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Cyclone build part 5 – Putting it Together

Now we have our upper body and our cone, it is time to put it all together, mount it on an air tight container of some kind, hook it up to the vacuum cleaner and test it out. This is the super exciting part, where you get to watch the dust speed gracefully to its new home.

Before fitting the cone to the upper, with a sharp knife I cut the bottom edge of the upper body at an angle, so that when the cone is fitted against it it forms a seamless join.  This way, on the inside, where the cone meets the upper there is no lip or disturbance to disrupt the smooth airflow.  Once that is done I hot melt all the way round to make a strong and airtight join.

Then we just need to get a suitable hole in the dust collecting container and glue that up.  Here, because I wanted my finished height to be lower than the total height of the cyclone + the barrel, I made a slightly bigger hole and sat the cyclone lower down. This has the added advantage that the whole thing is a bit stronger and more stable (not that it matters much in this case because it will be mounted to a solid side of the DS’s enclosure.

That bit of half pint glass is stuck on the bottom of the cone to make the dust chute. The cone is then stuck into a hole made in the lid of the barrel. I chose to have it poking this far down so that the finished assembly was not so tall. But to make most of the barrel you could have it stuck right at the end.

As  mentioned, the mounts you see will attach to a side wall of the dust sniper.

After all that I don’t believe anyone would be able to resist bodging up some vacuum hose connections and trying it out immediately.  I used a liberal amount of duct-tape and a washing up liquid bottle to connect the hose up and gave it a whirl.  Result: no dust going to vacuum bag and dust in collection barrel remains undisturbed even when the vacuum is on.  In short, we have swirly helter-skelter style dust extraction – wooha.

So the rest of the dust sniper project can be found here on instructables. If you found this interesting please share the love and like our facebook page, on which you can see what else we are making.

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Responses to Cyclone build part 5 – Putting it Together

  1. Bill Pentz


    Thank you for the kind words and you have done a great job with your write up. Are you ready to help me redo my pages?

    Bill Pentz

  2. Bongo

    Hi Bill,
    I will help if I can. Ironically I spent most of yesterday struggling over the comment code, not achieving the desired result and getting very frustrated… Anyway, I have e-mailed you a proper reply….

  3. Steve H

    I hope this posting works, made another earlier and has not worked – anyway, love the posting, great breakdown! Have tried a few different versions, mainly based on a drop out style.

    I was unsure about the ramp, but now having looked at it several times, I understand why the ramp is fixed at the top, making a sealed pathway inside the unit, as I thought it should be at the bottom of the inlet – a ramp!

    Purchased some styrene over the weekend, hope this works as well as the polycarb you used, will let you know how I get on –

    Hobbyist woodworker.

    Keep up the good work – Steve

  4. Bongo

    Hay Steve,

    Not sure why there should be a comment problem- it all seems to be working. Maybe I was tinkering with the code when you tried last, sorry.

    I was just going with the convention, but now you point it out I can see how the ‘ramp’ could be confusing.. I think it should be called an ‘air slide’ or ‘helter-skelter’ ;)

    I don’t know much about styrene, what made you choose that? I heard that PETG thermoplastic polyester might also work, being nearly as strong as polycarb but easier to machine.

    Can’t wait to here how you get on.


  5. Steve H

    The reason for choosing clear sheet styrene is that it is readily available from the ‘big sheds’ for shed windows etc.

    It appears to cold bend relatively easily although I have not tried to push it too far just yet.

    Interesting name by the way – did that come with your PhD?

    I do a post on a forum on a woodworking site where this quite a bit of interest to cyclonic extraction methods.

    Dust is a problem for everyone and would like to be able to put something together that everyone can do, with the tools that most woodworkers would have in their arsenal.

    I am no expert in – anything really – but thought – if I can do it, they can to!

  6. Bongo

    @Steve H – Ha no, the name had nothing to do with the PhD…

    What is the forum, out of interest?

