02/10/21 Revised! I have some good and bad news. The good news is after twenty one years being tethered to a supplemental oxygen line my lungs have finally recovered enough that I no longer need the supplemental oxygen. The bad news is my health has continued to worsen to the point my doctors called time and required me to fully retire. I will no longer be working near full time to keep up these web pages and answer email questions about dust collection. I will miss this and all the wonderful people I have met. All will hopefully soon be turned over to others to maintain. Meanwhile, I will continue to do dust collection presentations both in person and on Zoom.
07/09/20 Revised! Amazon.com stopped paying commissions on the few sales made from this site and Google dropped commissions roughly twenty-fold. I was very fortunate that a friend who owned an ISP really liked what this site did, so he hosted this sited and provided me with a free email account. He sold that business including all equipment but as part of the sales agreement my account and email stayed free to me. That meant I really did not have to cover much more than my high-speed Internet connection and computer equipment. Then the new ISP sold again and the new owners declined to allow me free Internet or email. Their costs were small, but through a comedy of errors going from a Windows based server to Unix, everything became case sensitive requiring me to change every one of the 122 pages associated with this site. Worse, the new server did not support Cold Fusion, so all of my includes did not work. They were kind enough to move all to PHP and use a program to find all links, but they did not turn all links to lower case. Additionally, there was a big problem with my email that ended up with most of my incoming email it going to a spam filter that trapped but did not forward or make it available to me. On July 6th I woke up to 954 emails, many of them telling me that my pages no longer worked. Hopefully all is repaired and working again. Please send me an email if you find anything not working.
08/12/14 Impeller Special! When Clear Vue closed for a short while my son went back into making kit computers. Our blower template made blower housings that were too small for the 16" impellers, so I engineered a special 15.5" impeller that my machinist, Inchs Machinery in Loomis, CA (916) 652-0628 built and sold directly. These have the advantage of fitting in the existing 15" blower housings with only tiny modifications to the hole that lets the blower housing slip over the mounted motor and impeller. Anyhow, these move the same air as the 16" diameter impellers which is as much air as you can move without putting your 5 hp motor at risk. They are really great well built impellers made of heavy steel built like tanks and use the best compression arbors. They are ideal to upgrade your existing 15" impeller or to use in place of the 16" impellers. I was talking with my machinist about my new cyclone project today (8/12/14) and saw he had a pile of these 15.5" impellers sitting waiting for final balancing and powder coating. They would like to clear these out and are making them available for $250 each. When the pile is gone, I don't know if they will make any more, so move quickly if you want one.
08/27/13 These pages have been under revision for quite a while and updated pages with the new menus started going up today.
Bushey Enterprises continues to make and enhance the Clear Vue Cyclone products. In just a short while their efforts coupled with word of mouth as to how much better these cyclones work has pushed them back into one of the top makers of small shop cyclones!
07/21/11 After many requests, I developed a quick blog that hits the high points of these pages. Take a look at Dust Collection Basics Blog.
09/10/07 After considerable work with much help from Steve Hall, these web pages were reformatted to load far faster and be easier to follow.
09/9/07 "Bill, I previously wrote you about the ongoing fight between the two largest advertisers of small shop cyclones. That fight got pretty ugly last year with XXX (the top magazine rated cyclone vendor) saying YYY (the largest small shop import equipment seller) flagrantly copied their design. What do you know of this controversy, and do you recommend the cyclones or dust collectors from any of these vendors?" I was permanently expelled from the Woodnet Internet Woodworking forum earlier this year for answering exactly this same question. What I said then still applies today. This whole mess makes me laugh and I strongly dislike the behavior of both of these vendors. I also cannot recommend either.
The copycat vendor has a long history of stealing other commercial tool designs, gets these made in bulk in China, then undercuts those they stole from plus uses international legal loopholes to evade patent and copyright violations. The only surprise in seeing them do the same again is how long it took them to start selling their indoor cyclone copies because their outdoor cyclones worked dismally.
