Mathematical marble machine


Here’s something I always wanted to make, and a big reason I got a GF in the first place (since then, I’ve found hundreds more things I can make!)

It’s a machine that rolls balls in different tracks and changes tracks each time. The pattern is called an ABACABA pattern and it’s the same structure as in binary numbers. (Perhaps you can see how the machine is counting from 0 to 127 in binary?)

The balls fall on a xylophone, 8 notes from an A to another A one octave up. It literally plays “ABACABA” (which continues “abacabaDabacabaEabacabaDabacabaF…”)

The lifter took the most work. I’ve made a nice battery pack since I took that video. The motor is a worm-gear high-torque motor that turns 15 rpm runs on 3v. Each gear has 16 slots, so it delivers 16 balls in 4 seconds, or one note every 1/4 second. More or less.


Really cool machine! I can watch it count by reading the positions of the gates.


Excellent job. I love it.


Fun to watch!


Amazing to see a Glowforge involved in the genesis of this. Someone makes something like this and, when they show it, you just stop and stare.

Fun project! Thanks for sharing.


Had me in a trance


This is so cool!! great work!


That is great! Love the lift :sunglasses:
How satisfying to see your efforts manifest.


This is super. I love marble machines. Somewhat of a Sisyphean element. It is a great attention holder.




That’s amazing. What a great finished project.


Wow, that’s really well done. Reminds me of the Digi-Comp II marble calculator kits from the '60s - except much more elegantly realized, and with musical elements to boot. Really impressive.


It’s mesmerizing! Really fun to watch—thanks for sharing!


Modern digi-comp II replicas can still be found online. Look through the following topic:


Very interesting. Marble logic is mesmerizing to watch.

I still have an old Digi-Comp I mechanical computer (3 bits, 3 flip-flops, no marbles) that I bought in the mid-60s after saving my allowance. Many years later, I saved my allowance and bought a Glowforge. 8^)

Come to think of it, I could use the Glowforge to replicate almost all of the parts for the Digi-Comp I. I’ll put that on my list of projects to try.


Now this is a fun project!


I think I see some Wintergaran influance there. Am I mistaken? If so you really nees to see the Marble Machine X!


Love it. Great job.

I’m a big fan of this guy.