Water level sensor

thingiverse

This simple sensor, printable for water level monitoring, requires three metal washers (1/4" inner diameter) and wire. Print float-allparts.stl or assemble three washer holders along with other parts, excluding float-assembly.stl, which is only for visual guidance. Assemble the components according to the photo or float-assembly.stl illustrations. Make a hole in your container's lid and connect the center and bottom pieces around it. Cut 3mm filament to set the water level threshold; when that level drops, the float moves the top washer onto the other two, completing the circuit. Hook positive to the top washer and negative/ground to both lower washers for stable operation across varying conditions. A secondary sensor can act as a control or upper threshold in conjunction with a flow control valve like http://www.thingiverse.com/thing:8394.