The complaining vendor who whined so loudly with extremely negative forum posts and negative web page write ups on their web pages is a fraud who built their business on a fear of fine dust campaign while delivering a cyclone that worked so poorly it actually made the dust problems far worse than just working with an open door and fan in the doorway. I know because this vendor's cyclone and ducting system left my shop with a bad false sense of security. My shop looked clean, but that cyclone I installed to protect my health ended up landing me in the hospital and costing over half my lung function. Frankly, they are the ones that inspired me to come up with a better cyclone design and write these web pages.
In terms of history this whining vendor has a long history of problems. In the nineties the Internet forums clearly showed they stole their cyclone design and it worked terribly. There are many very skilled people from all walks of life who enjoy woodworking. Researchers showed this vendor's patented cyclone design was actually the design published in 1962 by the New York Department of Public Works modified to fit under an 8' ceiling with a small cartridge filter shoved into the cyclone outlet. Almost every owner of this cyclone had serious problems with the filter constantly clogging, the ducting clogging, and the airflow being terrible. Expert air engineers and scientists showed this vendor used a tiny blower that barely had enough power to drive the air spinning inside the cyclone leaving almost no airflow left to provide good collection. Worse, this vendor understood nothing about air engineering and designed their ducting systems with down drops as small as 1" feeding 7" and 8" mains. With all the other blast gates closed as the vendor recommended, these tiny down drops killed the airflow in the mains causing them to build up huge piles of dust. These experts also found this cyclone constantly plugged when doing heavy planning and when doing sanding it sucked the dust out of the dust bin into the filter. This vendor's president became a frequent poster on the various woodworking forums and denied everything strongly. Worse, with most of the forums financed by vendor advertizing, he not only got these very strong negative posts about his products deleted, he managed to get almost every scientist and engineer who spoke up permanently banned from all the larger forums.
Nothing much has changed since. This vendor now sells a cyclone that starts with that 1962 cyclone copy and then modifies it with almost every change I shared out in 2000 to improve the dismal airflow of that cyclone design. The performance of these cyclones is terrible. One of the most respected small shop woodworking magazines commissioned a test of all the major small shop cyclones in 2007. That testing found exactly the same results as did the woodworker scientists who performed independent testing. Every small shop cyclone except for one provided little better separation than a typical $25 trash can separator lid and filtering was dismal freely passing the fine dust that most woodworkers buy these fine filters to avoid. The one exception was the cyclone I designed and was sold by Clear Vue Cyclones provided far better separation without a filter than any other small shop cyclone with a new filter. With the recommended filters, this was the only cyclone that immediately provided both the needed airflow and fine dust removal. This vendor not only used their advertizing clout to kill that article before it was published, they now take a couple of tests totally out of context to "prove" their cyclone performs far better than mine. Worse, this vendor on their web pages has now selectively assembled pieces of various emails that I sent trying to help that vendor and turned what I said into my being one of their largest supporters when I am the opposite.
The reality is that vendor suckered me into installing their most expensive system that was a complete fraud. It looked beautiful and did a great job leaving my shop looking clean. What I did not realize until I landed in the hospital that their cyclone provided no fine airborne dust separation and the upgraded finer filter that I bought at their recommendation was a sieve that freely passed the finest unhealthiest dust. Air quality testing three months after I had to stop woodworking showed my home still badly contaminated. My garage-based shop tested clean until we turned on my cyclone. Without doing any woodworking, just turning on that cyclone raised the airborne dust levels to dangerously unhealthy. Anyhow, my bottom line continues to be trying to educate other woodworkers, so you don't also get blindsided by all the advertising hype put out by our small shop dust collector and cyclone vendors.
03/20/06 Knowing my health has pushed me out of the evaluation business, I began working with magazine editors to improve their evaluations. The first of those efforts showed in the April 2006 issue #183 of Fine Woodworking with Michael Standish's article on "Portable Dust Collectors". Michael did an excellent job explaining the difference between the high airflows needed for good fine dust collection and the modest airflows required to do "chip collection" meaning picking up the same dust we would otherwise sweep up with a broom. Mr. Standish also made a very important point in his article, the first of which I have yet seen in any of our woodworking magazines. Almost any dust collector or cyclone that moves at least 350 CFM with a fine filter will leave a clean looking shop while building up dangerously high amounts of fine invisible dust known to do the most damage to our health.
