Created this thread for peoples to share/build on ideas for ring pickup mechanisms for roundup.
So far we have:
I think the most important thing to decide when designing a grabber this year is how strategically necessary it is to grab more than one ring at a time. With one ring at a time, it is relatively easy to build an end effector on an arm that can pick up a ring. You can use the Vexplorer claw to build a grabber that grabs the edge of a ring. You can also build a simple roller claw, “spatula” forklift grabber, or a side pincher. Picking up more than one tube at a time is more tricky.
The second thing you have to decide is how important descoring is. If active descoring is of no importance, you can consider one of the dominant designs from FTC’s Quad Quandary, or you can make a “ring processor” style machine that doesn’t use an arm at all (also seen that year).
If you want to do everything, it gets harder. Possibly harder than necessary. It’s important to figure out exactly what is absolutely necessary and what function simply “would be nice” to have. Remember, optimizing your abilities in one aspect is better than being mediocre at all of them. And always remember to make sure your design is dictated by your strategy, not the other way around.
I’ll make a few bold predictions:
@ #2 the design that would make the typical #1 design obsolete is a efficient descorer as well as a high hanger (maybe some defence?)
that would almost guarantee a win
You might find this book entertaining
It details many of the top FRC robot designs from a year when “tubes” had to be picked up and placed on a scoring rack.
Of course there are many, many, differences between that game and the VEX game, but the two “Behind the Design” books are great regardless.
Jason
I think the differences between that game and this game are too great to be going to for references. Not only strategy wise, but what you were allowed to do/what you had to work with. You might find some basic holders in there, but nothing that will win this year’s game.
Guys…
FTC nearly mastered the pickup mechanism. I really think that this years winner will have a very fast and accurate way of depositing the playing objects.
And whoever does this will be smart enough to build their robot around the high hanging requirement. This means that they will pay attention to the weight and size of their bot.
_Cody
I think the fast and accurate part will be interesting - we had our first scrimmage this weekend, and were struggling to consistently score (we had a forklift, haven’t had as much time to develop the pickup as we’d have liked).
I also think that hanging at all will be interesting - I’m imagining the team successful at it will have an extremely sturdy, fast mechanism attached to a fast robot - blocking is going to become a major issue for teams trying to hang.
Wait… Gah! I really shouldn’t talk design but I will say that high hanging will depend upon one variable more than any other… weight.
_Cody
ya, unless you can do it fast, your opponents will get in the way
still think that the inside roller design is BEST for the score quick strategy, but not for hanging
Inside roller design isn’t really the best for scoring, you have line up pretty precisely (very easy to knock you off as well) and you can’t descore - something that I suspect will affect a number of results. This, of course, brings up the other aspect of hanging - while you’re doing it, what’s your opponent doing?
I think de-scoring is a face of the game that does not exist as much as you think it might. If you’ve seen some of the launch videos, JVN flips the goal and the tubes don’t really come off, and due to the umbrella shape of the top, I don’t think you’re going to pull any off.
As for the ability to aim, one can go back to the umbrella shape. If any part of the 3" inner diameter lands on the goal tip, the tube is going to sink onto the post, so you have a large room for error. You can also unload tubes pretty quickly. I would think it’d take a second or two to drop 3-4.
Go to youtube and look up the Quad Quandary game. That’s the game that’s the most similar to this game.
Well, we’ve successfully descored with a forklift, and I suspect the curve of the tube pretty much negates the underside of the umbrella, so I still believe that descoring is a viable and important consideration.
In how much time? Cause I can guarantee you that with a down the middle approach, the time it takes you to descore, a center roller arm can pick and score at least 1-2 goals worth.
And I’m not telling you to take my word for it. Go onto youtube, and even prototype these robots, and build your own opinion.
agreed
a teamate had a design that i thought was impractical
but when we made a prototype it was super effective
took just as much time as one would to score
Maybe not the best… 
better win ur first competition then
and i guess ill see the winning design on youtube
Hmmm… did someone say Polycarbonate?
Jason
We could descore in about 10 seconds, so yeh, about the same amount of time it would take for a center roller to score 1-2. The actual usefulness of descoring depends on the context - in this case it allowed us to own the goal.
In many / most / all item-collecting games, a quick, reliable, and “no skill” pickup has always been more important than how quickly you release the game pieces on a goal. Is this year different? Why or why not?