Mini soldering iron battery powered

The main advantage of this mini soldering iron is that it is powered by a 3.7 V battery. It is not connected to the network and you can easily take it with you. Of course, its power is not great, but it is quite enough to solder wires or solder some fallen radio element.

So, what do you need to make a mini soldering iron?

Single-core wire with a core diameter of 2 mm.
A piece of a telescopic antenna.
Nichrome, wire 0.2 mm. 10 cm long.
Reinforced fiberglass cambric.
Rechargeable battery 3.7 V.
Battery compartment for this battery.
A piece of round wood.
Switch.
Thin single-core wire 0.3-06, diameter (multi-core can be unraveled).

Making a mini soldering iron

Let's take a thick single-core wire with a cross-section of 2 mm in diameter. We will remove the insulation using a clerical knife or another method.

Then we take a telescopic antenna from any receiver, joystick or walkie-talkie and disassemble it. We need to find a tube into which our core from the wire will fit tightly. Once the antenna elbow is selected, the remaining parts can be removed.

Using a machine or manually with a file, we sharpen a thick strand of wire into a cone - this will become a soldering tip.

Cut about 1.8 cm with a hacksaw.

We cut off about 4 cm of the tube that we took from the antenna.

We take nichrome wire and measure 10 centimeters, cut off the rest.

Let's take a wire with a diameter of 1.2-1.8 mm. It is only needed for winding the coil; we will not need it later. The material doesn't matter. We wind the nichrome wire, leaving the ends about 1 centimeter.

Then take a thin strand from a copper wire, fold it in half and twist it with wire cutters.

We will thread the nichrome wire into the resulting eye and twist the end around the copper wire. And let's put it aside for now.

Let's take the tube from the antenna and thread the reinforced fiberglass casing inside the tube. If your cambric turns out to be larger in diameter, you can make a longitudinal cut and adjust it to the diameter of the tube.

We take everything together and put it together.

We thread a nichrome coil with wire into the cambric so that only a 1 cm long wire sticks out from the outside. From this centimeter we make a turn around the thermal insulation. This will be a thermocouple.

We take our tip and insert it into the tube from the antenna.

On the other hand, we insert our thermoelement all the way.

Take a round piece of wood and cut off about 2-3 cm.

Drill a hole in the center for the soldering element.

We mill a groove from this hole using the same drill, see photo.

Insert the soldering tip with the thermoelement assembly. And bend the tail into the groove.

We drill more holes, but with a smaller diameter and a little further from the center.

We take a thin copper wire and make a loop on the tube and bend it. This will be the second contact.

We insert everything into a round piece of wood.

Fix the bent conductor with hot glue. And glue the battery compartment. Polarity doesn't matter.

On the other hand, we glue a switch to the battery compartment. We also fix the conductors with glue. We connect everything in series: thermocouple, switch, battery.