Ultimate DIY Cyclone Build Thread

[HeadScratcher]

Since I have changed the single 6" side inlet into three 4" top inlets I am wondering if I need to change the design a bit like this... Thoughts, comments, suggestions???

[doug3030]

have we just gone through two threads of about 100 posts to come back to reinventing the single cyclone?

[HeadScratcher]

Gaza I wouldn’t know where to start with computer modelling but I find that most of my ideas do tend to work quite successfully, so it is more guided by a sense of logic.

Doug I still think the triclone has a lot of merit and I don't plan to change the basic design, my question is more around the top section of the of the cyclone. Figuring if it top feeds the dust is more likely to fall out of suspension if the walls are parallel, but if there was a constant taper from the top lip (like the Cyclone Central), the circumference is constantly reducing, keeping velocity up.

I guess my question comes down to the need for a parallel walled section… Is this done to keep the top tapered section of the cyclone down to a reasonable size?, or is this just a cheaper way of manufacturing the cyclone? To create a taper all the way to the top uses far more material then rolling a tube and putting it on top of the taper.

Also the way I have done the top section where the three inlet come into a common area, that is the equivalent of the parallel wall section anyway, it just has three cyclone sitting where there would normally be one. Nothing ventured nothing gained…

[HeadScratcher]

Got around to cutting the main 150mm pipe to length today. Also decided to shorten the three 150mm cyclone tubes. I cut them to half size (225mm long) which leaves the cones down about 30mm from the top.

I haven't shortened the three 100mm pipes yet and that is why it is sitting up still. Have gone backwards and forwards on letting it sit up a tiny bit for better cylinder filling, but that might affect the swirling action.

Tools Used:
Grinder and file.

[HeadScratcher]

Discovered a fundamental flaw in the design that didn’t get a consideration in the design thread… While I was busy trying to match the pipe sizes to have equal flow there was one major thing that was overlooked.

Equal flow is fine if you feed all of the available area (which is not technically possible in a top feed) In the regular cyclone the dust is feed into one side of the dust collector and while it does allow all of the dust in the collector pipe to enter the main pipe chamber it does come at the cost of making the chamber wider than would be optimal to maintain the strongest vortex.

By using a top feed (dust coming in from above), if greater than one small portion or side of the tube can be filled at any one time, it would allow a more even flow and greater flow rates. While playing around with different ways to maximise the intake of dust I come to realise there is no way to get 100% fill as you can’t have both the intake and outlet exiting the same top section, without one or the other crossing its path. The best I can come up with is something like an engine valve in an intake port.

I have made a few alterations to my design to fix the problem. I would go from 100mm pipe (105mm OD) back to 90mm OD pipe.

[surfmat]

c'mon the tension is killing me..... hows the build?

[HeadScratcher]

Sorry in a bit of a holding pattern at the moment. In two minds with which way to go with the DC. I can mount it on top to remove the 90 degree bend, or I can build the DC into its own cupboard to mount it up high and supress the noise a bit more. Still trying to work out which is the best for my situation.

[BobL]

, or I can build the DC into its own cupboard to mount it up high and supress the noise a bit more.

Do you mean build the DC impeller and motor into it's own cupboard to suppress its noise? If so it will need it's own cooling and thus baffles to let air in/out but keep noise in. I think we have discussed this before but just checking.

[HeadScratcher]

Just the impeller section... so inlet side would be a square piece of MDF with a 150mm hole cut in the centre to poke the inlet through. Same for the outlet side. The motor side I would probably use two pieces of MDF with a semi circle cut in each and sandwich the motor so the motor and impeller are separated by an MDF wall.

Just an initial idea still formulating it...

[HeadScratcher]

Ok knocked up a first draft of what a stand might look like. I was thinking of a box within a box... Inbetween the two walls fill 5 out of the six sides with expanding foam.

[HeadScratcher]

Going back to drawing board once again. A few post ago I mentioned that I got the sizing of the outer pipe wrong. I was looking at making the inner and outer pipes equal volume but failed to factor in that it wont fill the outer pipe 100% from the top.

So where does that leave me? Well I either need to buy some bigger pipe (8 or 9") or build something myself. It also means that I need to redo the centre section because that design was predicated on using the 6" pipe, and having the pipes central.

I did a quick mock up to see what it would look like if 90mm and 100mm pipe but it will offset it to much to one side with the 90mm.

I was also thinking about making three separate cyclones since I will be using three 4" hoses to pick up the dust.

[HeadScratcher]

I should point out I am not completely starting from scratch I am just backtracking a few iterations to when I was looking at using the 45 degree bends blended into the centre section. Now that I need to space the clean pipes away from the centre a bit more this is the more logical way to go. I was hoping to try make it so anyone with limited skills could duplicate what I am doing, but it will be quite tricky to blend three pipes into one at a 45 degree angle.

I was thinking about getting three 150mm x 100mm plain junctions with 45 degree bends, and just cut 1/3 out of each 150mm pipe and join them together. DWV FITTINGS - DWV JUNCTION - Perth Irrigation - Retic Fittings , Plumbing Fittings, Reticulation Supplies, Western Australia
But at $60 for the three bends it defies the cheap aspect of the build.

[doug3030]

Thanks, that photo just saved me an hour's work on a totally unrelated project.

awesome!!!

Doug

[HeadScratcher]

Glad to hear my posts are useful for something besides entertainment

Based on the theory that the less bends the better, and smaller bends are better than a big bend (2 x 45 is better than a 90 – BobL quote). I have revised the outlet section once again.

Since I plan to have the DC to the side of the DE this would seem to be the optimal way to my thinking. I can still make the top clear to observe the dust movement.
Also rethinking the use of outer pipes like in the first design. If I go with much bigger witches hats and I glue them to the plastic top, and I use the holes in the bin lid to stop the bottom from moving around, and use some threaded rom to hold them down, I can simplify the design quite a bit.

[Lplates]

Hi HeadScratcher,

Just a quick hello to say thank you for the comprehensive write up. Just wondering if you are working to a given design or if you have come up with something based on your experience?

I love to see this sort of "garage engineering", good to see you aren't afraid to take on a challenge like this. Keep up the good work and I hope you can post of video of this thing in action once it's complete.

Cheers
Mat