Michael's testing showed that only the two best 1.5 hp portable dust collectors barely moved enough air to meet OSHA air quality standards which leaves dangerously high amounts of fine airborne dust. Frankly I am a little disappointed that this article did not simply state that we need at least a 3 hp motor turning not less than a 14" diameter impeller for a dust collector or at least 5 hp motor turning not less than a 15" diameter impeller with a cyclone to move ample air to meet the higher EPA, medical and European recommended standards that I think all small shop owners should maintain. The EPA finally agreed and now this is the new U.S. standard which has been adopted throughout most of the world. I also would have liked to see this article deal more with current filter practices. The testing was done using a good filter on all the different units. Unfortunately, the article was not clear to me that there is a serious problem with almost all of today's small shop dust collector and cyclone filters. Our vendors keep selling filters rated after they have built up such a large cake of dust that they will barely pass air. Until that cake builds, these finer filters simply pull off all of the visible dust allowing the most dangerous invisible dust to blow right through then build up in our shops. I know from personal experience this is terrible news. This false sense of security from a clean looking shop allowed the dust in my shop to build to very high levels that kept getting launched airborne every time I worked in my shop. Worse, my use of many toxic and allergy producing woods like cocobolo, rosewood, walnut, red cedar, etc. made the invisible dust in my shop dangerously unhealthy. I suffered a violent allergic reaction that so shut down my airways my heart did not get enough oxygen. The resulting repeated bouts of pneumonia cost me over half my respiratory function and left me dependent on supplemental oxygen for life. Frankly, this vendor nonsense which creates a false sense of security is what motivated me to go to all the work to write and maintain these pages giving the information so others can avoid similar problems.The really good news is after twenty years of having to have supplemental oxygen, in 2020 my lungs had recovered enough that I no longer need supplemental oxygen.
11/15/05 Although many vendors disliked my Cyclone Comparison web page after it was installed in 2001, I kept that page current in spite of the high cost and time demands to do testing because no other sources provided accurate fine dust comparisons. Many new cyclones announced in 2004 and 2005 showed us as more copies of the same ineffective units that could only be made better by adding the neutral vane and other changes from my Cyclone Mods web pages, plus upgrading to a 3+ hp motor with bigger blower, tossing the filters, and blowing the air outside or using huge filters far bigger than any supply. I saw no change in physics that would make these new units move a real 800 CFM against typical shop resistance levels, but every vendor claimed new magic. Regardless, no longer able to do the testing and a couple of vendors complaining fairly that my page rated their older models, I decided to pull down my evaluations, rewrite that page, and work with the magazines to improve their testing.
10/24/05 See Sugi's excellent solution to knowing when to empty the dust bin on his cyclone by clicking on the "Dust Level Sensor" in projects menu column.
07/09/05 "Bill, would you please give me your two cents on the new cyclones being sold? I want to buy one, don't have the time or patience to build, and want to make a good choice." Take a close look at my updated DC & Cyclone Review Pages. I think the updated information there will give you a good idea of what you need to consider so you can make a more informed decision on these and any other new cyclones that become available. I strongly recommend building my design from my web pages or buying a kit from my son. I think these other designs are only viable if you are running them with a 5 HP motor and venting outside without filters.
06/15/05 Note the site now has many new upgrades and rewritten pages to make it easier to follow and faster to load.
05/16/05 Having been forced to retire last year with health issues my income dropped significantly leaving me scrambling to subsidize this site. I tried selling plans on eBay, providing advertising on this site, licensing my cyclone and blower designs for others to build, and even asking for donations, but nothing generated enough money. I'm now using a few general paid ads to help cover expenses. Please support these firms with your patronage.
