Flashlight with Conductive PLA - No Wires - Fully Printed

I was attempting to design a simple flashlight using conductive filament with the goal of being entirely printed (just add batteries and bulb) with a single extruder 3d printer. After several iterations with limited success (see here) I finally arrived on a successful model. 

Unlike earlier iterations which used a color change in Prusa Slicer as a way to print “wires” into the model, this version uses a small conductive cap on top of the battery and a screw in holder for the bulb or led which also doubles as the switch. The change to the 9v as well as the shorter distance the current was traveling, both increased voltage and reduced the resistance from previous models. This allowed for a much brighter led and what I would call a successful flashlight.

For this print I use the Protopasta Conductive Filament for the conductive pieces, and any flavor of regular PLA for the non-conductive. It can be done in just two prints, obviously the two conductive pieces on one print and the two non-conductive on the other. The conductive filament has very good bed adhesion, so if you feel like you are well calibrated a brim is not necessary on the conductive parts. The conductive parts should be printed at 100% infill, I have done non-conductive at 5% and 15% in testing with no issues so adjust to your liking.

A standard 9 volt battery is used along with a 5-24v led flashlight replacement bulb. The bulb is squeezed into the flashlight bulb conductor with the led toward the non-threaded end. It can be a bit squirrelly to squeeze in but once it does it stays locked in nicely. The flashlight conductor is inserted with the terminal lug against the negative terminal of the battery, then the screw cap is installed and seats the flashlight conductor against the battery holding them both in place. At this point the threaded hole in the flashlight conductor should be above the positive terminal of the battery, simply thread in the flashlight bulb conductor and once the end of the led makes contact with the positive battery terminal the light should turn on, unscrew slightly to turn off, and voila a fully printed flashlight. Be sure to test fit all pieces without the battery or bulb before assembly.

If you want a clean look, or want to reduce conductive filament use, a color change can still be used on the conductive parts to combine conductive and non-conductive into the same print. When printing the conductive parts, start with the non-conductive filament and insert a color change in the slicer at layer 15 (make sure to check that is the right layer) and it will make it so the flat side of the flashlight conductor and the tip of the non threaded end of the flashlight bulb conductor are non-conductive and in the color of your choosing. It saves around 2.5 grams of conductive filament use.

A note on switching filament, the conductive PLA is DARK, and takes a lot of purging/printing to fully clear. Switching to the conductive during a print as described above is not a problem, but when switching back to normal PLA afterwards I often just print something small as a way to fully purge the color. 

Diffusers to use with the optional Bulb Diffuser Conductor are available here.

If you have any questions let me know.