How to pick up a frisbee

[ThirteenOfTwo]

In answer to the original question...

I'd be very tempted to steal an intake from VRC Gateway. Those had to pick up cylinders (though those cylinders were much taller) and the intake design that ultimately emerged was efficient and lightning-fast. Rollers are king.

[pfreivald]

Originally Posted by MrForbes

Autonomous would not be the only advantage, but to me it appears to be the main advantage. Thinking of how many game pieces can be scored during a match, it's going to be a challenge for an alliance to use up all 45 in two minutes

I'd rather spend ten seconds picking up disks I and my partners just missed with and re-shoot them, than spend twenty seconds driving down to the feeder, getting fed, and coming back to score.

[MrForbes]

If you can figure out how to pick up 4 discs in ten seconds, then you definitely should be doing that.

[DonRotolo]

Getting back to the thread title, how does one pick up a disk from the floor?

If we postulate a bot 24" wide, we can put rails near the floor (high enough to clear field imperfections) both fromt and back that funnel the disks to a given spot near robot center. Then, when a disk is detected in the right spot, rollers on both sides pop the disk up a bit. Something captures the disk and sends it off for further processing, maybe a pneumatic cylinder kicks it forward or something.

The rollers would be somewhat small diameter so they can catch the edge of the disk, maybe with little fingers of tubing instead of a solid foam/soft surface.

[Tom Line]

Originally Posted by Speeder

I'm not sure that Autonomous would be the only advantage. Even if all the 'bots were able to score at an 80% average, that could leave ~25 game pieces on the floor if they stayed on the Field.

I suspect you will see much much higher accuracy in this game. The game pieces aren't highly variable, and from 15 feet away there is one magic rule for these frisbees: the faster you fire it and the harder you spin it, the more accurate it will be, and the less drop (or more rise) you'll get.

Go back and look at 2006, where you were shooting into a vertically oriented goal instead of trying to bank things in off the backboard. That should be a more accurate representation of accuracy, and top robots that year were absolutely deadly (85-90%).

Prototyping shooters is absolutely key (if you plan on being a shooting bot).

[Bill_B]

How about if the rollers were inside out duct tape, like a lint roller? Just put on a new "belt" for each match, maybe?

[gabrielau23]

Personally, I think that picking up frisbees will be a waste of time unless you can do it in under 15 seconds. Given that at the beginning of the match there are VERY few frisbees to be collected, the first minute or so should be a period when you aren't even using your collection mechanism. The last 50 or so seconds, the room starts to populate with frisbees. However, you still have the endgame to play. Plus since each alliance can use 17 frisbees, I doubt teams will be able to make 4 runs back and forth. @ 20 seconds a run, thats 80 seconds, or 1 min and 20 seconds elapsed in tele=op. you still have 40 seconds left. This isn't even taking into account problems like defense and unexpected stuff that just "happens". I think 20 seconds will be a very fast turnaround time near the beginning of the game. 30 seconds left people should definitely start going for the climb.

[pfreivald]

Originally Posted by gabrielau23

I think 20 seconds will be a very fast turnaround time near the beginning of the game.

Yup. The times I chose were somewhat arbitrary in illustrating my point:

To be a great robot you can't just do things well--you also have to do them fast.

[jimwick]

There is a video this morning showing a shooter that seems to be able to make shots consistently from 50 feet.
So... one strategy might be to park at your feeder and just try to pump in shot after shot.
But.... if you miss, having a bot that could pick up from the floor and convert each miss to a score might be a big advantage.

And another strategy might be to shoot from the feeder into your end zone, have your teamates pick up and score. Lot quicker than driving around.

[AdamHeard]

I wasn't saying their shooter isn't precise, it could be for all I know. Just a word of caution to people trying to infer off the video. They only show a few shots, and with camera cuts. This could be a perfect shooter, it could be a mediocre one.

Teams really need to prototype and prove this for themselves to be truly confidant in their ability to perform.

Originally Posted by Tom Line

I suspect you will see much much higher accuracy in this game. The game pieces aren't highly variable, and from 15 feet away there is one magic rule for these frisbees: the faster you fire it and the harder you spin it, the more accurate it will be, and the less drop (or more rise) you'll get.

Go back and look at 2006, where you were shooting into a vertically oriented goal instead of trying to bank things in off the backboard. That should be a more accurate representation of accuracy, and top robots that year were absolutely deadly (85-90%).

Prototyping shooters is absolutely key (if you plan on being a shooting bot).

Not only did they have higher accuracy in 06, but they were able to shoot MUCH faster than 2012 due to this.

[JohnFogarty]

One of my co-workers sent me this. The end of the video is more pertinent than the beginning.
http://www.youtube.com/watch?v=mDlHG...ature=youtu.be

[DonRotolo]

Originally Posted by Bill_B

How about if the rollers were inside out duct tape, like a lint roller? Just put on a new "belt" for each match, maybe?

I think you may find the glue loses its effectiveness after a few pickups, but definitely TRY IT. Dont take MY word for it!

Originally Posted by gabrielau23

Personally, I think that picking up frisbees will be a waste of time unless you can do it in under 15 seconds. Given that at the beginning of the match there are VERY few frisbees to be collected, the first minute or so should be a period when you aren't even using your collection mechanism.

You mean, aside from the 10 or more already placed on the ground, and the autonomous shots that missed? I think you are wrong, but please dont take it personally.

Originally Posted by AdamHeard

Teams really need to prototype and prove this for themselves to be truly confidant in their ability to perform.

Quoted for truth.

[DonRotolo]

Originally Posted by John_1102

One of my co-workers sent me this.

cool. I had seen that before, years ago, thanks for the reminder.

Just get something thin and flexible, like bumper cloth, hold it at the top and push out a thin sheet of something that rolls it out. Get under the disk, flip it up like a pancake, and repeat.

[nich]

One of the ideas that our team has tossed around is using some kind of vacume device to create suction in order to pick up the frisbee. We found that it took very little suction to do so. If you are using suction you can pick up the frisbee no matter what side is up. But we havn't discussed how to get the frisbee right side up in order to throw it yet.

[Lil' Lavery]

Originally Posted by donnie99

2. The rules state that you may block people at any point as long as they are not touching their pyramid, their safe zone next to the feeder station, and you do not pin them for more than 5 seconds. Although it would be against the spirit of FIRST and stopping the flow of the game, it is legal at this point in the season before any rule updates to block the feeder station. This is something that if seen at a competition, would most likely be changed for the rest of the season.

History would suggest the opposite. While FIRST has implemented many rules in order to encourage offense and protect offensive robots in the past few years, they haven't fully eliminated defense. Pushing and attempting to interfere with robot's transit across the field has been a long standing part of FRC games, and was a critical element in many games in which your alliance's human loaders are located on the far side of the field from where you score (2006 and 2011 being two recent examples).