DIY Fume Extractor With ATtiny13 Speed Control

Let’s be honest, commercially-available soldering fume extractors are cheap enough that you probably don’t need to build one yourself. But it still makes for a good starter project, especially if you go out of your way to really flex your maker muscles like [Arnov Sharma] did with this tidy build.

All the hallmarks of modern hardware making are on display here — you’ve got the 3D printed enclosure, a motor salvaged from a cheap toy quadcopter, and a custom PCB which uses the ATtiny13 and an AO4406 MOSFET to implement a PWM speed control.

The first press of the button starts the motor off at max speed, but keep pushing it, and the motor’s speed will ramp down until it turns off entirely. There’s even a TP4056 charge controller to top off the internal 18650 cell when the fume extractor is connected to a USB power source.

Is it over-engineered? Perhaps. But projects like these are a great opportunity to practice your skills, whether it’s PCB design or creating bespoke 3D printed enclosures. In the era of cheap 32-bit microcontrollers, it’s also refreshing to see hackers still dragging the ATtiny from time to time.

Thanks to [Abe] for the tip.

15 thoughts on “DIY Fume Extractor With ATtiny13 Speed Control

  1. Crazy noise from the prop.

    Just get a 5V PC fan, glue it to some small baseboard to keep it upright and plug into USB power supply. Low noise and gets the job done. You probably want always the maximum sucking power anyways..

    1. This does not seem to have any filter material anyway. For just blowing the fumes out of your face, most fans have much more directed flow on the outlet side. I have a small PC blower fan mounted 50 cm away from where I solder, blowing sideways over the table.

      1. Instructions show the chamber on the back is supposed to be packed with cotton, though it looks like for some of the demo shots it’s not in there.

        Could debate how well it works (see comments below), but at least it’s something.

        1. Occasionally that is true. But not always. Besides, asking here is going to get a bunch of opinions. Asking the author is going to get a bunch of reasons for the choices that were made. Plus, people need to be reminded that there is often no connection between Hackaday and the projects it presents.

          1. That assumes they are experts. Either way, it makes sense to ask the project author AND to get other opinions. A good source for useful (expert) info are filter makers like 3M, who will tell you what filter is useful for face masks to filtering solder fumes.

    1. At work, I built a fume filter from 2 12v server fans mounted next to each other on a piece of wood, with a ‘bag’ i made from a carbon filter from a cooking stove hood. The fans are next to each other, almost at table level. This works VERY well to suck away the fumes running on 5v. The air flow seems to stick to the table. If i’m working with solder paste to join small sections of pipe together, i can crank up the fan speed (at the cost of a lot of noise) to suck away the rather large amount of oily vapor that produces.

      I cannot scientifically judge how effective it is, but i can tell two things: the smell while soldering is dramatically less, no visible smoke makes it out of the filter, and there is a lot visually extremely fine dust stuck to the inside of the filter after a year of soldering several hours a week.
      With an air compressor i blew out a cloud of very fine, almost white rosin dust.

      The cheap conrad fume extractor i have for personal use has a more coarse open cell foam carbon filter in it. It does not nearly work as well – if i hold a smoking soldering iron right in front of it, i can see the smoke being shot out of the back. I resorted to putting some conventional (no carbon) cooker hood filter in front of it, which works a bit better.
      The Conrad fume extractor needs to be very close (<20cm) over the board you're working on to suck up any of the smoke. In my experience that's unworkable. I tend to put it at 5-10cm distance on the table, instead of mounted onto its arm hanging above the workpiece.

      How effective the cotton is, i can't tell. But it will certainly already make some difference. If you're really worried, you could get an aliexpress particulate meter and see how much particulate matter is floating in the air in your workspace during soldering with the various kinds of filter available. They're not too expensive, less than 100 euro.

  2. Don’t underestimate the impact of the fan protector (fan-grill). Even a standard stock-fan-grill made of thin steel-wire reduce the airflow more than you would expect….no comment needed on this design :-P
    And this project should also place the fan in a cylinder to prevent air going to the “sides” instead of going out. I expect this design to create a lot of air turbulence inside the cabinet resulting in even less air flow.

    1. I don’t think the question was ever whether fume extractors are particularly efficient or protect your lungs 100%, but rather given the same setup would you be better off with or without an extractor. Of course there should also be a third setup to compare against: a simple fan and a nearby open window! But the third option isn’t always possible so if a fume extractor even provides a little benefit over just directly breathing in the fumes then I’d consider it beneficial to make and use one.

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