[black300zx]

For those of you who don't visit ICIX, I built a dust separator to hook up to my shop-vac to (hopefully) keep it from getting clogged up with sawdust. It wound up working great, so I figured I'd share it with you guys.

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After realizing that the amount of dust I'd be making while routing out the pieces for my sub enclosures, I decided to take a crack at making a dust separator to keep my shop-vac from clogging it's filter and killing itself. While my metalworking skills leave something to be desired, hopefully some of you will find some use for this.

A general overview on cyclonic separation

Some more info

The parts - a 6" diameter x ~2' long steel duct from home depot, a 2' long piece of 2" PVC pipe, and a tube of 3M quick cure 5200 adhesive. Total cost: ~$15 + some spare scraps of MDF I had laying around.


The duct was used to make the body of the cylinder, as well as the cone at the bottom. I cut ~18" off for the cylinder, and the the rest was used for the cone.


A paper cone was made, cut out, and traced onto the remaining part of the duct.


The cone fitted (the small end was trimmed afterwards)


A short (~6") piece of pipe was cut off the 2' piece and one end was shaped to contour to the side of the cylinder. It comes into the cylinder tangentially with a downward angle. A corresponding hole was cut out of the cylinder for the pipe to fit into. 3M 5200 was used to bond the pipe to the sheet metal.




To make the top, I simply cut a circle of 1/2" MDF to size, put a groove into the bottom side, and a hole in the middle for the pipe to fit through. 5200 was again used to seal the joint between the pipe and MDF.






I used a 5 gallon bucket to collect the separated dust. To create a tight fitting lid, I cut a 13" diameter circle of MDF, put a 1/4" deep groove in one side (for the lip of the bucket to sit in). A hole in the middle was cut for the cone to fit into.

Test fitting the bucket in the groove:


Cone being test-fit in the center hole:


Finished lid fit onto the bucket, along with an MDF clamping ring that fits from the bottom and rests against the ribs on the bucket.


One key point to keep in mind is that any air leaks will degrade performance of the dust separator. The velocity of the air coming into the separator is key to separating the dust, and any air leaks will reduce the velocity of the air coming in. All seams and joints were sealed with 5200.


A test fit of everything:


Everything glued together:


After all the glue dried, I layed down some foam tape in the bottom groove on the lid. This will prevent air leaks between the bucket and lid.

[black300zx]

Results:


Shop vac insides before the test:




The separator hooked up to the vac, and the "test pile" of MDF dust sitting on the sheet of MDF:


Shopvac after sucking up the above pile of dust:


...and the collection bucket

[Wolvatron]

WHOA!!

That's cool. Big time props, man.

[z-lite]

Originally Posted by Wolvatron

WHOA!!

That's cool. Big time props, man.

I don't know why but now everytime I read your posts I hear you in my head saying it in your voice,

[Wolvatron]

Originally Posted by z-lite

I don't know why but now everytime I read your posts I hear you in my head saying it in your voice,

I hope it sounds as good in your head as it does in real life.

[cptomes]

color me impressed. going to make me one of these... Use it on my blast cabinet.

[black300zx]

I've actually been meaning to try it out with my blast cabinet, as that clogs the shopvac up almost as fast as MDF dust does.

Two things that I've realized over the past 2 weeks of use:

1 - In dry weather, the dust rubbing against the inside of the metal tube gives it one hell of a static charge. It's given a pretty good zap a couple times. If you use a steel duct like I did, I'd suggest wrapping it in something non-conductive. Perhaps a layer of duct tape.

2 - I'd estimate 99%+ of sawdust that gets sucked up winds up in the bottom of the bucket, however what does get through is the very fine dust that would be floating around in the air after you cut up some MDF. The filter on the shopvac will look pretty clean, however a close look will show that it's got a think coat of dust on it. A quick hit with some compressed air ever other use keeps the filter breathing nicely.

With regards to point 2, I'd be surprised if this separator would be as effective at removing the dust that gets sucked out of a blast cabinet. For $15 in materials though, I'd say it's worth a shot.

[pete in atlanta]

Brilliant.

I saw this the other day:
http://www.youtube.com/watch?v=9NXZKYWpMbE

They sell them here for $60:
http://www.dustdeputy.com/

I have Oneida oversized felt bags on my dust collection system and the difference is amazing. My father also has one of their big cyclone units in his shop and that's incredible.

So you saved yourself $45, and more importantly, impressed all of us with your ingenuity.
Rock on man.

[black300zx]

Originally Posted by pete in atlanta

Brilliant.

I saw this the other day:
http://www.youtube.com/watch?v=9NXZKYWpMbE

They sell them here for $60:
http://www.dustdeputy.com/

I have Oneida oversized felt bags on my dust collection system and the difference is amazing. My father also has one of their big cyclone units in his shop and that's incredible.

So you saved yourself $45, and more importantly, impressed all of us with your ingenuity.
Rock on man.

