I was particularly happy with how this control for a separatory funnel turned out.

I was particularly happy with how this control for a separatory funnel turned out. The gears were made with involute gear plugin to Sketchup. The Small gear is stuck with friction, the large is held in place by the handle. The whole thing will be used in an automatic hand brew machine. I might add end stop for easy reset eventually.

Nice print, but wouldn’t a servo be better suited for this? The stepper has no idea whether the valve is open or closed.

A servo would work, but the whole system is controlled by Replicape, so the stepper controller is already present. Also, the valve is quite hard to turn, so it would require either gearing on the servo as well or a large/special servo.

I’m thinking of adding an end stop to indicate start position, though.