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View Full Version : VERY LONG Cyclone Separator Review (dc to cyclone conversion)



Andy Howard
08-03-2005, 1:45 AM
I mostly just lurk and soak up the knowledge, I figured I would finally contribute to this great forum in hopes that someone will find this useful.

Ever since I started woodworking I have hated the big dust mess and I am very cautious with my lungs. I have already had a lung operation (unrelated to woodworking) and I can tell you from experience that it hurts like living hell. Literally!
<O:p
So, I usually do all my woodworking wearing a respirator, but still wanted to cleanup and improve my dust collection. Here is my progression to a “homemade” cyclone.
<O:p
I started out with a shop-vac. Not very good. Then I got the HF 2hp dust collector that everyone talks of. Right away I also ordered a wynn environmental filter for it. The filter is supposed to be 99.99% efficient at 0.5 microns. This was a while ago, before they made a special kit, and the filter is a bit different than what they currently send with their kit. It worked well, but lost suction quickly due to buildup of dust (sawdust) in the filter. I began looking at cyclones, but couldn’t bring myself to scrap what I already had invested (maybe $225 with filter) and buy a dust gorilla or a grizzly cyclone. I read up on Pentz page, and read some more. I then came across a cyclone separator on ebay for $139. It looked good, and the total cost to get it shipped to me was only 159, so I took a chance and went for it. This is the cyclone from www.cycloneseparator.com (http://www.cycloneseparator.com/)
<O:p
Upon arrival of the filter I opened the box and inspected it. The cyclone is well made, and came reasonably protected. No damage I could see from transit. The unit is not painted or powder coated, but it is for a shop, and I could care less as long as it gets the dust. The seams are not ground and polished after assembly, but again I don’t really care as long as it works.
<O:p</O:p
I ordered the 7" unit, which is the larger of the two. I made a little plate to attach it to a trashcan, and used a 7"-6" and a 6" to 4" fitting to get it connected to my DC. I then used a 6" to 4" fitting to get a hose put on the thing to test it. This is not an ideal setup by any means. I fired up the DC, and started testing. I will start off by stating that my test dust was actually the dust I vacuumed out of the filter from when it was just a normal DC. It wasn’t particularly fine, or coarse, just a mixture that had clogged the filter over the past few months. I started with my DC filter clean and a brand new clear bag on the bottom. I fed quite a bit of dust in and watched to see what happened.<O:p</O:p

The cyclone in stock configuration worked well, capturing approximately 90% of all the dust. Keep in mind this was with 3 reducers and an immediate 180 degree bend in the 4” flex hose coming off the top of the cyclone to make it back down to the DC inlet. Much less than ideal!!

After all the time spent reading Pentz’s site I knew that this could be made in to a better cyclone!

So……I started moding (modifying) it!

I took the top off of the cyclone, which is pretty easy after you know what you are doing. The top piece is held in place by a bent lip of metal that comes up from the main body of the cyclone. Just pry this up straight, and you can lift the cyclone top off, which includes the outlet pipe. Make sure to put a reference mark on the top and body before you remove it so you can line it back up later!

Now that the cyclone is disassembled, there are three things to do to really bump up performance. I will list them in order of importance.

1. Using a blowtorch melt the solder around the stock inlet and remove it from the clyclone. This will leave an oblong hole in the side of the cyclone. Go to home depot, lowes, HVAC shop, or whatever you have available and buy a 2 foot section of 6” snap lock pipe. They come in this size precut in my neck of the woods. Then using the entire pipe reinstall this as the inlet pipe and neutral vane all as one unit. The internal (inside the cyclone) end of the pipe should stick half way in to the diameter of the cyclone. When you position this pipe remember to add a bit of down angle to it. I made it so the external (of the cyclone) end of the pipe (18” or so from the cyclone) is roughly level with the top of the cyclone. This will give the dust a smooth run and a downward flow in to the cyclone. You will also have to cut a small portion off of one side of the pipe on the interior of the cyclone to get it to fit and have enough clearance for the cyclone outlet (which extends down in to the body). After you get it all fit up and ready, go ahead and solder it back in place. This is best done with two people, one holding the pipe and cyclone with heavy gloves and vice grips, and the other to do the soldering. I did mine by myself, and it looks bad, did my buddies with him and it looks great.

