Project concepts & ideas #1: Alternative to cyclone dust collector?

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Blog entry by TheLandYacht posted 07-23-2009 08:43 AM 4192 reads 1 time favorited 11 comments Add to Favorites Watch
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OK. As I’ve understood it, the point of a cyclone DC is to slow the air movement down to allow the dust to fall into a receptacle before the air to move into the blower. Am I right on this?

So, my concept is this. Instead of a hard-to-assemble cyclone setup, just a 5gallon bucket, with a smaller (1 gallon or so?) bucket mounted inside of it…with the below modifications. Lets see if I can describe my concept well enough not to need pics & sketches.

So. A 5 gallon bucket with the inlet side pipe coming in at about a 33degree downward angle & angled to the bucket in such a way that the incoming air will naturally “swirl” around the periphery of the inside of the bucket.

“Vanes” made of (not sure what material). They don’t need to stick out far from the sides of the bucket, maybe an inch. Three or four of these running from the top to the bottom of the bucket. These vanes will cause the air, which is coming in & swirling around the periphery, to slow down considerably, which should allow the dust to settle to the bottom of the bucket.

On to the 1gallon bucket. Like the 1gallon buckets you get ice-cream in at the grocery store. First, perforate it. A LOT. several dozen (drill) holes of undetermined size in sides & bottom of the bucket. Then seal the lid of the 1gallon bucket to the bucket using silicone/etc. Mount the 1gallon bucket&lid to the center of the inside of the 5gallon bucket lid. cut through both lids a hole the size to insert & mount the “suck” side pipe through the lids and about 1/3 of the way into the 1gallon bucket.

Attach vaccuum/etc & use.

Anyway, does my idea have merit or am I fartin in the wind?

Or do I have the entire concept of the cyclone DC wrong?

11 comments so far

View patron's profile


13524 posts in 2762 days

#1 posted 07-23-2009 09:31 AM

fart in the bucket ,
to be on the safe side !
doesn’t sound to hard to try ,
give it a ” whirl ”.
keep us posted .

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View jockmike2's profile


10635 posts in 3667 days

#2 posted 07-23-2009 01:24 PM

That sounds better than what I got. I bought one of the small tops from Rockler and it has a 45 degree pipe 4” on the inside top pointing downward, but my Rigid 5HP Vac sucks the material right out of the 45 pipe and into the Vac. So I need to get the 5 gal. bucket up higher so there is room for the air to circulate, and hopefully not get sucked up into the vac. Other than that it does increase the suction of the vacuum when it works right. I think I’m going to cut the bottom out of another 5 gal bucket and hot glue it into the first one.

-- (You just have to please the man in the Mirror) Mike from Michigan -

View jerryz's profile


164 posts in 2699 days

#3 posted 07-23-2009 01:39 PM

Actually the cyclone has nothing to do with air slowing air as it has with imparting angular motion to the dust contained in or transported by it, and it is very dependent on particle size and air velocity.

The principle is similar to an atraction you find in most malls where you put a penny or other coin and watch it disappear at the end of the funnel.

In the case of the cyclone you want to create that vortex efect so that the particles hug the inside surface of the cone and gravity then can do it’s thing and the particles fall to the bucket.

The lenght of the cone, it’s diameter and the air velocity all contribute to set the particular characteristics so that you can anticipate up to what size particle will be effectively be removed from the air stream.
You can find online all the formulas to design your own cyclonic dust removal system.

Have fun designing one, after all it is not rocket science….

View PurpLev's profile


8523 posts in 3069 days

#4 posted 07-23-2009 01:45 PM

you have the cyclone idea somewhat right, but you forget the concept of airflow.

the beauty of the cyclone concept, is that it eliminates torbulances in the chamber, and creates a clean airflow that makes sure the dust is sent to the bottom of the container, and doesn’t get disturbed and brought back up (where it will be sucked into the impeller).

check this one out:

this is a simple and effective solution that directs the dust down the container and prevents it from being sucked back up but without trying to “stop” the airflow like you are thinking of doing.

and yes – the Lee valley, rockler, woodcraft, etc “cyclone lids” all lack in the design and performance.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View tenontim's profile


2131 posts in 3165 days

#5 posted 07-23-2009 01:59 PM

From your description, the part about the all of the holes in the smaller bucket is where you’re going to loose your vacuum efficiency, by causing quite a bit of turbulence in the flow. It should cause the chips to fall out, but it will reduce the amount of vacuum.
That’s my non-rocket scientist opinion, but like Patron said, give it a try.

View Don Butler's profile

Don Butler

1081 posts in 2816 days

#6 posted 07-23-2009 03:31 PM

If the shopvac is sucking everything out of the collection chamber the air velocity is too high.
Using a larger diameter pipe/hose between the collector and the vac should result in a similar air volume, but should drop the velocity, allowing chips and heavy particles to stay in the collector.

I have a transparent connecting hose between the cone and chip collector in my cyclone system, so I can see what’s going on at that point. I see the dust and chips whirling in the center of the pipe before dropping out. It seems to me that as material approaches the middle centrifugal force is less and it drops down due to lack of that force.

Did I get that right?

I’m not a rocket scientist, so I may be thinking wrongly.


-- No trees were damaged in posting this message, but thousands of electrons were seriously inconvenienced.

View John Ormsby's profile

John Ormsby

1283 posts in 3158 days

#7 posted 07-23-2009 03:54 PM

Yo might want to take a look at these short videos from Clearvue cyclones to get an idea about their actions. Look especially at the slow motion CV06 and sucking up a 25’ tape videos.

-- Oldworld, Fair Oaks, Ca

View rustfever's profile


716 posts in 2731 days

#8 posted 07-23-2009 05:01 PM

Go to this web site and learn about dust collection systems. This gentleman has done a great deal of research and development on dust collection for the woodworker.


-- Rustfever, Central California

View SteveMI's profile


946 posts in 2715 days

#9 posted 07-23-2009 09:36 PM

I built a seperator based on Phil Thien info and it works fantastic. Made it from two plastic pails in a day. Sabre saw and drill were only power tools, plus a glue gun. Total cost was under $20.

The clearvue and Bill Pentz products are geared to larger shop. I have a 1.5 hp, 6” hose air vac, but it wasn’t any good for 1.5” tool outlets. A lot of air is moved, but not much suction.

After the pictures, I added a rubber o-ring between the pails and put some small bungee cords from the studs on top to bottom of lower pail.

Before building this I needed to clean my shop vac filter every 30 minutes of use with MDF and every 60 minutes of use with plywood. Cleaning the filter each time took 15 minutes itself and the MDF was a special pain. Now I can work 6 to 10 hours between dumping the bottom pail in less than 5 minutes and the shop vac filter is spotless. The air is noticeably cleaner.

So, here are some of the build pictures;

Or maybe not. I need to learn about posting pictures at this site. I am not a fan of the online picture sites due to the seemingly instant 100 new friends that send me emails about enhancements to my body parts.

I’ll see about the project area and link to that if I can figure it out.


View PurpLev's profile


8523 posts in 3069 days

#10 posted 07-23-2009 10:05 PM

Steve, you cracked me up with the enhancements body parts emails…. I’m in the same boat… not a big fan of signing up to too many sites (this one here is special). good idea about posting it as a project though, and linking to it from here!

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View SteveMI's profile


946 posts in 2715 days

#11 posted 07-23-2009 10:42 PM

I now have a project posted for my dust separator!!

Only six pictures, but they will give the idea. Below are a couple of the “links” or just go to projects.

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