A valve for liquids, driven by a servo motor. This way you could automate a flow of liquid.
The usefulness of this design depends on the type of valve you have, or can get your hands on. This 'thing' is therefore ment to share the idea.
I have chosen to separate the frame in 3 pieces. Two where necessary to insert the valve, and the third is necessary to hold the servo in place. The parts can be printed without overhang.
Because the valve needs to turn 90Âº to completely open or close, and this particular servo (http://www.dfrobot.com/index.php?route=product/product&filter_name=servo&product_id=120) can rotate 140Âº I have chosen for a gear ration of 9:14. This way the servo maintains maximum power while opening or closing the valve.
Notice that I did not use any nuts on the bolts to keep the parts in place. I printed the holes and tapped some screw thread in the holes (M5x0.8). Be gentle while doing this. Because of the friction causing heat, the holes can start deforming while doing it. So do it slowly.
I did not put in any holes in in the servo holder design to keep the servo in place. I have used a 2.5 drill to make the holes and 2.5M bolts and nuts to put the servo in place.