Cyclonic Dirt Separator Using Off the Shelf Parts





Introduction: Cyclonic Dirt Separator Using Off the Shelf Parts

About: When I was a boy, I was amazed how my grandfather could make flotsam and jetsam into useful things. I am proud that I have inherited some of his skill.

Whether or not I need something is beside the point. The question is 'Do I want it?'
While in the process or setting up my workshop, I read quite a bit about the Cyclonic Dirt Separator - a device that allows the heavier particles of debris, such as wood shavings or sawdust, to settle to the bottom of a container, while the finer particles go into your vacuum's filter.
I had to have one.
But I didn't particularly want to spend a load of money or fabricate individual pieces. So this Instructable was born, using (almost all) store-bought parts.


Step 1: First - a Container

The container was no big deal - I merely used a couple of five gallon buckets I already had. If I had to buy them, they would have cost about $5 or $6. I did have to buy the two lids, at a mere $1.25 each.

Step 2: The Input

The cyclonic action begins with the dust being sucked in the top container through a hose connected to the sice of the container, giving it a spin. I already had the rubber boot from a whole house vac, but I wouldn't recommend buying one for several hundered dollars and throwing everything away but the boot. Just select a piece of PVC pipe your vacuum hose will fit into or around and cut the end on a 45 degree angle.
Using the pipe as a guide, trace an oval outline on the bucket that the pipe will slide tightly into. Drill a hole through the bucket and pipe and insert a screw of the minimum length necessary to connect the two together (with the pipe slid inside.) Use silicone caulk to seal the joint.

Step 3: The Suction Part

As shown in the photo, cut a small block of plywood and fasten it to the center of the bucket lid. Using a hole saw or jigsaw, cut a hole through the plywood and lid that another piece of PVC pipe will tightly fit. Again, caulk with silicone. Use plenty - It is what holds the pipe in place.
The hose from the vacuum goes here. The pick up hose goes to the side connection. You have to come up with a second hose for this; I used a pool skimmer hose that I had. Then again, I keep all kinds of junk - you may not. In that case, you will have to buy something that fits.

Step 4: The Bottom of the Top Part

In other instructables, I have seen where the author had molded plastic into a funnel shape. I had no intention of doing that - the point was to use things easily obtained, and in my case, things I already had. I already had a 10 - 8" air conditioning reduction fitting. With the sides of the bucket slightly sloped, and with the fitting almost as wide as the inside of the bucket, it sort of resembled a funnel. Sort of.
I cut a hole in the bottom of the bucket with a sabre saw so that the small end of the fitting would fit. Then using Great Stuff foam, I foamed the inside, around the fitting in the void. It really did have sort of a conical appearance when I got done.
So much for the top container.

Step 5: The Top of the Bottom Part

This part is simple enough. Cut a hole in a bucket lid the same size as the air conditioning fitting. Snap the lid to the bottom bucket.
That's it.

Step 6: Put Them All Together

Set the top part on the bottom part with the metal piece sticking through the hole.
Use a bungee cord to hold them together.
Hook up the hoses.
Note the pile of dust, dirt, and foam on the floor. It will be gone soon.

Step 7: Turn It On...

and the big stuff winds up in the bottom bucket. The smaller stuff winds up in the vac filter. It obviously works.
Two small problems. The assembly hardly weighs anything. I keep pulling it over if I don't chink it somewhere when I am using it. And, secondly, the bucket holds only five gallons, obviously. I have never vacuumed up five gallons of anything at once but it stands to reason I might, over a period of time. There is no reason why the bottom bucket can't be replaced by a larger - twenty gallon, for instance - drum. Also, however much the bottom container holds, you still need to check the vac filter occasionally, That's where the fine dust goes, and that plugs up the filter quickly.
That is pretty much that. An easy project that actually works, costs almost nothing, and uses things you probably already have, if you are a hoarder, like me.



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    29 Discussions


    1 year ago

    You know, it's too bad that like libraries where we borrow books, that we don't have exchanges where we can swap, or order junk parts when we need these kinds. Maybe I'm thinking of flea markets, but a lot of needed parts no one would think of taking to a flea market. Kind of like an maker/creator recycling center maybe?

    mix a small batch of concrete or plaster in the bottom bucket.
    let cure.
    Instant fix to the low weight problem, without making it unmovable
    (10-15 lb free-weight plate should work ok too.

    An unintended benefit to this design is, it makes your standard shopvac into a high-class wet/dry shopvac!

    3 replies

    Occam would love your idea of using the bottom as a concrete mixing bowl and them simply leaving it to harden in place! Nice and clean. Pun fully intended.

    good idea.

    I'd probably just get a small import brake drum from the scrapyard pile, but even some round smooth rocks would work.

    That's a good idea. I probably have an odd weight I could use. I had also thought of doubling up on a triangle or square of particle board and using wheels on it.

    You are right about the wet/dry benefit. I haven't tried it, but I would think it would keep your shop vac dry while sucking up spills.


    Any issues with static electricity buildup?

    You could try putting a spiral in the top bucket like the one pictured here

    . I think you could make one from another bucket lid


    you can put a legging or something over the dustfilter it will keep the filter cleaner ond easy to remove the dust

    What is the advantage to having the larger vs. smaller pieces separated? What's wrong with having them all in the same container?

    1 reply

    It depends on what your are vacuuming up. In typical workshop applications, you get a very fine dust that winds up in the filter, a coarser dust that goes into the bottom of the shop vac, and a bunch of splinters and larger stuff that goes in the bottom tank. Separating the debris allows you to run the vac a lot longer before dumping it, and if you mount the cylonic part on a large (20 gal or so) container, it may be months before you have to dump that.

    You're right. That is a good substitute for the one I used. Thanks

    Very nice, simple design! Where did you find the black, hose fitting mounted to the side of the bucket...that's an especially nice detail.

    3 replies


    I got the fitting off of a whole house vac that had kicked the bucket. It does make it a lot nicer. I haven't found any where to get a similar fitting, sorry to say.

    "I already had the rubber boot from a whole house vac, but I wouldn't recommend buying one for several hundered dollars and throwing everything away but the boot. Just select a piece of PVC pipe your vacuum hose will fit into or around and cut the end on a 45 degree angle."

    A cyclonic separator is a huge improvement for any shopvac, and it really saves the filter and prolongs it's life. One thing I added to mine is on the bottom bucket, I cut a slot app. 2" wide and from app. 4" up from the bottom to app. 6" from the top, and added a clear plastic window to the inside, using # 10-32 round head screws with flat washers. I also sealed the area where the clear plastic and bucket meet with clear RTV. You then can keep an eye on the level of debris and dump it before it gets too high. You are to me complimented on what you built, and I hope to see more of your suggestions and projects. Good job.

    I wonder if adding an elbow to the input side pointed downwards to put more distance between the input and the suction. Maybe giving gravity more of a chance to work on the debris.

    1 reply

    The inlet isn't aimed at the outlet, it's aimed into a spiral to create a vortex.