Over-powered Fume Hood is Awesome

fume hood

Recognize the Black & Decker unit up top? Yeah, that’s part of a leaf blower.

[Paul] does a lot of soldering. He had one of those cheap desktop fume extractors but it just wasn’t doing the trick. So after being inspired by the countless DIY fume hoods, like this one, he decided to try his hand at it. A sale on an electric leaf blower inspired a Saturday afternoon of hacking.

The leaf blower is one of those models that can also suck up leaves, so no modification was necessary. He still cracked it open though and upon taking it apart he discovered the motor is in fact a Universal Motor, that can run off of AC or DC! Not wanting to suck up his entire setup, he began to play with a variable power supply to determine the best voltage to run it at — 30V was the sweet spot. Quiet, but still powerful. A few simple modifications to the case and wiring, and it was good to go.

Next up was the enclosure, and like most fume hoods, he started with a large plastic bin. He also happened to have some nice aluminum profiles on the scrap heap that he used to finish the cut edges of the bin, and to support the leaf blower with. It’s done for now, but he also plans on cleaning up the wiring a bit more permanently and adding a proper carbon filter. You can still tell it’s a plastic bin, but we have to admit, it looks pretty nice!

16 thoughts on “Over-powered Fume Hood is Awesome

  1. I used a bathroom ventilator fan for mine.
    Built the enclosure from 2×2 stock and some thin translucent
    plastic sheeting that was left over from another project.
    I’m always afraid I will get distracted and leave the bench with the
    hot air rework or iron left on so I wired up a foot switch…

  2. A motor speed controller would have worked just as well. Many people control universal motors with light dimmers. It shouldn’t work, but it usually does. Once again Had celebrates the overly complex over the more obvious solutions.

    1. >Had (sic) celebrates the overly complex over the more obvious solutions.

      Uh what? The guy had a 30V supply lying around. Using that instead of a variable AC supply or a motor controller is definitely the simpler solution.

      1. sic this HaD doesn’t allow editing of comments. I could think of better things to do with that toroidal transformer too. Fucking thing must be worth more than the damned blower.

  3. I hope he doesn’t leave it un-attended…with a bit of flame the whole rig could turn into a perfect blast furnace with all that wood around it. Note to self: get fire extinguisher at Costco.

      1. Dead motor is your biggest worry. Wire it up so the oven is off if there is no air flowing (how you monitor that can be anything from measuring motor current to wind sensors).

        Add a thermal cutout to the oven case so it switches off if things get too hot. It may already have one inside.

        1. A simple way to do that would be to simply put the exhaust motor and the oven on a common power strip, and power both on and off with the strip. Easy peasy.

          1. And how would that cut the power if the motor died? Good news: you’ve involved a power strip, bad news: nothing different will happen. Might as well throw an Arduino on it…

  4. so… cheap easy use, take that little battery powered dust vacuum no one ever uses, the one that came with your (ryobi) drill, zip tie the trigger, duct tape your dryer duct, you could have a portable low quality fume hood.. cheap as hell… not great, but small enough to take on a bicycle with your mobile workshop.

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