    Let us know how the styrene works out. What are you using to bond/glue it?

    Agreed that dust is a big problem, unfortunately bigger than people tend to give it credit for.

  7. steve h

    Is it 101?
    The styrene was a disaster and shattered on bending. I made a few prototype cones out of card but could not seem to get the correct cone aperture, even using Bill’s spreadsheet. Time is a real issue for me & I need to resolve this quickly. Time for a nice long weekend break!

  8. Bongo

    Sorry to hear that Steve. What thickness was the styrene? With polycarbonate, your cone needs to be made from no thicker than 0.75mm – like I say, with styrene I am not so sure. If you are pressed for time, maybe just copy what I did here, I know that works.

    Otherwise, maybe experiment with forming your styrene using a heat source like a hot air gun (this is difficult with polycarb because it absorbs atmospheric moisture so quickly, which makes it all bubbly and uneven). But to do that you will need to make something of correct dimensions to form it round – you could maybe knock something up with a big lathe or use a bandsaw to make a number of circular layers that you could stick together…

    This may help, it is a quick plastics comparison:

    In terms of actually making the right shape for the cone, it shouldn’t be too hard. Just mark out one complete circle of radius 390mm, and another smaller one inside that of 125mm.
    Cut around both circles, and cut a straight line through the radius of the circle. From this line and the centre, use a protractor to measure and mark the circumference (like a clock) every 71 degrees – now when you roll up your cone, just line up these marks…

  9. Adam


    thanks for such a detailed write up on the build. I was thinking about something like this not so long ago, but I didn’t think I would get it to work. I really want to try this now! You’re Instructables write up mentions some google shetch-up diagrams. do you have the sketch-up available for download?


  10. Bongo

    Hi Adam,
    Thanks for this. Yep, will do soon – check back in a day or two for the SketchUp files.

  11. Ram

    Hi. I just saw the dust cyclone. I am currently doing a project on a deoiling hydrocyclone which is used to seperate oil and water from bilges. Would it be able to do the same function as the Cyclone Dust seperator?? Can i use the same method?

  12. Bongo

    Hi Ram, I am no expert in deoiling hydrocyclones, but from my (little) research they appear to require quite different geometry. The cyclone here uses proportions designed for fine dust extraction.

    In some ways it seems deoiling water has similar difficulties to wood waste cyclones, in that the efficiency of a specific design will vary depending on the nature of the materials being separated. One cyclone that is excellent for large particles of Oak dust, for example, may not work so well when separating out super fine dust from a lightweight wood like pine.

    Presumably because your hydrocyclone is going to be a ‘deoiling’ one there is a much larger proportion of water than oil in the mix? You will want to design your hydrocyclone to with this average ration (water:oil) in mind – so taking measurements of this first would be a good plan.

    Some systems try to get round this problem by having sensors to determine the proportions of oil in the water before they enter the hydrocyclone, and adjust things like the speed of the pump to try and improve efficiency.

    So I guess that’s a long winded way of saying NO, this cyclone design would probably not work unmodified to de-oil water.

    Also, I would be cautious of using similar construction methods (ie. hot melt glue), because oil and other stray chemical like diesel fuel will tend to cause rapid structural failure in such materials.

  13. MSeries

    I have been studying your pages and other pages about cyclonic separation for the last few weeks and the more I read, the more confidence I gain for making one of these. I am also using a vacuum cleaner, a 1400W Draper so I think your dimensions will suit me well, your hoses look like mine too !. Can you possible show some more detail about attaching the hoses to the inlet and outlet ? Did you simply create holes with a tight push fit for the hose ends ?

    Also, can you give us more detail about the hot melt glue ? Is is anything special ?