2. Now, measure from the bottom of the cyclone to the bottom of your intake pipe inside the cyclone. You want to make the outlet pipe of the cyclone (7” pipe that sticks down the middle of the top) extend approximately 2.25 to 2.5 inches lower than the neutral vane you created. The way the cyclone comes from the manufacturer it is too long. I had to cut right at 4” off of mine. These measurements apply only to the 7” outlet 6” inlet version of the cyclone. There are two sizes, and this is the proper length for the larger one only. If this pipe is left stock it will suck too much dust from the sides of the cyclone as it starts to fall in to the cone.

3. While you got the cyclone open and easily available to the inside, go ahead and grind down the rivets that are left on the inside. I don’t know how much of a difference it makes, but it is easy to do.
<O:p
After you have all this done, go ahead and put the top back on. Get it on and bang the lip back down to hold it on. You can solder this, or just put some caulk on it to make it airtight.

You are now done with the cyclone modification. You can use it as an inline separator, or as a cyclone tower like I built. I wont go in to detail on the build of my tower, but I will mention that I increased the intake to 7” on my DC impeller.

The first pic is to give you an idea what I ended up with. This is before ducting was run. I ended up running 6” S&D PVC. I am still having to use 4” flex hose for my tool hookups for the time being since I haven’t been able to get any 6” flex hose and still need to finish my 6” blast gates.

I have to say that I am totally impressed with cyclones and their efficiency. I had about 10 gallons of dust in my trash can today when I emptied it, and in my “cleanout” there is 0.1 oz (yes I weighed it) of really fine dust after cleaning the filter with compressed air. See pic 2 for proof. My best guess is that I had at least 10 lbs of sawdust, probably more, but I didn’t weigh it, as at the time I had no intentions of doing such a write-up! I have about a cubic inch of dust from the cleanout.

If my simple math is correct (feel free to correct me if it isn’t)! That comes out to an efficiency of 99.875% when calculated by weight, and 99.96% when calculated by volume!!
<O:p</O:p
Lets say that I am way off, and I have twice the residual sawdust in my filter/cleanout, and only half the amount collected in my trash can. .2 oz and 5lbs respectively by weight, and 2 cubic inches and 5 gallons by volume. That still calculates to an efficiency of 99.75% (weight) and 99.85% (volume)!

Now, before anyone starts jumping all over me; yes I am sure that most of what is left in the filter and cleanout is the very fine dust, so the cyclone is probably much less efficient when it comes to the very small particles, but in my opinion that is what the filter is there for. The cyclone is to keep the filter from getting clogged and provide for an easier method of emptying the sawdust from the system.

I hope that I haven’t bored anyone to death and that someone will find this information useful. If anyone would like I can do a write-up of making a tower.

My buddy is also a woodworker, and after seeing mine he had to have one, so he ordered one and I helped him do the same modifications to it. Took the two of us about 3 hrs to fully modify his cyclone and get started on his tower.

In conclusion, for about 200 bucks (cyclone, pipe, bolts, threaded rod, nuts, solder, etc) and some time I created a pretty dang good cyclone tower that is now mounted in my shop and I get a great joy out of it every time I hit the remote!

If you want the next step in performance from your Dust Collector seriously consider this unit.

Andy

Andy Howard
08-03-2005, 1:54 AM
Picture of completed cyclone tower.

http://img153.imageshack.us/img153/5206/miniimg0729modified3vs.th.jpg (http://img153.imageshack.us/my.php?image=miniimg0729modified3vs.jpg)

Andy Howard
08-03-2005, 1:56 AM
Picture of dust from cleanout on a digital scale.

http://img168.imageshack.us/img168/936/img07393bk.th.jpg (http://img168.imageshack.us/my.php?image=img07393bk.jpg)

Jeff Sudmeier
08-03-2005, 9:44 AM
Thanks for the detailed write up! My next step in my DC evolution is to switch over to larger pipe. After that, I may consider a cyclone like yours.

Thanks again for the tips!

Jamie Buxton
08-03-2005, 12:07 PM
Nice work!
I suggest you tell the manufacturer about how you've improved his product. Hopefully he'll incorporate your modifications, and you'll help lots of woodworker's lungs.

