Re: Team 1735 - Green Reapers Robot
 

the white rods in the front are pvc (.5'' i think). they smashed a ball into a field element/other robot to acquire.

Re: Team 1735 - Green Reapers Robot
 

Vivek --

We had "PAWS" that were pneumatically operated and worked beautifully in Atlanta. The main premise was based upon two arcs that curved with a 20" radius over the top of the ball. The arcs were mounted at a specific distance (determined via CAD) that extended past the apex of the ball as much as possible yet also stayed just barely inside our starting constraints. The mount point allowed us to not only "pounce" on the ball but also kick it off in the same motion when releasing.

The bottom part of the arcs were separate forklift-style arcs that played no real role in capturing the ball. In Atlanta, they were pneumatically actuated so they could be brought up and down as we saw fit.

The upgrades we did for Atlanta would have put us near the top in hurdling capability at our other two competitions had we thought of these ideas earlier in the season. The paws worked out really well, gaining us at least 1-2 hurdles every match in Atlanta (our elevator wire kept snapping which is why we only got one until 1983 suggested and donated some sailor's rope).

The time it took to capture the ball was dependent upon driver's skill, but once it was lined up it took less than half a second for the piston to close the paws and capture the ball. Pic to come later.

Re: Team 1735 - Green Reapers Robot
 

From what I saw at Hartford and battlecry, they were quite successful in doing so. There's no video of these events on TBA, but here's a video on youtube of the robot hurdling. The rods would flex enough for the ball to be acquired (by pushing it against a wall, usually).

edit: oops... I take a while to write responses...

Re: Team 1735 - Green Reapers Robot
 

217's grabber worked pretty well.

Re: Team 1735 - Green Reapers Robot
 

I heard about those guys.

Re: Team 1735 - Green Reapers Robot
 

Heh. :D

Although all of these posts have given me good ideas, what I really meant was stationary claws. If that makes sense. I meant claws that do not grab the ball mechanically (no powered grabbing besides pushing against the ball). Keep em coming please! I'm sure someone will get something out of this. Its mighty constructive and the pvc rod gave me an idea that just might work with only minor alteration to our bot.

thanks, vivek

Re: Team 1735 - Green Reapers Robot
 

I don't know exactly what you're looking for, but I know team Hammond (71) had an interesting method of pick-up. It is hard to describe but there are lots of videos of them on TBA.

This video has one point where it is easy to see there unique pickup.

Re: Team 1735 - Green Reapers Robot
 

Technically, 217's claw wasn't actuated in the classical sense to pick the ball up. They had a motorized shoulder joint and a pneumatic release. The potential energy contained within flex'ed PVC and extended surgical tubing is what allowed them to pick the ball up and keep it with no motorized components on the actual claw.

Re: Team 1735 - Green Reapers Robot
 

488 and 1778 and 2552 out here in Washington had claws like I think you are asking about. In the seattle regional 488 added another part to their bot that would hold the ball in from the top, but it still worked adequately before that at the Oregon regional.

You can see 488's alright in this one...
http://www.thebluealliance.net/tbatv...p?matchid=5363

1778 in this one, and the other team had the same bot as 1778...
http://www.thebluealliance.net/tbatv...p?matchid=5364

Hope it helps...

Re: Team 1735 - Green Reapers Robot
 

2593 was a very succcessful rookie. They had just two forks for pick-up(I don't remember off the top of my head how they did at the Boston regional, but at Beantown Blitz they were consistantly getting at least 2 hurdles a match)

16-here's a video (16 is on is the team with blue bumpers and a shooter)

Re: Team 1735 - Green Reapers Robot
 

Team 25 rammed the ball into their robot. No claw or nothing. Just a little arm to secure it.

Worked okay when their wasn't any defense on them. But as soon as the bashing began they had trouble acquiring game pieces.