My comments on shooters

[Richard Wallace]

Originally Posted by jgannon

... There are some inherent hazards, but like you said, you can't bubble-wrap everything. It's gonna be a fun season... I'm looking forward to seeing a lot of very creative bots (and maybe a few panicking FTAs).

I'll be one of the few panicking FTAs. And my own team will be among those that need close watching. They'd better shoot straight, or things could get interesting. See this video.

Oh, and all you drive teams, please put some velcro hooks under your controls.

Originally Posted by 2008 FRC Manual, Section 6.4.2 Player Stations

Attached to the Alliance Station Wall are three aluminum shelves to support the robot control systems of the three teams on the ALLIANCE. The support shelf measures approximately 60 inches wide by 12 inches deep. There is a 4-1/2-foot long by two-inch wide strip of Velcro tape (“loop” side) along the center of the support shelf that may be used to secure the ROBOT controls and Operator Interface.

[Tetraman]

Originally Posted by Richard

See this video.

DAAAAANG

We may need hardhats

[petek]

Originally Posted by jgannon

In a thread a few weeks back, Dave Lavery acknowledged that it's pretty likely that the scoring table will be wiped out by a trackball at least once this season ...<snip>... I'm looking forward to seeing a lot of very creative bots (and maybe a few panicking FTAs).

I was thinking of putting bullseyes on the scorekeepers, announcer and myself, like at a shooting gallery, but decided it probably isn't the show FIRST had in mind!

Seriously, we'll be watching for unsafe operation of all robots - whether they're shooters, arms or lappers. <S01> has a big footprint. As far as shooters go, I think it will behoove the drivers to be very careful about where they point that thing before they pull the trigger.

One of the things I like about Overdrive is the number of ways to score points and I'm hoping to see lifts, arms, catapults and lappers racking 'em up this week!

With regards to field reset safety and armed catapults, one solution I saw a team use that looked very simple and effective was to wrap a heavy-duty adjustable cable lock around the catapult and the robot chassis. McMaster sells this one (1033A31, $25.35):

[Brandon Holley]

While a shot trackball may cause damage...its not any more danger than the robots themselves. Robots are dangerous... This is why we take into account all of the safety measures that go with them. Some of these teams that are pushing 20 fps @ 120 lbs....THATS A LOT OF ENERGY.

I see how shooters can be dangerous, but I can see how every robot could be dangerous in some aspect. I think singling shooters out here in my opinion, is kind of lame. Sure they throw the ball, but being cautious from the beginning is going to keep everyone safe.

[ChrisH]

Originally Posted by Richard

I'll be one of the few panicking FTAs.

But Richard, FTAs aren't allowed to panic.

Dodge yes, but panic certainly not!

We're the ones that are supposed to be making sure everything holds together. We can't do that if we're coming apart. So be prepared to duck and cover the scoring system, but keep your head together. (At least until the ball takes you out)

[Engineer]

Will the FTAs be wearing body armor? LOL

[David Brinza]

"Robots will have to be built robustly to avoid damage from falling Trackballs."
-- 2008 Overdrive Animation.

There are non-shooting robots that can drop a Trackball more than 10' (Team 294: front and center!). An eight pound ball dropped from that height can do some serious damage. Balls dropped from that height can also careen off the field. Safety concerns about the kinetic energy of Trackballs will involve more than shooters.

I think the bigger concern is the risk of the shooter mechanism itself. Teams with shooters need to consider the effects of various failure modes (i.e. suppose this bolt comes loose, what if this bracket gets bent, and so on) and design accordingly. Team members should be prepared to tell the inspectors what fail-safe provisions are included to avoid injury to team members and people NOT familiar with the robot (referees, alliance partners, field reset, etc.). If your robot is a shooter, your "Release Safety Officer" should expect to get grilled on the contents of Update 5. Inspectors will not give much lattitude to a team that hasn't paid attention to safety considerations in their design.

[ALIBI]

Originally Posted by JesseK

You probably will not pass inspection if this is the case. If the inspector sees a system on your bot that has no way to slowly release the tension/energy or a way to physcially make it impossible for the system to discharge (even then you never know) then you probably will not pass inspections. For spring catapults, it's been suggested that you have a lock bar that physically disallows the mechanism to release. For pneumatics, you simply would discharge the whole system via the valve. If it's a combo system, well you'll have to figure out something. I'm sure the field reset crew will learn to ask teams to get the balls off/out of their own robots instead of doing it themselves.

Currently we have several possible ways to prevent a release. The best would be to launch with ten seconds left in the match with or without a trackball (I know, be careful where we shoot if not making a hurdle). The second is the mechanical stop used for the release, it holds very well, however there is always a chance it could release, it does not require any energy to stay put. The third is a bar that we push through the launcher and other support structures, this must be physically placed by a team member. The fourth is a very slow backdrive on a worm gear, this one has to be deactivated in order for us to launch and may not be practical to use while on the field, again, in the last five seconds we could reactivate it. We have several ways to prevent, slowly or quickly release the energy. I guess we will find out at our first regional if we have done enough.

[IndySam]

Originally Posted by David Brinza

I think the bigger concern is the risk of the shooter mechanism itself.

I agree with David. The biggest danger I see from shooters is parts coming off of the machines not the ball itself, especially on the stored energy machines.

Proper maintenance will be critical and I hope it will be stressed by the inspectors.

[Racer26]

agreed, teams will need to be closely monitoring their machine for stressed parts.

[petek]

Originally Posted by Engineer

Will the FTAs be wearing body armor? LOL

We didn't get kevlar FTA vests, but I'm lobbying for this patch for all field personnel:

[TubaMorg]

Originally Posted by petek

We didn't get kevlar FTA vests, but I'm lobbying for this patch for all field personnel:

Maybe we should lobby, instead, for a field mod. We should have a large lexan box around the field. You know, like a raquet ball court! Then we can convert Overdrive to 3D pinball

[Racer26]

3D pinball... oh dear, now you've given Dave ideas for the 2009 game.

[Engineer]

Just like when Casey Mears drove the Target car in NASCAR. You put a target on it and some one will shoot, hit, or plow into it. I think he got wrecked more times that he finished. With a patch like that on you, people will definitely take aim.

[EricH]

Originally Posted by petek

We didn't get kevlar FTA vests,

The denim in those things should be enough for a simple trackball, Pete. How many layers do they have with all those pockets?