Andy Howard
08-03-2005, 1:41 PM
Jamie,

I have mentioned this to the manufacturer when I was asking questions about his product. He did not seem interested in modifying his product, and I suspect this is due to the added size it would create and the shipping problems associated with it. It would effectively take it from a 20*20*48 box to a 36*20*48 box, which would make it mush more costly and difficult to ship.

Andy

Jamie Buxton
08-03-2005, 9:30 PM
Jamie,

I have mentioned this to the manufacturer when I was asking questions about his product. He did not seem interested in modifying his product, and I suspect this is due to the added size it would create and the shipping problems associated with it. It would effectively take it from a 20*20*48 box to a 36*20*48 box, which would make it mush more costly and difficult to ship.

Andy

Dang. What's the line about leading a horse to water?....?

Stu Ablett in Tokyo Japan
08-04-2005, 7:44 AM
Great write up and a great solution!

I recently finished my cyclone, I used Bill Pentz's plans, but I have to say, your solution sure looks a lot easier!!

The again, I bet the shipping to Japan would have been a killer!

Nice Job!

PS my cyclone adventure starts here......

http://www.ablett.jp/workshop/cyclone.htm

Cheers!

Les Spencer
08-04-2005, 11:57 AM
Andy,

Great info.:D :cool: What size motor did you use? How hard is it to dump the can? Did you raise the unit to facilitate dumping? Did you use the Fram filters? If you help someone else build a tower will you take more pics to post?

I would like to convert my 2hp Grizzley as I too am very concerned about fine dust for health reasons.

Andy Howard
08-04-2005, 1:11 PM
The blower is a "claimed" 2 HP motor from harbor freight, but we all know that is not the case.

I did raise the can off the ground, and it makes dumping the can really easy.

I did not use the fram filters. I used a filter from wynn environmental.

If someone in my area wants to get one and take pictures I will be glad to help them convert it, but I have already done my friends, and I dont think anyone in my woodworking guild would be interested in it.......I think in a lot of their eyes I am too young to know anything.

frank shic
08-04-2005, 1:19 PM
andy, great job!

i was just perusing woodworker's association about two days ago and came across a thread mentioning stu ablett and his adventures in japan so i clicked on the link and was UTTERLY AMAZED at what's he been able to BUILD and SALVAGE there in the land of the rising sun - especially the cyclone! so i checked out bill pentz's site and thought, "gee, 20 hours seems like a LOT of time with one daughter and another on the way..." so i looked around and found the cycloneseparator web site and wondered if it might be a good alternative.

LO AND BEHOLD andy posts this message and stu ablett actually responds to it as well!

coincidence or fate? :D

Dan Forman
08-04-2005, 5:40 PM
Dang. What's the line about leading a horse to water?....?
You can lead a horse to drink, but you can't make him water.

Andy---Looks like a great job on the cyclone conversion, well worth your time and effort.

Dan

Dennis Peacock
08-04-2005, 7:37 PM
Dang. What's the line about leading a horse to water?....?

<B> You can lead a horse to water, but if you can get him to float on his back? THEN you've got something!!!!</B>

Looks like you DC setup is doing a very fine job. :D It's always nice to have cleaner air to breathe while working in the shop. :D

Les Spencer
08-04-2005, 9:56 PM
Andy,

What is your area? Don't pay any attention to anyone who thinks you are too young to be knowledgeable:p . I am a senior citizen who has learned alot from the younger generation. :cool: Many of the upcoming great woodworkers are from your generation. :D

Andy Howard
08-04-2005, 10:08 PM
I am outside of Greenville, SC.

I have got to be the youngest one in our 300+ woodworking guild. I bet the average age is 30 years older than me, maybe higher!

Andy

Stu Ablett in Tokyo Japan
08-05-2005, 7:37 AM
I am outside of Greenville, SC.

I have got to be the youngest one in our 300+ woodworking guild. I bet the average age is 30 years older than me, maybe higher!

Andy

Andy, I consider you one lucky SOB :D

Out of the 300+ there has to be a few of them oldtimers who are willing to teach you some stuff, and in return a younging like yourself can always be put to work lifting heavy stuff;)

My kids are 9 and 11, and I learn from them about stuff all the time!!

