Reaching for the Top Row?

[mwtidd]

Originally Posted by smclean1969

We're a rookie team that has some experienced mentors and one experienced student. It's a talented group with a healthy amount of prior training. We're having serious discussions about whether to shoot for the top row or just settle for hanging tubes on the middle and/or lower row. To reach the top row requires a more complicated robot design (e.g., extending arm, multiple piece forklift, etc...) and these seem a bit much for an experienced team, let alone a rookie team.

thoughts? Scott

One strategy that might prove good for you is the role of the fetcher. Design a small and really fast robot that can quickly and easily transport tubes from one end of the field to the other. I think the strongest alliances will have two hangers, each with their respective rack, and then one really fast fetcher.

A fetcher wouldn't have to have an arm at all but rather just be able to suck up tubes from the floor and drop them off for their hanger parters. The trick for such a strategy through is getting a chassis built as quickly as possible so your drivers can get used to the speed.

[pfreivald]

A cascade forklift is not difficult to design, nor is it difficult to build -- especially for a team with any kind of depth whatsoever.

This will allow you to reach the top row no problem.

Please, do your team a favor and don't settle. 3x2x2 is just so much better than 2x2x2... And it doesn't block your drivers' vision.

Don't just aim to compete. Aim to win. (Winning doesn't matter. Trying to win does!)

[mwtidd]

Originally Posted by pfreivald

A cascade forklift is not difficult to design, nor is it difficult to build -- especially for a team with any kind of depth whatsoever.

For my team, 319, the fork lift has actually been our nemesis. We have never done well in years where we utilized an extension mechanism. We do arms, and we do arms well. Oh and by the way, we're actually team 6 (we were a test team one year) I realize that a lot of teams dont do arms very well either, hence why I suggested having neither. We are among the oldest teams in first, but we find forklifts difficult to build.

Oh and by the way, our coach specifically wants an alliance partner who is a fetcher. As a good fetcher you will actually look very attractive to many teams come time to pick alliances.

Originally Posted by Chris is me

Scoring on the bottom and middle rows can be done with a single arm joint and no real expansion. Top row, nope.

Why can't a single jointed arm cap the top?

[Zoughtbaj]

The most important thing to keep in mind is the pros and cons of each level.

The higher row will yield the best points, but will prove to need a more complicated mechanism.

The middle row will yield decent points and will not need as complicated a mechanism, but will obscure your view of the field.

The bottom row has the least difficulty/physical consequences, but will score you the least points.


Just consider if the pros outweigh the cons, and judge on what you should do from there. For example, if a visual isn't needed because you have cameras mounted on your robot, then go for the middle if you like. Not to mention, there are various other strategies to attempt, as has been described already in this post.

[Chris is me]

Originally Posted by lineskier

Why can't a single jointed arm cap the top?

Sorry, cap the top and grab tubes from the floor.

[kyoung]

I would say go for the top row. This year is interesting in that the main game functions have been done and well documented. The gamepiece manipulators can be derived from 2007, and the lifting mechanisms from 2007/2008. There is a lot of value in looking at the successful robots from those years.

For lifting you generally have the choice between a multi-stage elevator or an arm. Both are rather simple mechanisms requiring 1 driven axel (usually 1-2 motors) and both can reach the top row without any excessive complications. There are pros and cons to both, but none are actually as significant as some would make them seem.

Remember, the inner tube has to be hanged, this does not mean that the lifting mechanism must reach the top rung. The bumpers must surround the entire frame perimeter. Your game piece manipulator must have some way of extending beyond the bumpers to pick up pieces (unlike 2007). If designed correctly, this mechanism can also get you the extra height boost to reach the top rung and if you're clever, you may not even have to power it.

Below are images of a quick sketch I drew earlier today illustrating an example of a basic robot design that can hang tubes on the top rungs of the scoring grid. (The gripper assembly could be powered by pneumatics or motors and the parallel bar linkage would be driven by motors with some sort of reduction.)
http://i.imgur.com/rDKI8.jpg (Dimensionless)
http://i.imgur.com/WjsFL.jpg (Dimensioned)