3D printed solenoid demonstration

*** Note: the idea of this demonstration is to show the basic principles rather than to create a high efficency powerful solenoid ***

There are two pieces that print out: i) the main part forms a bobbin to wind the wire around and to take a 6mm diameter shaft, and ii) a smaller part that slides onto the shaft (and is fixed in place using a small self tap screw) that acts as a stop to limit the amount of movement the solenoid can make.

I used a small wooden dowl (ca. 6mm diameter about 80 mm long) for the shaft but a plastic or perspex rod could be used instead.

The coil resistance (I used ca. 100 - 200 turns of ca. 1mm enamelled copper wire) is quite low (a few ohms) and so this demonstration solenoid only needs ca. 1.5 or 3V from one or two D sized batteries (a 6V lantern battery will also work well).

Pulse the battery, by reversing the battery connections ON-OFF, to move the magnet on the solenoid. Dont leave the solenoid permanently connected, as it will drain the battery quickly.