[MOC] Huge NXT Ball Machine

[Purple Geek]

This LEGO ball machine was constructed using 10 motors and thousands of bricks. Its 14 balls move continually through the machine, taking approximately two minutes to complete a lap.

Two Mindstorms NXT bricks control the green lift, blue lift and ball counter. A combination of Power Functions and traditional 9V motors drive the remaining lifts. The machine is built entirely from LEGO -- even the balls are LEGO parts.

Width: 63.5 inches

Depth: 24 inches

Height: 30 inches

A video showing the machine in action is available on YouTube:

Let me know what you think!

Ben

[Doc_Brown]

This is huge! Fantastic job!

I love the colour coordination.

Something strange about your video tho, its like its stop motion.

[TinkerBrick]

Really cool GBC. But the video should have a higher frame rate. It kind of makes my eyes hurt.

[Purple Geek]

Thanks for the feedback about the frame rate. I didn't realize it was a problem until you commented on it. Unfortunately it looks like the webcam that I used was only recording 10 frames a second, which is why things are jumpy :(

[Junpei]

It does kind of make my eyes hurt, although how it looks like stop-motion is kind of cool. Great job on the machine, I have no idea how you did the counter. Did you use NXT motors or is it mechanical?

[Purple Geek]

The counter is actually pretty simple -- there is an ultrasonic sensor that detects when a ball rolls by. Each digit in the counter is connected to its own NXT motor. When the ball is detected, the correct angle is computed for each digit, and the motor is advanced the correct amount. The digit wheels are brick-built circles that have ten 4x7 stud plates wrapped around them that are connected together with clips. The number itself and some plates on the back hold together a 4x6 plate and a 1x4 plate to make the 4x7 plate. A mechanical counter would be really nice, but that's beyond my skill level at this point.

Ben