I actually didn't realize the dust deputy was so cheap until after I built this. Before hand, I might have just bought it. After the fact, however, I'm glad I built it myself. That $45 I saved will pay for almost half the MDF for my HT sub cabinets.

[yachadm]

That's pretty good.
I did a similar setup with a gravity drop, when I installed the Central Vac in my house about 15 years ago.
Common problems before were pencils and other objects which had the potential for serious clogging around bends.
Now all bigger garbage goes into an easily emptiable bin, without the danger of clogging up the 2" vac lines. Only small and fluffy stuff makes it to the vac bin.
Nice when science works in practical applications...

[blitzdemon]

5gal bucket...f that, 55gal barrel.

[alexlindeman]

Originally Posted by blitzdemon

5gal bucket...f that, 55gal barrel.

Try moving a 55 gallon drum of MDF dust.

[Inferno333]

Pallet and a forklift my friend.

[black300zx]

55Gal drum would be awesome.....until it's time to empty it

I actually filled up the 5gal bucket the other day.

[cptomes]

5 gal bucket would fill in about an hour in Newton, I would guess.

[black300zx]

The one part of the design that I was a bit weary of from the start was the lack of support for the cylinder. The only think holding it to the bucket lid was the glue, and that joint gets stressed alot when moving it around and tugging on the hoses. I was planning on installing some bracing to take the stress off the joint, but the joint separated before I had the chance to. No real damage was done, as the sheet metal simply pulled away from the adhesive. I was actually surprised how well it held up considering I didn't rough the steel up at all.

This weekend I fixed it with some scrap wood I had around. It feels solid as a rock now, and I'll be testing it out (along with my new shop-vac) tonight to see how well it handles blast cabinet duty. I'll post pics of the bracing/supports later tonight.

[cptomes]

There was a 3" hole with a stamped metal grille on it in the back of my blast cabinet. I cut a hole for a shop-vac adapter fitting I got from Sears in the upper right front edge and connect my vac when I'm blasting. I get the powdery stuff that doesn't blast well any more in the vac. It's still pretty dense, though. I'm tempted to make a mini-cyclone separator (about 6" diameter and 10" tall) and have it right inside the cabinet. Put a spring-loaded trap bottom on it. Vacuum would hold it shut until it filled enough to drop when the vacuum shuts off. That would keep the blast media in the blast cabinet and reduce the amount going into my vacuum.

[black300zx]

Originally Posted by cptomes

There was a 3" hole with a stamped metal grille on it in the back of my blast cabinet. I cut a hole for a shop-vac adapter fitting I got from Sears in the upper right front edge and connect my vac when I'm blasting. I get the powdery stuff that doesn't blast well any more in the vac. It's still pretty dense, though. I'm tempted to make a mini-cyclone separator (about 6" diameter and 10" tall) and have it right inside the cabinet. Put a spring-loaded trap bottom on it. Vacuum would hold it shut until it filled enough to drop when the vacuum shuts off. That would keep the blast media in the blast cabinet and reduce the amount going into my vacuum.

Same here. There's a rectangular boxed baffle running vertically up the rear right side of the cabinet (internally) which then leads to a similar ~3" diameter hole which had a snap in plug. I cut a hole in that plug and installed a connectors to it for the hose (which you can see coming out the bottom of the cabinet).

Next project is to make some nicer clamps for the lid so that I can ditch the bar clamps.

The separator seemed to work ok for the bast cabinet. The bucket wasn't empty, so it was hard to judge how much actually was collected. The shop vac filter was still getting a coating of dust (but still much better than before), so I just ran the vac filterless which seemed to work well.

[black300zx]

As I was cleaning out the loft storage area in our garage this afternoon, I stumbled across the heater/AC assembly out of a 300zx parts car that I bought a few years back. I was setting the three sections of it aside when I glanced at the blower assembly and thought "Hey - that might make a **** good blower motor for a separator!".





I hooked the motor up to a 12v battery charger, and without any ducting attached, it seems like it moves a good amount of air, but I have worries that it won't actually generate enough pressure head to get a useable flow when it has to breath through several feet of 2.5" tubing. I'll have to hack up the housing a bit and make an adaptor plate to allow me to test it out to see if it's worthy of a project. If nothing else, I might be able to use the scroll housing as a basis for a DIY blower.

[black300zx]

I spend a few minutes hacking up the housing this afternoon, and it looks like it should be pretty easy to mount to a cyclone body.



To test out the airflow with some resistance on the intake side, I cut a hole in a scrap of MDF to hold a 2.5" hose coupler, and hooked the hose up to it.


I also hooked it up again to the charger so that I could figure out which terminals were positive and negative. Turns out that yesterday I had the polarity reversed, and the impeller was spinning backwards. When hooked up correctly, this thing moves some serious air. It probably flows at least twice the CFM of my shop vac. Standing about 2 feet back from the exhaust side of the scroll, the whole front of my shirt was pinned to my body. I'll definitely be playing around with hooking it up to my current cyclone, and it the results are positive, I'll be building a new cyclone or possibly modifying my current one.