2013 - Ultimate Ascent

One of the mechanisms that separated Cathy form many other robots in the world was her collector. As one of the few robots at each of our regionals that opted to collect frisbees form the ground as opposed to the feeder stations at each end of the field, Cathy was one-of-a-kind.

Prototyping and designing a Frisbee collector at the beginning of build season, many ideas were given as possible collection-mechanisms; most comical was a plunger that was shown in the game animation. In the end after much prototyping using VEX wheels and plywood, we arrived at our roller-intake. The intake uses 3" Banebots wheels and polyurethane cord hooked up to Banebots motor and gearbox to grab frisbee and pull it onto our "scoop'". The scoop was mounted on wooden skis to help it traverse the bump on the field without catching seams in the carpet. With this, Cathy could pick up Frisbees form nearly anywhere on the field, as well as perfom an autonomous routine involving more than the three pre-laoded Frisbees each robot could start with.

Cathy’s hopper was built to be impossible to jam and as simple as possible. By lining up the frisbees side-by-side, one-by-one, we were able to avoid having any frisbee jams the entire season. The frisbees moved through the hopper by a polyurethane belt on the side of the hopper. During our test-and-tune process, we discovered that sometimes the belt would slip, and the frisbees wouldn’t move up the hopper. To prevent this, we used electrical tape to create "bumps" for the frisbee to be moved by on the belt. It worked very well, serving to prove that a complex problem can have a very simple solution. To index the frisbees, Cathy has two pneumatic cylinders mounted on the shooter tray. One is used as a gateway to block the frisbees from shooting early, and the other is used to shoot the final frisbee of the four on each cycle. Pneumatics were also used to move our tray up and down, as well as pull our robot onto the first bar of the pyramid at the end of the match for a quick ten points. To make sure Cathy has enough air, she has five Clippard air storage tanks, as well as an on-board compressor to keep compression throughout a match.

Cathy was our first robot to use a West Coast Drivetrain (WCD). A WCD is a drivetrain built for reliability and maintenance. The wheels are cantilevered on the outside of the frame to allow for easy removal and replacement. Our 4-CIM six-wheel drivetrain is built to be both reliable and efficient, being able to drive even if a drive chain were to break due to center wheels being powered directly from the gearbox.

The frame itself was welded together form 2x1" and 1x1" hollow aluminum tubing, and was slightly dropped center wheel to allow for a tighter turning radius, and the encoders mounted on the drivetrain allow for accurate movement in autonomous.