when you spend an hour trying to get something to work and all you needed was one block
I needed a rotational speed controller, if you were wondering
It's like that meme where it's the guy saying he just needs that one piece, and the piece is labeled "a billion dollars"
For getting higher rotational speed you can also chain large and small cogwheels alternately. A big one on the input shaft connected to a small one, the small one via shaft to another big one connected to a small one and so forth.
I know, but I needed it to be compact, which is why I didn't want to go for that.