Cheers!

Stu Ablett in Tokyo Japan
08-05-2005, 8:18 AM
andy, great job!

i was just perusing woodworker's association about two days ago and came across a thread mentioning stu ablett and his adventures in japan so i clicked on the link and was UTTERLY AMAZED at what's he been able to BUILD and SALVAGE there in the land of the rising sun - especially the cyclone! so i checked out bill pentz's site and thought, "gee, 20 hours seems like a LOT of time with one daughter and another on the way..." so i looked around and found the cycloneseparator web site and wondered if it might be a good alternative.

LO AND BEHOLD andy posts this message and stu ablett actually responds to it as well!

coincidence or fate? :D

Frank it is funny how life works, but don't fight it!!

You don't have to make the cyclone in one weekend! :p

I'm so very pleased with mine, just the other day I empited it for the first time, the bin was less than half full, maybe 8 to 10 gallons of sawdust. I then checked my clean out at the bottom of my filter stack........

http://www.ablett.jp/workshop/images/cyclone/filter_stack_cleanout_drawer_check.jpg
Yep, nothing.

I then put the drawer back in and lightly beat the filter stack and then used compressed air to blow back on the filter stack, trying to dislodge any dust on the filters....

Yep, still NOTHING!! I could not believe it!

I'm not trying to rain on Andy's parade here, just saying that the design from Mr. Pentz's site really works.

I could, when I ran my hand accross the bottom of the drawer just make out some dust on my finger tips..... :D

Man do cyclones rock!

Cheers!

Mike Weaver
08-05-2005, 8:26 AM
<snip>
I then put the drawer back in and lightly beat the filter stack and then used compressed air to blow back on the filter stack, trying to dislodge any dust on the filters....

Yep, still NOTHING!! I could not believe it!

I'm not trying to rain on Andy's parade here, just saying that the design from Mr. Pentz's site really works.

I could, when I ran my hand accross the bottom of the drawer just make out some dust on my finger tips..... :D

Man do cyclones rock!

Cheers!

Great info! I was debating on whether or not to add a drawer like you did Stu. I think I can safely omit it based upon your and Andy's observations.

Cheers,
-Mike

Stu Ablett in Tokyo Japan
08-05-2005, 9:07 AM
Great info! I was debating on whether or not to add a drawer like you did Stu. I think I can safely omit it based upon your and Andy's observations.

Cheers,
-Mike

Mike, I'd still put it in there, because if you can check, you might find some sort of problem, for example if you get a clog in your cyclone (why you would not wear sneakers is question that needs to be answered...... ;) ) then the dust may get through the cyclone to the filters, this would be a good way to see that.

It was not much work, so I'd still put one in.

Cheers!

Mike Weaver
08-05-2005, 9:28 AM
Mike, I'd still put it in there, because if you can check, you might find some sort of problem, for example if you get a clog in your cyclone (why you would not wear sneakers is question that needs to be answered...... ;) ) then the dust may get through the cyclone to the filters, this would be a good way to see that.

It was not much work, so I'd still put one in.

Cheers!

Stu,
I'm not sure we're on the same wavelength, but I've been wrong before.

I'm still doing the drop box w/ a wide, hinged door, but I'm just skipping the nice drawer within that drop box. I can always add it later.
(I need to post progress pics sometime soon so that my garbled dscriptions can be understood):eek:

As to clogs in my cyclone - I never wear them, so that point is moot. ;)

Cheers,
-Mike:D

Mark J Bachler
08-05-2005, 9:49 AM
Thanks much Andy for the info. I have the same cyclone hooked up to a 3 hp Powermatic. I noticed the same thing about the lack of a neutral vane & the center tube length. I was also thinking of adding an air ramp inside. It works pretty well as is for the money, but the modifications seem to be pretty simple, except for the ramp which I'll have to think about.

Thanks again
Mark B.

Stu Ablett in Tokyo Japan
08-05-2005, 11:35 AM
Stu,
I'm not sure we're on the same wavelength, but I've been wrong before.

