Tools and materials

You will need the following materials:

  • Kit of parts from my Tindie store, version 4.

  • Two 18650 Li-Ion batteries. Look for high-capacity (at least 3000mAh), unprotected batteries from a reputable manufacturer such as Panasonic, Samsung, or Sanyo. Do not try to save money by buying no-name battery on eBay or Amazon; instead, use a specialized store such as 18650batterystore.com. Batteries must be identical, ideally from the same batch. Current rating (5A/10A/20A) doesn’t matter much for this project. I used these batteries.

  • Polycarbonate tube, 11F (55in/141cm), 1 inch outer diameter, from flowtoys.com. Note: while the tube is listed as 55”, the actual length is 54.5”.

  • 1/2 inch (or 12 mm) square wood dowel, from HomeDepot or any other hardware store. You need two pieces, each at least 52 cm (slightly over 20”).

Tools

You will need the usual tools and supplies:

  • wire strippers

  • pliers

  • flush cutters

  • scissors

  • decent soldering iron, solder, and flux

  • heat gun

  • hack saw

  • electric tape, black, 3/4”

  • fast-setting epoxy (I use JB Weld Clearweld 5 minute epoxy)

  • black spray paint

You will also need a computer with WiFi to upload the images and a charger (either 5v charger with 5.5mm/2.1mm barrel jack connector, or a USB charger and USB C cable) to charge the batteries.