This project takes an existing tool — the Hakko FX-901 cordless soldering iron — and adds USB charging and a Lithium Ion battery inside a 3D-printed pack.
The FX-901 normally uses four AA cells, either alkaline or NiMH type. I like having this little iron around for cosplay electronics emergencies, and adding USB charging means there’s less to pack…it can use the same phone charger and USB cable I’m already traveling with. Less is good.
A fine little backup iron for anyone who does electronics outdoors…RC helicopters, ham radio, Burning Man, things like that.
No modifications are made to the iron itself or the original battery pack; it can still be used if needed. What we’re building here is a complete swap-out replacement for the pack.
Use the PowerBoost 500C Charger, not the 500 Basic. We need the former’s USB charging feature. And not the PowerBoost 1000C; it’s wider and won’t fit in the 3D-printed case.
- 3D printer. The battery holder is just under 110mm long and will fit in the build volume of most printers. For exceptionally small printers, try rotating the part 45 degrees, so it’s pointed corner-to-corner.
- Filament: transparent PLA or ABS is preferred, allowing the PowerBoost status LEDs to show through. White or natural may also work.
- Glue: 5-minute epoxy (preferred) or E6000 craft glue.
- Hakko FX-901 cordless soldering iron (and batteries, if currently using it to build this project). We don’t currently stock the FX-901, but it’s available through Amazon and elsewhere.
- Wire cutters, solder and related paraphernalia, optionally some heat-shrink tubing
- 2 (two) #4-40 x 3/8" oval- or pan-head machine screws (steel, brass or zinc-plate, not nylon — we’re using these as makeshift power terminals)
- 4 (four) #4-40 nuts
- 20 gauge wire (for powering the iron)
- 30 or 28 gauge wire (for the on/off switch)
- USB power adapter and A-to-microB cable for recharging