  14. Bongo

    Cool. Yes this should work for your vacuum.
    As for the hoses, the whole cyclone arrangement was fitted into the Dust sniper, so the air outlet was complicated, because it was acoustically ‘treated’ to prevent noise transmission. But ultimately I had a very short section of hose permanently fixed (ie glued) from the vac to the cyclone, and made a push fit for the hose going to the cyclones inlet. The push fit was a small section of plastic waste pipe, that I tapered using a hot air gun.

    As for the glue I just used the standard stuff they had at the hardware store, but… If I was doing this again I would defiantly spend some time to source stuff that was designed for polycarbonate, as I hear you can get special stuff (please report back if you source some!).
    Saying that the stuff I used worked surprisingly well – I just think it could be even stronger (there was one incident when I banged into it with a heavy timber and broke a seam apart).

    Let us know how it goes.

  15. Jeff

    Has anyone experimented doing this with water? For, say, a pond filter? the suspended solids (fish poo) are of very similar density to the water, so dont drop out easily, but I imagine the principle would work the same.

    Also how does this arrangement cope with sucking up and separating liquids from air, like a wet dry vacuum. id love to see a video clip of that

  16. Bongo

    I’d also be keen to see that. Anyone?

  17. steve c


    Real useful write up on your dust extraction.
    I’ve found that Evo-Stik sticks like sh*t clear adhesive sticks the ploycarbonte very well,it’s not as fast as the hot melt glue, you have to allow over night for it to set.
    Your local screwfix should have it in stock.
    I’ve built a version for my tablesaw using a small 1300watt wet/dry vacuum to provide the suction, it does work but i still seem to have more dust in the vac bag than i expect !!!
    May have to rework the size of the cyclone to over come this, unless anyone knows better.??

    The size is 150mm diameter cylinder with a total of 450mm for the cyclone in height, the input and output air tubes are 70mm flexible air hose, other materials I’ve found via ebay.

    Thanks for brilliant website.
    Steve c

  18. TexasJim

    Hi –
    I found your dust separator on the internet and was inspired to build my own – like yours out of clear plastic so I could watch it work, including a clear hose from the separator to my shop vac. While not the same size, I tried to keep all the ratios as close as possible to yours. When I turn it on, I can see the material swirling down the ramp and through the cone, but there is also material being sucked out through the top to the shop vac. Can you tell me what might cause this? I did not use your half-pint glass on the bottom of the cone for a “dust chute”. Is that necessary? If so, does it flare out from the bottom of the cone, or just extend the same shape of the cone?
    Thanks much for any help.

  19. Bongo

    Sizing is quite important, as are details… Did you use the Bill Pentz spreadsheet to get your sizing? Did you make it bigger or smaller? If you went bigger, there may just be insufficient airflow to get it working correctly…
    The half pint glass is not necessary – there just wants to be a bit of a chute at that point, that worked for me because the size matched the rest of the cyclone…

    Other things to watch for are any little air leaks (particularly in the dust bucket/cyclone joint area) and rough edges which will disrupt the smooth airflow.

  20. voltski hydroco

    I would think that the cone is a perfect candidate for
    3d printing…. what do you think?

  21. Bongo

    Hi Voltski,
    Not sure to be honest, not enough experience with 3d printing yet. My first guess is that it would depend on the specific type of 3d printer and the quality of the print. Vertical ridges (formed by some printers’ layering process) would cause a lot of turbulence and very poor airflow/material separation.
    I imagine that even a good ABS or PLA print of a cone would need a reasonable amount of post printing work to smooth the inner surface. That said, there are printing technologies like Stereolithography, that I really have very little experience of that might be just the ticket??

  22. Timbo


    Greetings from Adelaide/South Australia. Would it make sense to reverse the direction of the cyclone for the Southern hemisphere? I.e. coriolis effect etc.?



  23. Bongo

    Hi Timbo, really interesting question. The truth is I have no idea! My hunch is that it will make no measurable difference, but I don’t know. Hopefully someone who knows will chime in…

  24. Timbo

    Thanks Bongo. In other words, if I make it myself I might as well reverse the direction of rotation – can’t hurt.

