DIY CNC Dust Collection Really Sucks!


CNC Routers are great. If you’ve ever used one you know this but you also know that they will cover the machine and everything around it with a layer of dust. It is certainly possible to use a shop vac to suck up the dust coming from the router, however, the only problem with that is the shop vac’s filter will clog with dust and lose suction, defeating the intent of your vac system.

CNCdust-assembled2[Mike Douglas] was ready to step up his CNC game and decided to make his own dust separator. This design is extremely simple and only uses a couple 5 gallon buckets, a few PVC fittings and pieces of wood. To keep the cost down and the style up, the accompanying ‘shop-vac’ is also made from 5 gallon bucket with a vacuum lid. The project is well documented so head over to his site and check out the build process.



A dust separator does exactly what its name implies, it separates the dust and debris from the air before entering the vacuum. The following diagram shows how it works: First, a vacuum creates low-pressure inside the dust separator. That low-pressure draws the dust-filled air into the dust separator. The inlet tube directs the incoming air tangent to the circular chamber. Large debris falls quickly down past the baffle and into the collection chamber. The dust enters and is thrown against the walls of the separator as it spins around. While the dust is traveling around the circumference of the separator, gravity pulls it down into the collection chamber. The now much-cleaner air then travels up through the outlet to the vacuum.

Now that we have a dust separator doing its job, would you want to stand beside your CNC machine holding the vacuum hose collecting the newly created dust? Probably not. Neither did [Gerg], and that is why he made a dust shoe for his ShopBot. It is made from scrap polycarbonate that was kicking around the shop. There are two main components of the design, the top part that attaches to the router and the bottom part that has the skirt. The bottom piece attaches to the top with magnets which allows the skirt to be removed quickly so that the tool bit can be changed easily. And in case you want to make your own dust shoe, [Gerg] has made the dxf files available.


23 thoughts on “DIY CNC Dust Collection Really Sucks!

  1. I use a Dust Deputy connected to a shopvac in my wood shop. It works really well. For my cnc I made a Thien baffle separator out of a 5 gallon bucket connected to a slightly smaller shopvac. I think the Dust Deputy works better than the Thein. I only spent less than $10 in PVC fittings to make the Thein. It works good enough so I don’t plan on buying another Dust Deputy.

  2. The dust collector I am building is much easier.

    Behind the apparatus, saw or router is a catch device the length of the device.

    It is shaped like this
    | |
    __________ | |
    \ \ \
    \ \ \___
    ____/ ____/_________|
    Coarse dust

    Although the fins are solid pieces and longer so that the heavy particles hit the fin, and fall to the catch areas while the air is routed around each set of fins, then out a final thin particle filter, not much different then separating uranium 235 and 238 using a laser while in gas form, and using the difference in mass to move the heavier particles to a different location.

    Patent Pending.

    Then instead of having to pull air into a vacuum, a fan just blows air across the work surface.

    And on a side note, that you should agree with
    since I know Pat the Ent, then that gives me legal rights to all patents.

    Since I can easily show that the idea of patents, was first from the idea of
    Pat the Ent, or what is sometimes referred to as Pa T.

    Giving all English written patents to The Wizard of Oz, Green,
    and that is clearly I RE Land.

    My initials.

    Any questions?

    1. Shape without spaces removed

      …………………|…. |
      __________ |…. |
      ………..\…….. \……\
      …………\…….. \…….\___
      ____/ ____/_________|
      ………Coarse dust

      Robert Eastwood

      1. That is side view, top view looks like the twilight zone swirl in a cone,the shape is the cap on the tin man with a swirl pattern where his head would be,
        Where instead of one area where heavier particles move towards the walls, there are many as the air swirls through the channels.

        Abrasive surface on walls slows airflow at those locations, allowing for more drop to screen.

        This would of coarse indicate that the Tin man has a Twilight Zone mind.

        Of coarse, that is because just like Pa T is an Ent, T In Man. is the reason for tin man
        Just so it all makes sense.

        1. heh, if you knew how many visual graphics I have posted that have been ignored, you would not make the comment that that would make a difference.

          But your welcome.

  3. Never saw the Shop-Vac “lid” thing before – that’s interesting on it’s own. Even more so since the “design” seems to have come around full circle, in a way:

    The earliest “Shop-Vac” I have thus far found was in an old Popular Mechanics magazine from the 1950s or so – which detailed the construction of a vacuum for the shop, with a label reading “Shop-Vac” on the side of a 5-gallon metal bucket (IIRC) which served as its dust/dirt collector.

    Not long after that article (which later appear as a project in the “Popular Mechanics Encyclopedia” as well), the Shop-Vac was being sold as a product. I have never been able to figure out whether the link was a coincidence, or whether the product came from the article…

    1. Shop Vacs are an incredible money making scheme because if you use them for what they are intended to do with no modifications you quickly kill them necessitating the purchase of another. Just something to do with running fine abrasive particulate matter through a high speed motor I suppose.

      1. All “shop vacs” have the impeller in the exhaust not intake, you must be thinking of older designs. Even the old Hoover upright had the motor cooling fan in a separate path, though dirt passed the impeller. The only way to run dirt thru the motor would be no bag in an old Electrolux.
        The main problem with “shop vacs” is NOISE SELL$, why spend any effort making something else! This includes the noise of cheap bearings, lack of balancing, no muffler. Muffler!? Yeah! Try driving with out one.
        Kudos. Multistage pickle buckets. Pop Sci or one of those ran a feature like shop tips and one of them was a pickle bucket prefilter for using any vac as a wet vac. Somewhere in the 70’s. The 5 gallon buckets weren’t in hardware stores but came from fast food discards.

        1. I’ve driven without exhaust. Both accidentally, and by design. Results are different. I also happen to possess three shop vacs (two name branded, one Craftsman). One has severe bearing issues. Which if I do not service it causes it to emit a howl the likes of which I doubt you’ve heard. It has been my observation opening it up in order to service it that contrary to your claim otherwise, plenty of debris enters the motor housing of a typical Shop Vac. Whether the motor is in the input stream, or not.

      1. have you seen how much dust there is with drywall? and that’s reactive with the water. I’m going to give it a go, since I’ve got the dust eliminator already and I’m getting the CNC. Could be you’re right, but with what I’m doing on drywall projects I go 2 to 3 hours between cleanouts.

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