How to Make a Makita Battery Soldering Iron (with Worklight ?)

Hi,

This is probably for people who already have a Makita LXT battery and tools and want to add a soldering iron to their battery powered tool line up.

You will need to buy major items

1. Makita DML186 LED Torch (approx. GB£13 / US$17 current prices 2021)

2. Total Tools P20S / TSILI2001 battery soldering iron (approx. £20 / $27)

The DML186 is really just a nice, convenient and relatively cheap way to attach the P20S to the LXT battery.

Tools and supplies I used are

Soldering iron and solder

Cross head screwdriver

18-20AWG wire - 2 colours if possible, about 6-8" or 150-200mm

Drill or Dremel tool

3mm drill bit (use in Drill / Dremel)

Dremel side cutting bit (or a needle file or 2)

Small (3mm) cable tie

Leatherman or wirecutters

Penknife (edge clean up as needed)

Solder and wire as noted.

Remove the screws from the P20S battery/DC adapter.

Remove screws from Makita Torch.

Separate the P20S sides and remove the P20S DC adapter assembly.

Expose the insides of the Makita torch.

De-solder soldering iron cable connections

De-solder DC connector pieces from driver board and separate from plastic mounting piece

Put the DC driver board into the Makita case in position between LED board and Yellow Battery connector board.

Mark up where the switch will be

Drill 3mm hole and enlarge to switch hole shape using a needle file or Dremel side cutting bit.

Hole will look something like this (or neater) - needs some work to remove position marks !

A cable tie holds the DC driver board in place ...

Drill a 3mm hole in DC driver board and a corresponding hole in the Makita LED board

Avoid cutting small traces near edge of DC driver board. There is free space to drill into.

Pass cable tie through LED board ready

See photo ...

Solder new wires to connect Makita DC board and DC driver board - approx 3-4" (75-100mm) long in Red and Black in my case. I used AWG 18 (0.8mm2) wire but AWG 20 (0.5mm2) should be enough for the approx 2A draw.

Re-solder the soldering iron's DC cable to the DC driver board in the new orientation, preserving original polarity (twin cable has ridges on -Ve wire)

Cable tie the 2 boards together in position through the 2x 3mm holes as in photo.
Cut off excess cable tie length.

Cut a slot in the 2 sides of the Makita LED case.

Exit hole is offset to the new switch hole side, only a semi circle is cut in the other case part.

This offset is in order to avoid fouling the capacitors on the DC driver board.

Assemble and test.

Green glow of soldering iron telltale LED shows through the new soldering iron On/Off switch hole.

LED torch still works (a work light ! )