    Thanks again for your response.



  25. Bongo

    Timbo. I’m not sure. I still don’t think it will make any difference – and because it didn’t cross my mind, the cyclones I made do not necessarily spin the same way as water down a plug hole. Watch water going down your plug and make it to spin that way I guess – it my well be the same.

  26. Wayne Newton

    Hi Bongo,
    Love the whole design of your Dust Sniper and the cyclone system, my queston is would a (Dust Mite) cyclone work as well as your beautiful creation.

  27. Bongo

    Hi Wayne,
    Thanks for the comment. I’m not 100% sure what a “Dust Mite” is?? Enlighten me, and maybe I can say..

  28. Wayne Newton

    Hi Bongo,

    Here is a link for you to see one but im thinking there is no way it will be as good as your dust cyclone as it doesn’t seen to have any internal spiral cute to help the dust on it’s way to the bin, but any info you could give me would be greatly appreciated.

    Regards wayne

  29. Wayne Newton

    Here is the link.

    Regards wayne

  30. Bongo

    Hi Wayne. Ahh I see. Interesting. Well, it doesn’t seem fantastically designed – no angle to the inlet (which is round – not as good), and no air ramp. No upper body at all in fact. It would probably function much like a drop box – possibly a bit better.
    Personally the hilarious “Remember Agincourt. Buy from a British Company!” would put me off. Where do they think the oil is coming from to make that. I doubt if it is made in England at all for that matter.

    Anyway, that’s a bit irrelevant. The question is, would it be worth the extra air resistance the cyclone would introduce. In the absence of anything better the answer might be yes, but really depends on how you use your vac?

  31. Wayne Newton

    Thanks for your time in this Bongo, after showing your cyclone design to my father in law who is an engineer he was very impressed and said that there is unlikely to be anything as good as your masterpiece for the price you would spend on the materials, (around £35 including glue) which in my opinion is a steal and if I lived closer to your workshop I would pay a visit on an open day and shake the hand of a great minded individual that has changed the world of people who like to make great things for recycled materials, I am in the middle of making a small workshop out of recycled pallet wood. Thanks again for your help and im sure I will bug you again sometime.
    Regards wayne

  32. Bongo

    Ha, thanks Wayne. Bug whenever, questions, comments and input is always very welcome!

  33. Clifford "Cliff." Johnston

    I am looking at buying a wall-mounted shop vacuum that is spec’ed at 92 cfm. Will this be enough cfm to work with a cyclone that is 18″ tall? I’m new to this dust control methodology – really interested & really need it!



  34. Tom Triglav

    This is truly a very impressive design. I had everything but the slanted top piece that will of course direct the air smoothly downward into a nice spiral. Brilliant and simple. No need for those multiple cones on the top as dyson made them. I am going to make it out of steel and use 1000 cfm in 4 inch opening and about 27 inches of Hg. Probably will need a 35 hp engine. It will be able to suck up dirt sand mud etc. The velocities I achieve will be incredible. Hope it will work with water. Any input would be appreciated. Is there a velocity limit other than the speed of sound?

  35. Tom Triglav

    I have been thinking that at the high velocities I will be using the slight improvement in the design is to curve the incoming pipe so that it will match the curve of the cylinder.
    The next question I have is what happens if you suck up some small sticks splinters of wood and larger shavings like I get from my planer and they plug up the bottom hole.
    What happens then. That part just seems to be working on the force of gravity.

  36. Bongo

    Hi Tom, sounds like you have an exciting project. Yep, it is possible to plug the bottom of the cyclone with large bits. When this happens the cyclone will stop working and everything will be sucked up the air exit – where clean air should be going! This needs to be factored into he design. So if you don’t have a material handling impeller, you need safeguards to stop explosive damage that could occur in this instance! This could vary from elaborate auto shut down alarm systems to something as simple as a grate or grill located before the impeller, which might be enough…

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