Cyclone Dust Collector Requires No Bags Or Filters

After discovering their dust collection vacuum was blowing through filters and leaking powdered fiberglass dust all over their workshop, the folks at i3Detroit decided to take matters into their own hands, and built this awesome cyclone dust collector that requires no bags or filters!

They were inspired by a similar wooden sawdust collector, but as they cut many different materials, they decided to build a steel cyclone for durability. The build makes use of two 5-gallon buckets, a 5-gallon vacuum cleaner, and a meticulously designed sheet metal cyclone cone. The vacuum creates a strong suction force and the dust enters the cyclone, getting sucked to the bottom and into the blue bucket. This keeps the filter in the vacuum clean, and keeps all the debris in an easy to access bucket.

To build the cone they used galvanized sheet metal, and cut it to shape with a pneumatic nibbler. A sheet metal roller helped form the cone, which was then riveted together. To seal in the cracks they used duct sealer and foil tape. After adding some vacuum hose and accessories the build was done — approximate cost (minus the shop vac) was around $50, making it a very affordable and quick to pay off project considering the cost savings of replacement bags and filters.

To see another example of cyclone styled dust collectors, check out this one which can also be made using stuff you probably have lying around the shop anyway!

[Thanks Evan!]

46 thoughts on “Cyclone Dust Collector Requires No Bags Or Filters

  1. I made one a few years ago, using a shop vac, I used it with my CNC router and to clean the floor in my work shop, I found you do still need a filter because any light and fluffy stuff or fine powder will still make to past the cyclone dust collector, I hated cleaning the clogged shop vac filter every other month, so what I did was to cut the paper from the shop vac filter and replace the filter paper with aluminum window screen, then have the shop vac exhaust vented outside.

    1. Hello just need know how long a vaccum cleaner run countinous hours.

      I want to make a dust collector with 1800 watts vaccum cleaner hitachi and fixed on a cnc router for countinous use along the cnc router job.

  2. Lots of info on that Bill Pentz site. I found it when looking around for fan shapes while in search of more
    flow from a backpack blower.
    I was wondering about radiusing the leading edges
    of the blades and also about feathering the tips.
    That abrupt square step in the blades after the
    initial little sweep
    sort of makes me wonder about turbulence
    AND noise.
    Also looked at the dead spots (cavitation) along the blades where the dust/dirt tends to settle out
    and leave “shadows”
    Wondering how much loss it’s creating and also extra vibration and noise.
    Even if I couldn’t gain any real performance
    I would be glade to reduce any noise
    IF it could be done without losing output.
    Both volume AND velocity are important in this application.
    I’ve played with pipe diam, length and nozzle shapes
    you may trade one for the other but bottom line is..
    Velocity is what loosens the leaf litter and then volume
    is what carries the material away.

    1. Sorry about that folks. It wraps when I write and looks like it does when I post.
      But I have font size and type overridden in FireFox
      (the monocular diplopia thing )
      so I guess I’m just overlooking the “Shatner-izer”
      setting somewhere :^)
      or else I’d try to disable it.

  3. Oh and yes, You still need a filter after the cyclone.
    You need to think of this as a multi stage.
    The fan in your vac will get clogged
    also the dust buildup can tend to throw the balance off
    and severely shorten the motor life.
    Plus the air from the dirt stream generally provides the cooling for you motor
    so any fines will reduce life.
    Eats brushes and commutators and desiccates impregnated bushings and contaminates ball
    bearing lubes..not good either!

    1. You’re right, there is a filter after the cyclone. It’s the nicest HEPA filter they make for this particular type of vacuum, and thus it’s quite an expensive filter! But we’re trusting our lungs to it, so that’s okay.

      I believe that filter is actually the single most expensive part of the system — more so than the vacuum motor itself, more than the cyclone parts, more than the sealant and hoses and bucket and everything else.

  4. I’m compelled to point out that dust in cyclone separators doesn’t get “sucked to the bottom”. The aerodynamic forces on the dust particles are always trying to push the particles along with the air flow up and out of the separator. It’s inertia and gravity that pull the dust downward into the bin: The spinning motion tends to throw the dust out toward the walls, and the dust particles can’t quite keep up with the tight curvature of the airflow, so they drift outward a little toward the wall, where the airflow is slow enough that it pulls even weaker, so the dust inexorably floats toward the walls of the separator. Once the dust is in the boundary layer at the wall, the aerodynamic forces are dominated by gravity and the dust falls to the bin.
    Careful design work is involved, because the centripetal force on the dust must always be lower than that needed to make it spiral in with the air, and these conditions aren’t guaranteed.

      1. They’re essentially the same in operation: A cyclonic region throws dust out to the outer perimeter of the chamber to fall down into a collection bin and then some device prevents the air flow from picking up the dust again. The long cone shape in a “standard” cyclone separator serves the same purpose as the baffle in the Thien filter.

  5. I can usually fill my 5 gallon bucket 3 or 4 times before I need to clean out the vac’s filter. The really light stuff still makes it through. Also, long stringy stuff will almost always make it through. Had to pull my vac apart once because I ran it without a filter and sucked up some backup tape chunks from a “destructive tape wiping” session.

  6. The one thing I don’t see mentioned Is static electricity. My dad and I built something like this a couple of decades ago and the static buildup was enormous….had to carefully ground everything, run conductors through the hoses etc.

    1. Interesting! It hasn’t been an issue, but we’ll definitely keep that in mind.

      Perhaps because both the vac and the mill share a grounded outlet? There’s nothing electrical in the cyclone, so it doesn’t much matter, and the material isn’t flammable so I see no cause for concern on that front.

      1. Grounded outlets are good, but this is static electricity which is a different beast – the plastic hoses and dust/airflow will build up a charge big enough to put you on your behind if not directly grounded – you’ve essentially built a self-charging capacitor. We had some concern about dust ignition, but simple human annoyances (and bad language) were enough to motivate the grounding exercise.

        Any conductor will work – steel fence wire is find if copper’s too expensive, and if you search “dust collector grounding” you’ll see that there are kits for this – mostly spools of bare wire to run through the plastic ductwork, and grounding clamps. It’s a pervasive problem, particularly during the cold, dry winter months of the northern Midwest.

        1. Had that happen the other day. I was cutting laminate for my hallway floor, and had the shop vac hose tie-wrapped behind the saw blade. Cut a few boards, went around to turn off the vac, touched the hose, and *pop*. Also, mucho laminate dust stuck to the hose in interesting patterns.

        1. And since I can only assume you mean the circuit board material isnt flammable, you would be incorrect. FR-4 boards are often certified to comply with UL94 flammability requirements, for example Phenolic claims their FR-4 boards are UL94 V-0 rated. Which would mean a 5″x1/2″ specimen of a minimum required thickness when placed vertically will self extinguish after 10 seconds. This is very different from a fine dust which would likely be consumed entirely after burning for 10 seconds.

      1. Ahhh, fiberglass. Sorry. Household dust is flammable. Very fine Fiberglass is nasty stuff. I wonder if you could use charged stacked plates as a reusable filter for the fine stuff.

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