Wanted to make my own version of a marble adder without moving parts. Tried to design it so I could stack the adders on top of each other. I am using 9.5mm balls for this.

The towers act as the digits in a binary number, the highest tower being 1, the next 2, 4 , 8... each ball you insert to the top of the tower is like performing a +1 operation.

No supports!