed up the shooter wheel, which if I left the shooter turned on the motor could have possibly burned, and possibly started a fire.

I don't see how putting a guard on can possibly make the shooter wheel safer... The only thing it would help with is stopping tread from flying out, which while on the field won't hit anyone because the field is enclosed.

[pfreivald]

Nobody even mentioned it to us as a possible concern at FLR. Then again, with solid rubber 6" Colson wheels on our shooter, the probability of their experiencing some kind of structural failure approaches zero.

[akoscielski3]

Originally Posted by pfreivald

Nobody even mentioned it to us as a possible concern at FLR. Then again, with solid rubber 6" Colson wheels on our shooter, the probability of their experiencing some kind of structural failure approaches zero.

We were never told it either, and we were running the new Nylon VEXPro Traction Wheels

[gyroscopeRaptor]

I would like to see an official response/Q&A from FIRST on this.

[Siri]

I don't know of any Hatboro Horsham robots that had to put on guards. We certainly did not.

I've Q&A'd a request for more guidance. (Not that I have overly high hopes) We're squeezing ounces, but we certainly want to be safe (and legal). A "finger guard" is doable if useful, but if LRIs feel that shatter guards are necessary, that could be some serious practice night rework (and weight). What is the guard intended to actually do, and how can it best do so while avoiding pinch points?

[Jaxom]

Originally Posted by akoscielski3

I don't see how putting a guard on can possibly make the shooter wheel safer... The only thing it would help with is stopping tread from flying out, which while on the field won't hit anyone because the field is enclosed.

The field isn't enclosed; that net would only stop a very big piece or something smaller by blind luck. There are plenty of people standing close enough to the field that they're in danger if something big kicks off the field.

No guard will make these wheels 100% safe; that's not the point. But if we prevent damage in even one case it's worth it, imo.

It would be best if the GDC had actually codified this from the beginning. They didn't, as we all know. It'd be good if they answer the Q&A, or if the LRIs come to a common agreement & publicize it. Hopefully that happens.

[Alan Anderson]

Originally Posted by akoscielski3

If you were to have a cover that has holes in it then if you were to put your finger in it your finger would get pinched and broken off (likely). If you were to put it in between the tread and outside of the guard you will get your finger pulling in and ripped off. I don't see how putting a guard on your shooter wheel will protect you at all.

You're joking, right? A guard with holes you can put a finger through is not a guard.

Another reason we took it off was because while testing our tread ripped off from the guard and jammed up the shooter wheel, which if I left the shooter turned on the motor could have possibly burned, and possibly started a fire.

Again, I hope you're joking. If the guard hadn't been there, that tread would have gone flying in an indeterminate direction. Wouldn't you agree that a fried motor is preferable to an injured student?

The only thing it would help with is stopping tread from flying out, which while on the field won't hit anyone because the field is enclosed.

The field netting is sized to stop frisbees, not nuts and bolts and chunks of wheel tread. Note that the robot is only running on the field for a few minutes at a time, while it's likely to see hours of use in the pit where no such netting exists anyway.

[flargen507]

We have been very worried about this recently, especially since our shooter has many reasons for possibly needing one. Our shooter wheel is one of the KOP wheels from last year with some tread bolted to the outside. It's a 90 degree angle shooter with no top and a rather large belt above it that powers the wheel from the CIM. Our wheel has spokes and sticks out about 1.5-2 inches out from the front of our shooter plate. Unfortunately, the shooter is in the bag with the robot and there are virtually no mounting points for a guard. Even if we could mount a guard, much of the shooter wheel would still have to be exposed. Would you not pass us through inspection because of this? (I ask this as we are currently working hard on a shooter guard, but I need to know if we should start going into to overtime).

[F22Rapture]

@Inspectors

What would your ruling be on this mechanism?

https://dl.dropbox.com/u/27736599/IMG_1263.JPG
https://dl.dropbox.com/u/27736599/IMG_1264.JPG

I get the feeling that I already know the answer, unfortunately...