Milwaukee M18 Compatible Flashlight with USB Charger

This handy flash light takes M18 batteries and uses off the shelf electronics. Additionally it has USB ports for the convenient charging of your electronics. 

Note: This is still a fairly rough design. The project is fully functional, but the design has not been fully optimized for printing or assembly. Soldering is required, so and as with any electronics project that involves lithium ion batteries, there is a risk of burning down your house if you mess things up too badly.

Bill of Materials

• 20awg or 22awg wire

• 3x 16mm M3 cap head screws

• 2x 25mm M3 cap head screws

• 2x 100mm M5 threaded rod

• 2x M5 nut

• 2x 4.8mm female spade connector

• 2x 6.3mm female spade connector

• 2x 6.3mm male spade connector

• 1x SPST 15mm round switch

• 1x 28mm round USB charger

• 1x Off road light pod

• Misc mounting hardware (included with off road light)

• 1x low power cut off board

• 100mm length of 3/4" wide by 1/8" thick (19mmx3.5mm) aluminum bar

• CA glue

• Silicone sealant (optional for waterproofing)

Printing Notes

For my initial version I used PETG as it prints fast and easily (and I have quite a bit of it lying around). If this proves inadequate I will reprint in PA6-GF. 

Most of the main parts require supports. Printing orientations should be pretty self explanatory. The 3D models are oriented how they are in the actual model, you will need to re-orient them in your slicer. I printed the main base on its base using conventional supports on the bottom. The upper part of the base does need need any support. The cover gets printed on its side (the large flat side opposite the hole for the USB charger). I used tree supports for it. The handle pieces get printed on their flat ends, also with conventional supports.

Printing the bar cut guide is optional, it is only used to layout the holes and size of the aluminum bar that holds the handle. The holes in the guide obviously correspond to mounting holes in the base and handle. The small lines on the guide show were to cut.

Assembly and Wiring

Assembly is a bit finicky but pretty straight forward. The wiring as electrical components are all installed in the base, then other parts can be added.

I have included an example wiring diagram. The connections to the low voltage cutoff board obviously need to be soldered. The others can all be crimped into the spade connectors. Keep the wires as short as possible; there isn't a ton of room inside the enclosure and they take up a surprising amount of space.

Feel free to reach out with any questions. I will update if/when I refine the model.