03/12/05 A couple of Texan woodworkers just wrote saying, "Bill, we owe you big time! Two years ago my buddy and I built a CNC router and began making MDF cabinet doors in my garage shop. Our business took off and did so well we hired two employees. Soon, our employees, my family, my partner, and I stayed sick with coughs and respiratory infections. My shop and home was filled with fine dust. In desperation we got on the Internet, found your site and built our cyclone and ducting from your plans it in early 2003 to just take care of the dusty CNC machine. Although everything immediately got clean, it took months before everyone finally got well. Our shop is now clean as a whistle. Better yet, in spite of filling a couple of 55-gallon barrels of dust every week our filters are still clean. Since putting in your cyclone less than a cup of dust has built up in that pair of cartridge filters. Thank you and I pray for your improved health. Here is a check as our thank you and hope you will keep up the good work!"
03/14/05 "Bill, I see Grizzly is now advertising your incredible cyclone that I built back in 2001. I hope they paid you fairly for your work, but suspect from their lack of giving you any credit on their ads that you probably got nothing. I wanted to let you know that what you have done to educate woodworkers on the dangers of fine dust and share designs that really work is very special. Your work is helping to protect the health of many." Thank you for the kind words. I did try to help Grizzly and that unit looks somewhat like mine, it is actually a near exact copy of another more popular cyclone vendor who has long stolen my information from these web pages that they rewrite and put on their pages, keeps stealing my cyclone design one piece at a time without permission or giving me any credit, and keeps putting out a dismally poor cyclones that do such a poor job of separation and filtering, I strongly recommend against their purchase.
11/01/04 Sadly, after carrying Clarke F. Echols and his Clean Shop Air through sixteen months of excuses, broken promises, poor quality work, and failure to pay a single penny of what he promised and owes, I took away my support for him to make or sell my cyclone or blower designs.
10/15/04 Wynn Environmental has developed a great cartridge filter to make existing dust collectors far safer, (Click here for more information).
09/21/04 Ed Morgano has some incredible pictures of my cyclone design he made in clear plastic running. See the Clear Vue Cyclones Videos pages to see more.
Major Revision Links
New Pages and menu starting to go up! Updated 8/27/13
Dust collection Blog started as a quick overview! Updated 6/27/11
Sugi's Dust Level Sensor to tell when dust bin is full!
Revised downdraft table plans and instructions for building your own.
Updated Home and Introduction
Updated Medical Risks and Doc's Orders
Latest Cyclone Design and Spreadsheet in Metric.
Updated Ducting Information
Updated Plans and Building Instructions
Measurement Site provides details on how to test and measure system performance!
Revised Dust Collection Basics for those just getting started
Revised Equipment Information
Deciding Needs provides the detail for those who want to do the calculations and work to set up their own dust collections systems from scratch.
Building a Budget Blower with latest plan improvements
Pictures... Here's a quick way to upgrade your existing DC to a cartridge!
Stephen Silca picture tour of building his cyclone and budget blower from my plans with cost analysis! Well done Stephen
Pictures... Al Hallaman shows how to do dust collection for a TS sled. Thanks Al!
More Pictures... Steve Cater solves a 4" ducting problem and shows off his cyclone! Thanks Steve!
Check the Cyclone Plan Page for updates and new suppliers
Picture Tour of Dale Critchlow's building one of these cyclones. Thanks Dale!
Vendor Information - Hood designs, CFM Requirements & Static Pressure Calculator
Static Calculator FAQ
Modifying an existing cyclone with FAQ
Tips and Tricks on Working with PVC
Long Island National Institute of Heath News Release - Wood Dust a Carcinogen
The reader assumes all responsibility and liability associated with the hazards of woodworking and dust collection. Dust collection when improperly built, implemented, used, or maintained may cause serious injury or even death, so USE THIS INFORMATION AT YOUR OWN RISK! The author has no control over how a reader will act as a result of obtaining information from these pages. Your actions are your responsibility, VERIFY and CHECK information out before proceeding, and don't attempt anything without the required skills. The author shall not be responsible for any errors or omissions that may be present on these pages. Accordingly, the author shall assume no liability for any action or inaction of a reader.
The drawings, procedures and words shared on these pages are as in use by the author and shared for information only. No claims are expressed or implied as to the safety, usefulness, or accuracy of this information. Neither the author nor any other references or links on these pages will accept any liability for any damages or injury caused to people or property from use of this information or from any associated links.
