Home > CNC Machine > Cyclone Dust Extractor

Cyclone Dust Extractor

Before I start cutting again, I need a dust extractor to go along with the vacuum. The filter on the shop-vac was clogged with the dust I created from the first run so much it lost suction. Instead of spending $10 every few minutes on filters, I made a cyclonic dust extractor for the same amount. Since anyone with a CNC machine that cuts has one, there are plenty of plans online. I looked at a couple using a 5 gal. bucket and some PVC fittings that looked easy and went with that.

The $10 cyclone dust extractor.

The input to the extractor comes from the CNC machine and to a 90 degree elbow pointed toward the inside wall of the bucket. Then the output to the shop-vac is a single straight piece of PVC pipe, with the end inside the bucket higher than the elbow. Nothing complicated and parts were easily found at the big box store; 2″ PVC pipe section, elbow and two couplings and a general purpose bucket with lid. The hard part was trying to match  the two different hose diameters.

Dust filled air enters through the elbow, then falls due to gravity and letting the cleaner air continue to the shop-vac out the short pipe.

After gaining a third section of hose, sacrificed from a junk vacuum in the basement, I was able to make a permanent connection to the shroud and bungee cords. The shop-vac hose hooked to this new hose like it was meant to be, but was a trick to find a compatible PVC piece for the opposite end. I used my dremel tool and ground a step into the inner diameter of a section of 2″ PVC pipe to allow the shop-vac hose to fit into. I’ll still be able to disconnect this section to use the shop-vac for cleaning elsewhere. The last section of hose was an extension kit I bought for a different brand of shop-vacs and was naturally incompatible.  One end fits into the vacuum’s input well enough, but the opposite end to the extractor wasn’t near anything. I wound up cutting a slot on one end of a section of 2″ pipe and squeezed the end together with a pipe clamp till the hose fit over. Once the hose was on, the pipe clamp was released and any remaining holes taped over.

The PVC pieces for the output. The two pieces on the bottom are from one coupling cut in half. The smaller half on the right is then cut through perpendicularly to the end.

With the all the fittings made, they need to be connected through the bucket lid. The two holes were cut with a craft knife and care needs to be taken not to rip the material, because it’s easy to do. I scrapped a lid trying to epoxy the two PVC pipes in place, with both times breaking off immediately when moved side to side. Next I sandwiched the lid between two edges of pipe coupling that worked well. For the output section I cut a coupling in half, then cut through perpendicularly on only one of those halves (just one cut so it stays a ring, but opens wider). The solid coupling half goes on the straight pipe section, inside the bucket. On top of the lid, the cut coupling half can expand around the pipe to go all the way down easily. The PVC cement seems to melt the lid material to the pipe and fuses everything securely (and gives off some bonus fumes). The input side also needs a coupling cut in half, but only the piece with the extra cut like before; the edge of the elbow serves as the bottom part of the sandwich.

Only half of a coupling is needed for the input side, cut to go over the pipe easily.

Once the glue dried and the hoses were connected, I fired up the vacuum to test for leaks. Where hoses met, I sealed with duct tape. Then sealed leaks in the PVC/lid area with some silicone. While the vacuum was on, the wet silicone sucked into holes. I also revised the bungee cord rigging to hold the hose off of the work surface. With the gantry at is furthest position, the bungee cord was wrapped around the hose a few times and held in places with zip ties. When the gantry moved back to home, the hose naturally coils against the wall and out of the way. From the pic below, it looks like the cord is pulling hard on the hook in the wall, but there is still some slack left.

It worked! Some of the dust made it past to the shop vac, but not as much as this.

Eventually, I’ll move both the dust extractor and vacuum in the basement, with the switch controlled by the CNC software. But that will have to wait till I actually make something.

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  1. April 10, 2012 at 3:57 pm

    Awesome! I found a vacuum the other day and fixed it up just for something like this. It works and has tons of suction and i can also use the other side to blow as well. Ill be sure to make one of these buckets. I can get buckets for free. Have you thought of getting a simple sifter like for sifting flour when cooking and cutting a circle out to use as a file in the smaller pvc this would allow you to simply wash off the filter and can be used a ton before a new one is needed. And also can be had for $1 in most (99Cent) stores.

  2. April 10, 2012 at 3:59 pm

    file = filter…. huge typo 🙂

  3. April 10, 2012 at 4:44 pm

    Anything that filters just clogs with the fine saw dust. I might try something like that later, but it worked well enough. I only made a couple passes the first time and the dust filled the grooves of the shop vac filter to the outer edge and lost suction.

  4. April 10, 2012 at 5:50 pm

    Check it out:

    Would something like that work?

    • April 10, 2012 at 6:02 pm

      The dirty air needs to make a turn to hit the side so the particles lose momentum and fall out of the air. Just add an elbow to the input side and it should work.

  5. April 10, 2012 at 6:16 pm

    forgot to mention that. I dont know how to do elbows in Sketchup 🙂

    • April 10, 2012 at 6:23 pm

      Ha, yeah me neither. I’ll be playing with it eventually, for now I’ll be busy with CAD and EagleCAD. I have all the supplies for milling circuit boards.

  6. Nova
    April 11, 2012 at 3:04 am

    It is very nice and useful for me…
    Thank you…

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