Here is the current version of our working prototype.

With a ball

the metalic ball, as previously mentionned has not enough contact surface with the lines to be fully detected. We have to find another material, or texture, or field design to make it work properly.

With a cylinder

But then with a metalic cylinder, like this endmill, it works great. Even if the stepper motor is currently to slow to be reactive enough to follow quick movements.

Should we change the name of this pong machine to something else? We feel that we have created another game, a collaborative game :)

Which step have we reached?

We have found a low-tech way to detect the position of a ball and move a motor accordingly. Of course, we didn't get the end result we wanted, a fully functional pong machine, but we managed to create the basic tools to make it work. And we are super happy with it.

What is to be done?

First the metal ball we are using is only detected once out of 5. We think that is due to the fact that the ball is a sphere, and therefore has a very small contact to close the circuits between the two lines - theoretically just a point.

There are different solutions for that. Either we bring the lines of copper even closer (we have tested with laying out copper tape and simply cutting it in half in length with a cutter, therefore just creating a gap between both), or on the contrary bringing them a tiny bit further apart so that the ball can sit in the ridge created between them and allowing for two contact points. It might make the ball bounce a bit, or even getting stuck, so we’ll have to see.

Secondly the motor doesn’t move very fast and the ball can easily cross to columns without the motor catching up. A solution would be to move the motor off the rail, therefore having less weight to move around. It might not be good enough and we might just need a faster motor. To study more.

Thirdly, we haven’t actually gotten the solenoid to work. It might hit the ball to hard, it might miss it - hit too early or too late.

Extra ideas

• Have lines in the length of the board to calculate speed
• Only have one "player" and the other side the ball just bounces against the wall
• That wall could be slid closer or further away from the rail to change the level of hardness