• Catch the ball which appears at a randomly distributed position and time
• Throw the ball with as much precision as possible
• Adjustable to control throw trajectory
• Robust enough to remain fixed in while constantly being bombarded with impacts from balls

This image shows five iterations of design.

1/2" plywood for the back and base

3" drain pipe (white) - for catching part

1.5" PVC pipe (black) - for throwing part

0.75" PVC pipe (white) - spacer between bases

1/4"-20 threaded rod

nut and washer

wingnut

3/8 aluminum tube (not shown in this image)

The throw trajectory can be adjusted to be more upward or more outward by changing the angle of the hand. The hands pivot on a 3/8 diameter aluminum tube (anodized black - this comes from an arrow shaft). They are held in place a 3" piece of 1/4"-20 threaded rod. A nut and washer go on one side of the threaded rod, and a plastic wingnut goes on the other side.

The center part of the threaded rod is not used, so I turned that down on a lathe to reduce weight.