Stop adding cyclones to your under-powered dust collector!

If you're a proud owner of a single-stage dust collector in your workshop, or plan to buy one, and are considering the idea of outfitting it with a cyclone collection system, then wait. Watch this video first before making that decision. It's not a short video but I want to provide my experience with cyclone collection/separation solutions, in an unrehearsed, and straight from the heart, candid message explaining the trials and the potential risks in using them.

This video is focused toward small shops, moonlighters, and weekend woodworkers using basic dust collectors that aren't designed, nor powered enough, for a cyclone separator. Two-Stage cyclone solutions serve perfectly well in larger shops when the system is engineered and sold as a complete solution.

NOTE: I mistakenly described my manifold setup. It consists of four "Y" connectors, not "T" connectors and has 2 long-throw 90 degree connectors because 45 degree connector pairs would not fit the tight space below the workbench area it is running through.

[John-NeverStopLearning]

I was considering making an adapter from the collector to a city compost bin. Now I am not so sure because of the fire hazard. Thank you 😊

[mattsousa]

The other advantage I've found with a 2 stage setup, is that the impeller and motor life increase substantially as your not pulling those large chips through the impeller as they fall to the bottom of the drum and the fine dust gets pulled through the impeller into the bag.

[baronc]

Thank you for this. Makes total sense. I like having a bucket cyclone on my shop vac cuz dealing with the heavy head on the vac makes dumping it out a pain. But on a central dust collection system where the heavy load is supported, just makes sense the way you have it

[thehickorylanewoodshed]

Thanks! I just got my Harbor Freight system and added the canister filter to it and was trying to figure out the best way to add a barrel to this but, now that I have seen this and with your experience. I will just keep the bag in place. Thanks again.

[petec]

My experience with separators is air flow. Higher velocity will separate more dust. I had this experience with a small separator. When hooked to my sander, air flow was so restricted by the presence of the working piece to the face of the sander that air flow was minimal Beyond the separator is the filter, and yes, it clogs up with very fine dust. And yes, it has to be cleaned out periodically. Armed with this self revelation I decided to add a second port to my small dust collection (not to be confused with my large collector). This second port can be opened then blocked with a smaller pipe which allows air to infiltrate the system but still drawing sanding dust away from the work surface. The result has been greatly reduced amount of time I have to spend cleaning out the final filter and more fine dust making its way into the separator. Air flow is the key. Ultra low air flow means very slow moving dust and much less cyclonic action, which results in failure to separate the fine dust. Again, air flow is the key to good dust separation. Prior to upgrading my large dust collector I removed two coffee cans worth of ultra fine dust from the cloth filter bag. Cleaning dust collectors IS a fact of life. Unless you have your exhaust blowing outside the shop. But then in the winter you're blowing all your heat outside. In summer you're blowing your cool air out of the shop. Exterior exhaust would only be plausible when the weather outside is as good as you want inside. Here, where I live, that's rare. Summers are way hot and winters are way cold. Spring and Fall seem to last just a few weeks each.

One last comment directed at this video - way too much talking. I skipped through much of it before just stopping it and commenting. Nice effort and good information, but the presentation is way too long to hold much interest. At least my interest. Don't know about others.

[nidavis]

In my two-stage collector used for the large CNC, the type of material I am cutting determines which side needs changed the most often. When cutting MDF, the container on the filter side needs constant emptying while the separator container stays mostly empty. When cutting plywood or non-composites, as well as plastics, the cyclone side fills up much faster. Running constant 5x10 MDF sheets requires emptying the dust from the filter side at least once a day if not more.

[duperdude]

After watching this video I got an idea. You have your dust collector and you also have your dust extractor like these for small tools as you know large system is not that great for hand tool dust collecting applications. So, I bought a Kirby vacuum cleaner motor head which has an impeller that is separated from the motor, which has a separate assembly to get cooled. The impeller sucks the dust and within few inches exhausts it to a bag via 3 inch pipe. I’ve removed the bag and connected the three inch hose to a 4 inch hose to my large shop three stage dust extractor with cyclonic action. This way I have one place for all the dust from the small and large tools, none of the filter expense of expensive small systems like festool and other, takes very little space and it’s in-line install setup for under 100 bucks. Awesome video as always very informative. Thank you.

[johnsjarboe]

In my opinion cyclone separators are essential to prevent unnecessary damage to the blower impeller. When I added one to my system, I cut a rectangular viewport in my can and sealed it back with plexiglass and silicone caulk. That way I can see how full the can is & any potential fire issues.

[gjforeman]

You mention the risk of hitting a nail and throwing sparks into your cyclone or trash can, but I've heard the same argument about your single stage collector, where a stray bit of metal sucked up by your system hitting that massive impeller, which is the first thing EVERYTHING you suck up comes in contact with. I have the same HF single-stage unit you do. When that bag gets anywhere near halfway full, it is a hugely dusty struggle to remove it and shlep it to the trash can. I am planning to make my HF collector a 2 stage system in the near future, probably with a large Dust Deputy cyclone. Thanks for your honest opinion.

[nospamallowed]

Here is a crazy thought:

There are some vacuums that use a water trap to avoid blasting dust back out of the exhaust.

As a "cheap solution” to fine particles, If you are already using a cyclone to capture the larger dust, why not simply send the exhaust from your vacuum through a pipe to the bottom of a bucket of water? With a lid perhaps… to avoid water drops from the bubbles spilling out.