These pages are directed toward a hobbyist and small shop woodworker audience and are not intended for application in a commercial, institutional, or industrial setting. Commercial woodshops are generally governed by a complex set of worker safety regulations, such as those mandated by OSHA. Satisfying the compliance of such regulations is beyond the scope of these web pages. HIRE A PROFESSIONAL ENGINEER to design, specify, test, and certify performance of any dust collection system if you have a commercial or an industrial application, allergies, other medical problems, people working for you, a large shop, work with hazardous materials, or are subject to regulatory oversight.
Unless you as a woodworker provide appropriate fine dust protections, most small shop owners put your health, the health of those close to you, and even the health of your pets at risk. Unfortunately, particle testing by the author and hundreds of others all across the country shows those who vent inside even with very clean looking shops invariably have huge build ups of invisible dust. Government testing shows on average just one hour inside a small shop that vents its dust collection inside results in more fine dust exposure than large facility commercial workers receive in months of full-time work. The difference is almost all large commercial facilities vent their dust collection systems outside, so they rarely build up the fine invisible fugitive dust that escapes collection. Even with venting outside, the peer reviewed medical research shows the more fine dust we take in the greater the short- and long-term health damage and this research also shows even with their much lower exposures almost all large facility woodworkers develop serious dust triggered health problems and significant loss of respiratory capacity. This much higher exposure information should terrify small shop and hobbyist woodworkers because of our much higher exposures. Respiratory doctors who have read these pages share small shop woodworkers and their family members often have the worst respiratory problems. Please take the time to protect yourself and those close to you.
Errors and Updates
I have made every effort to make and keep this site accurate, the continued rapid evolution of dust collection and my own lack of knowledge may make some of this information dated and even wrong. Any errors are mine, not the many who have contributed. I appreciate people bringing concerns to my attention, and I try to repair problems as quickly as possible. Likewise, I often update these pages with new information as a result of feedback from experts and fellow woodworkers. Please make sure you regularly refresh your browser to get the most current information! Also, please understand there is a wide variation in skills and we are dealing with equipment that can be dangerous, so be careful in whatever you choose to do. Please enjoy and work in a healthy safe shop that you keep that way.
© Copyright 2000-2022 - William F. Pentz. All rights reserved. No other part of this material may be reproduced or utilized in any form or by any means, including electronic or mechanical. Any commercial use, sale of my designs, sale of products created from my designs, or any public display of the information shared on these web pages through other means including the Internet is strictly prohibited without my advanced written permission.
I've spent many years and thousands of dollars carefully designing, testing and improving a very efficient cyclone appropriate for owners of small shops. My cyclone was designed with the most efficient airflow internally of any available small shop cyclone which lets us use a much smaller blower to move the air that really good fine dust collection requires. Airborne dust ruins our lungs and also clogs and ruins fine filters which is why commercial shops must replace their fine filters every three months of full time use. My cyclone provides over five times better airborne dust separation than its nearest competitor. As a result this is the only cyclone design that lets you use the expensive fine filters we need to protect our health without having to replace filters every three months of full time use like commercial shops must do. Two patent attorneys assured me that I can patent my efforts due to my many unique enhancements over traditional cyclone designs. Only Clear Vue Cyclones and my son have my support and authorization to make and sell my designs. I share this design so small shop owners can avoid respiratory problems similar to mine. The patent laws let only individuals make these cyclones for their own use. I do not approve or support any person or firm who makes these units for sale without my written permission.
Copyright and Patent Discussion
Please do not steal my efforts! Folks, I spent years and many thousands of dollars to develop these copyrighted web pages that I share on the Internet to help others protect their health and the health of those close to them. By copyright law and my intent, woodworkers may make paper copies and use my efforts and designs to make cyclones, blowers, and implement other dust collection protections only for their own personal use.
So many people linked to my site without permission putting my charts, graphs, pictures, etc. on various forums and personal web pages that my ISP account received over 3,000,000 daily file accesses. This theft pushed my account from a personal web page to the largest and most expensive commercial account on my ISP. To stop this, my ISP did some blocking and had me change URLs to BillPentz.com. All are welcome to, and even encouraged to provide the following link to my main Cyclone and Dust Collection Research page and to my Dust Collection Basics page. Please do not directly link to anything else as that quickly kills my ability to afford these new pages.
