I've never gotten one to make what I am thinking of: A Galton board. At the top, several inches apart are two holes from which balls drop. One drops blue balls, the other red balls. They form a merged distribution below in columns, demonstrating dual overlapping normal distributions

Imagine one of these: https://imgur.com/a/DiAOTzJ but with two spouts at the top dropping different colored balls

Its attempts: https://imgur.com/undefined https://imgur.com/a/uecXDzI