servo powered pinch valve

thingiverse

made this valve a year ago, finally find time to upload it to this site. the function of the valve(s): there are 3 valves in the unit: 2 for liquid, one for air. the 2 liquid valves are side by side and the air valve situated on the opposite side and between the 2 liquid valves. when the servo arm moves to one side, liquid valve 1 is open, when it moves to the other side to open liquid valve 2, the opposite side of the servo arm will open the air valve before valve 2 is opened. my usage for the valves: (one sweep of the servo) hot liquid in --> hot liquid stop--> air in to flush out hot liquid --> air stop --> cold liquid in. the position and time of the servo is controlled by an arduino. the liquids provides temperature changes to lengths of SMA running in parallel which has a much higher force/weight ratio than what biological muscle has. the weight here includes all of the hardware, heat source, liquids, pump, battery, etc. and its very quiet. can be silent when servo is replaced with SMA actuator or steppers. the tube is made of soft molding silicone, made the mold in wood (2 halves), then pour molding silicone into them, cure, glue together with silicon. Instructions use super glue or acetone to attache the axle cover