These pages continue to change, grow, and get refined as my knowledge improves. Unfortunately, a number of people share copies of my pages on their own web pages without permission. Most simply copy my pages then change the advertising and even PayPal links so they get paid instead of me. The shared pages obviously do not stay current, but pose a more serious problem. In a few instances vendors and individuals change my information to give bad or inflammatory advice and advice that can be dangerous or even deadly. Please make sure you read from Cyclone and Dust Collection Research pages instead of an untrustworthy link.
Roughly a quarter of my dust collection emails come from people confused because others keep giving partial answers and just plain bad advice that they say came from me. Most of this comes from a very few latecomers I helped who now claim credit for work done years before they ever became involved. Sadly, the loudest of these cannot and will not either read or take the time to learn what they are talking about, so they continue to cause lots of confusion. Please just refer people to my specific web pages rather than paraphrase or quote me out of context.
Finally, too many people and firms now illegally sell my work without my permission or paying me anything. By stealing one piece at a time every small shop vendor except one now sells cyclones that are more my design than their own and most sell the cartridge type dust collectors that I innovated. The worst of these small shop vendors is rated by many magazines as the best cyclone maker, but in truth they are now using my inlet design, my outlet sizing, my revised cone, my air ramp, my dust chute sizing, my blower housing, my impeller design and sizing, my filter stack, my cleanout design, my ducting designs, and considerable flagrant theft from my web pages including my airflow tables, resistance calculations, test results, on and on. Worse this same vendor continues to use their legal staff to force me to leave off the objective testing that shows even with all their thefts that their cyclones separate little better than cheap trashcan separator lids and their filters are so wide open use of their equipment will push the invisible unhealthiest airborne particle counts to dangerous. Many small firms have gone into business building cyclones and cyclone kits based on my designs, then expect me to field their customer questions without ever paying me a penny. Multiple You Tube production firms are building their businesses by referring to me and my web pages without my permission and sharing just plain bad information. There are multiple firms that flagrantly stole and now either sell or use for their own marketing many of the tables, spreadsheets, and other information from my pages including my toxicity table, static calculator, cyclone efficiency calculator, and even my ducting designs. Multiple advertising services now steal copies of my static calculator spreadsheet and my scalable cyclone spreadsheet that they let people use for free in order to display lots of paid ads. Two get rich quick spammers sell CDs with full sized drawings of my plans via email and on eBay. Only Clear Vue Cyclones and my son can legally sell my efforts. Please DO NOT BUY, SUPPORT, OR RECOMMEND ANYONE ELSE and LET THESE LOW LIFES KNOW HOW LITTLE WE APPRECIATE THEIR THEFTS. Let me know and directly complain to eBay if you see any of my plans offered on eBay by anyone other than electricsurf (my eBay name). Please also let me know of any web pages you find with copies of my work and I will contact the offending Internet Service Provider to remove that material.
For years I used a "free" but misleading visitor counter that only increments with certain types of page visits. My ISP tracks all access to every page, picture, and file on my web pages. Their records showed over 38,000,000 unique visitors checked out this site from February 2000 when I opened these pages through May 2010 when the ISP was sold. The new ISP did not record visitor counts, but instead recorded with each spending an average of 13 minutes viewing the material. Following the rewrite in August 2003 the visitor count climbed to over 3,000,000 page hits a day with a unique visitor count of over 18,000 daily. That was good news except it pushed my account to the most heavily used and expensive business account. To again be affordable, I had to change the URL name in early July 2004 to break the many unauthorized links. That worked but dropped my pages to far down on the search engines. They rapidly came back, but so did the unauthorized links. Again in 2012 more changes killed many of these links but also pushed these pages down on the search engines. Another rewrite started in 2020, plus renaming all the pages to PHP files from CFM has dropped readership considerably. Regardless, since 2000 this remains the most heavily visited dust collection information site on the Internet. It is also mandatory reading for many government, industrial, and college organizations.
Thanks for dropping by!