Hot air soldering gun

I decided to build a hot air soldering gun after all attempts to build a kind-of-working roflow oven.


  • Simple construction (?!)
  • Easy handling
  • Better for the purpose I want to use it for

I saw an inspiring post on Hack a day here; which made me creative. The whole thing should be cheaper than an Ayoue (?) hot air soldering station (~85€).

And that’s what came about:

  • 400W ATX-Power supply with 18A on the 12V-rail(ebay 10€)
  • DIY controller with 4 PWM channels (Atmega644 @ 20MHz, 4 Ch PWM Controller with ~20A per channel, 2 * MAX6675)
  • DIY heating Element (up to 500°C [!!])
  • Aquarium air pump bis 4l/min (Aquaristics-Shop (ouch) 25€)
  • PID-controlled temperature (ca. +- 1°C)
  • -> Expandable via I²C

Action-videos will follow soon!


  • I work on a new heating element – completely made of glass this time…

Source & Layout:

Now; see for yourself!

Max6675 debugging at its best…

Programming & Debugging united…

The controller was mounted on the power supply and wired up…

The heating element. It consists of ~10cm resistive wire (~ 1 Ohm) inside a
standard glass tube. Simple but efficient!

Front of the heating element (output), right: Thermocouple; yellow is the
silicone-insulation of the -end of the resistive wire. The silocone-tubing, which transports
the hot air to the output nozzle is lacerated; this is still a problem (silicone doesn’t work with 500°C !)

Further detail of the heating element, the GFK-holder is burned, it is already replaced by an
aluminium one.

This is how 500°C looks like on GFK…

The heating element with cable harness

Whithout words (for DIY-cred… 😉 )

The heating element in its case, and the airpump. MSP430 Launchpad to scale.

Output nozzle; still with GFK-spacers

The controller inside a nice casing and CNC-milled front (and back) plate.
The two DIN-connectors on the right are extension connectors.

With a connected hot air gun… (air is supported seperately)

Sure, the case is retro, but hey!

Backside, also with milled plate.

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