[ericma]

It s a very good video with lots of information. However, from my learning about the dust collection, cyclone is a device to separate the dust or larger chip before the blower. If in case a larger or harder piece goes to the system, it hit the fan blade and eventually break or bend the blade. I think it is one of the reason why people add cyclone before the canister filter. Am I right?

[edraisner]

The separators of any type are also in place to keep your existing canister type collectors operating at peek efficiency. As the beg fills- the CFM is drastically reduced. Separating the large pieces, reduces this issue. And I would agree that the “micro dust” passes through the separator- that’s when a quality filter bag or canister type pleated filter is important.

[pcrengnr]

Hey, Frankly thx for the insight and taking the time to make this video. I agree on some points and disagree on some points. From what I have seen cyclone systems are not engineered they are just thrown together. This leads to mismatched systems in many ways. None of the DIY cyclones state what the optimal flow rate is and that is a disservice to the buyer.

Cyclones are designed to operate over a range of air flow. Too much flow and or too little flow and they don't work. When you look inside a Dyson vacuum you will find a HEPA filter. That filter is there to filter the air when the system is starting up or shutting down when the airflow is not optimal for the cyclones to operate.

As for suction reduction ALL filtering systems impose a restriction to flow, period. It's just a matter of how much and can the system tolerate the reduced flow.

I live near a bunch of defunct furniture manufacturing plants and they ALL have cyclonic separators either on the roof or near the building. It is quite telling that they are all outside. If these manufacturers didn't have clean air in the building(s) then OSHA would force them to clean up the air if they wanted to continue to operate. Hooray for OSHA which typically gets a black eye for all they do to protect the worker from corp greed.

Frankly, you have a great point about a hot ember. Mitigating that problem seems like it would be its own study. Maybe flame detectors, metal cyclones etc.

I like the bag idea and it makes a lot of sense. The bag requires to be in a stiff container if negative pressure is present or no container if positive pressure is present.

Back to the Dyson vacuum. They use a two stage cyclonic system. The first stage removes stuff like small animals, matchbox toys and other big things. The final stage uses an array of parallel small cyclones. When you dump the filter canister you can see the super fine dust is trapped in the center section and the big stuff is trapped in the outer section. And don't forget the HEPA filter for startup and shutdown. Always dump the canister outside not in your home.

If a properly designed cyclonic system is good enough for a furniture manufacturer then it's good enough for my shop. Again, properly designed not just thrown together.
A white paper is on the internet that shows how to design a cyclone. That and a spreadsheet and you're on your way to a successful design. It all centers around particle size you are trying to filter and flow rates.


There are formulas, no calculus and a lot of text for guidance.

In summary:
You need to have a matched system for the fan/blower that you are using. Be it a filer or cyclonic system.
Filters are still needed.
A two stage system is best. A stage for big stuff and a stage for super fine dust.
Don't expose the contents of the collection device bag, bin or box to the workshop area.
Be mindful of hot embers and their mitigation.

Frankly thx for making this video and sharing.

[rickrogers]

Agree on you tube sales pitches. I gave up on several of the lawn care channels. It was like watching home shopping network at times. Nice video.

[kenzaleski]

I believe that a cyclone in a properly designed system can work very very well. I service industrial printers for a living. One of the models I take care of use a cyclone for all cleaning in the machine, for toner and paper dust, both of which are much finer (sub micron) than any sawdust that I'm aware of. The air filter in these is a .5 micron rating, these filters last for usually about 5 million prints. If that much toner and paper dust were going past the cyclone that filter would plug up instantly, ( they are smaller than a shoebox!), even after a month of running 8 to 24hrs a day that filter is clean as a whip. The cfm must be matched to the pipe and overall system layout to be effective. Yes, cyclone separators do induce loss, but this should be planned for, then it's not an issue. Great video, luv the content.

[chrismaxa]

How do you feel about impeller upsizeing/upgrade?

[justadddiesel]

Watch Under Dunn, he makes and tested a system with a cyclone. It works better than his old bag system

[woodshopnerdery]

100% share your opinions, but I do believe it is a matter of personal preference also.

I had a Dust Deputy (small cyclone) in the past in line with my ShopVac which was a big help because it prevented the pleated filter from clogging up. In this case, the cyclone INCREASED suction and air flow because it kept the filter clean. It also paid for itself in replacement filters.

For a true bag-bottom/filter-top dust collector, these already have chip separation built in, that's why the heavy stuff falls into the bottom bag. When I upgraded to a true dust collector I got rid of the Dust Deputy. My dust collector rolls around from machine to machine and there is no need for duct-work. It would be a real pain to move a cyclone or baffle system around with it. The impeller is steel and I have no worries about the chips hitting the internal parts.

However, I do agree with the folks pointing out the planer/jointer chips clogging the inlet from time to time. I suppose there is no "Goldie Locks" system.

[kellyanderson]

I've really benefitted from my cyclone. It's so much easier to empty than the bags. It takes two people to easily change the bag. The cyclone bin is easy for one person to empty. Of course, I'm emptying it every 15 minutes when using my big sander.

[John-NeverStopLearning]

I have an old high power Craftsman wet/dry shop vac. I put a cyclone on it. Return it. (Cyclone) I lost about 50% power. And the vacuum was pulling the dust straight from inlet to outlet. Yes the cyclone I had was sized for the.CFM of the vacuum and the hose was a match in size.