paper: HOW TO: Make Homemade Orbit Balls

[IKE]

Originally Posted by Bongle

Thanks so much for posting this. Now that we know that we can only guarantee getting 4 balls max, making suitable stand-ins is more important than ever.

Has anyone built any of these? How many man-hours do you find it takes to make a non-fabric ball? How much does the non-fabric portion cost? We're really looking to give our human players throwing practice.

I had five helpers and we made about 15 in 3 hours the other night. Three helpers then spent an additional 3 hours taping seems and cleaning up the edges.

For about $75 you can get a 4x8 sheet of 0.062 Polycarbonate. We then set up a jump shear 28 inches and sheared off 3 sections. We then set the jump shear for 1.125" and made about 110 strips. We used an 1/8" punch to put a hole in each end 1/2" in. We then followed the instructions from the instructable video. One thing I figured out too late is to make a wooden rivet pusher. Essentially a round slug that the pop-rivet stem can slide into (my fingers were very sore the next day). We then used special bonding agent after the straps were riveted. This acts as both anti-rotation and is also stronger than the aluminum pop-rivets. These balls seem nearly indestructible. We made 18 from 1 sheet and could have made at least 1 more.

All in all, 19 balls for $75 pollycarb, $5 glue, $5 pop rivet. You can buy a riveter at homedepot for about $12. If you don't have a punch, you can use a drill. All in all 19 balls for about $100.

These don't bounce quite like the real ones, but are accurate for size, weight, and feel. Most important they are more resilient so they are perfect for human player training. If you are planning on some sort of gather and dump system, they could work for the robot design, but I wouldn't trust them for a shooter.