This is the product of our first week of brainstorming, prototyping, and design.
Our strategy:
-Score pieces quickly. Quick ground to peg time.
-Be maneuverable. This speeds up piece retrieval and helps us place them accurately (particular by strafing).
-Make it simple and reliable. We hope to attend 2 or 3 events this year as opposed to previous years' 1, so we want it to last.
-We also hope to have more of it CADed before construction so it can come together more cleanly and much, much more quickly, leaving lots of time for code, testing, and practice.
Our solution:
We determined that strafing was very near a requirement for placing the pieces because tank turning would be very limiting and almost always slower even with practice. We therefore arrived at the holonomic drivetrain that we
prototyped; the competition robot will use four 4" dualies. It favors the forward direction (2 CIMs per side) for faster field traversal, but still strafes (with 1 or 2 RS 775s per wheel) and turns very well over short distances. The frame is an octagon to increase stability (?) and keep turning effortless. It will be welded aluminum box tube, 1" by 1/8" wall.
For a lift mechanism we have decided on an elevator very similar to that of Team 25 from 2007. We got the idea from the 2007 Behind the Design book, and watching match videos confirmed that it worked well. We determined that we needed to pick up off of the ground, because we think most of the pieces will be there at some point, and we don't want to be limited to the slot. The elevator can reach the top peg with just 2 stages and a gripper that rotates the game piece from pickup position (horizontal) to scoring position (vertical). It will be powered by an FP and should be able to lift at 12 ft/s (!), not counting inefficiencies, friction, etc. The gripper is not yet finalized, but will likely be a simple pneumatic clamp.
All the electronics, battery, and motors will fit within the 12" tall octagon (not shown). The minibot will conveniently sit on top behind the elevator, at the appropriate deployment height. Design work to be done includes the gripper and the minibot and minor details for the elevator and the drivetrain.
We haven't decided on a name yet. Suggestions welcome!