I'm still doing the drop box w/ a wide, hinged door, but I'm just skipping the nice drawer within that drop box. I can always add it later.
(I need to post progress pics sometime soon so that my garbled dscriptions can be understood):eek:

As to clogs in my cyclone - I never wear them, so that point is moot. ;)

Cheers,
-Mike:D

OK Mike, I see what you mean, sure the drawer I put in the clean out drop box is overkill, but I was waiting for my filters to arrive, so I had time to kill! Lucky they came when they did, or that box would have been made from Ash with dovetailed corners!! :D

Cheers!

Andrew Ault
08-05-2005, 11:56 AM
I have limited space, but want to improve dust control. What do you think of making or buying a cyclone and just venting it outside instead of a filter? It looks like a cyclone gets almost everything.

Mike Weaver
08-05-2005, 1:25 PM
I have limited space, but want to improve dust control. What do you think of making or buying a cyclone and just venting it outside instead of a filter? It looks like a cyclone gets almost everything.

If you do that, you need to be cognizant of where the replacement air will come from. In other words, you'll draw replacement air from *somewhere*...could be a smoke filled chimney, etc...

-Mike

Andrew Ault
08-05-2005, 1:38 PM
That's good thinking. In my case though the air will come through my open garage door. I would probably vent out the side of the garage. Any additional air coming through the open door would be entirely welcome by me. :)

Bill Pentz
08-05-2005, 1:39 PM
Andy,

I’m impressed with your modifications, but have a few points for people to consider before buying or building a cyclone dust collector.

With only two exceptions every hobbyist cyclone and cyclone plan available still uses an inappropriate cyclone design. All but WoodSucker and my design sold by Clear Vue Cyclones are downscaled versions of the huge agricultural cyclones we see outside most large commercial woodworking facilities. And no, the new Grizzly that borrows heavily from my design works like the rest because they made too many compromises. This agricultural cyclone design that everyone else sells uses very high internal turbulence to break sand and dirt loose from cotton, blows the cotton out the cyclone top and drops the sand and dirt into a collection bin. A little tuning makes this design work great for large woodworking firms because it separates and drops the heavier material into a dust bin and blows the remaining fine airborne dust out the cyclone top into the outside air. This type of design gives almost exactly the same efficiency of a trashcan separator lid.

Bringing these units indoors with open filters makes a great chip collector, but trying to turn them into a good fine dust collector creates such a nightmare of problems that almost every hobbyist cyclone vendor is now abandoning this design as quickly as they can. Cyclones are well understood and have been used for more than fifty years, so downsizing one of these for hobbyist use is easy. We need a 13.5” in diameter 54” tall cyclone powered by a 7.5 to 15 hp blower depending upon shop tools, ducting and other resistance. With most hobbyists unwilling to buy or pay for the power to run, let alone having home wiring to support this big of a motor, hobbyist vendors made lots of compromises to permit using a smaller motor. They went with larger diameter cyclones because the bigger the diameter the less hard the motor has to work to turn the air inside the cyclone. Unfortunately, making a cyclone diameter large enough to power with a typical up to 2 hp dust collector blower requires a 5’2” diameter cyclone that stands over 20’ tall. Oneida-Air did a great job with their early cyclone design compromises building what was then the best chip collector available. They went with 18” to 22” diameter cyclones, used 1.5 to 3 hp motors, and traded fine dust separation for a shorter cone. These make great chip collectors but terrible fine dust collectors.

Unable to change the motor or cyclone size, most vendors simply added finer filter bags or cartridges. With close to 100% of the finest dust blowing into these filters they plug quickly. A clogged filter kills the airflow needed for good fine dust collection. Cleaning filters is an unpleasant chore and cleaning ruins these expensive filters quickly. My web pages showed back in 2001 what was needed to help this design work better. The consensus was then and is still that fixing this design to work as a good indoor fine dust collector costs more and takes longer than building a new cyclone from scratch. This is why I rolled up my sleeves and did the research, engineering and development to provide hobbyists with a better unit.

bill

Andy Howard
08-05-2005, 1:44 PM
Thanks much Andy for the info. I have the same cyclone hooked up to a 3 hp Powermatic. I noticed the same thing about the lack of a neutral vane & the center tube length. I was also thinking of adding an air ramp inside. It works pretty well as is for the money, but the modifications seem to be pretty simple, except for the ramp which I'll have to think about.

Thanks again
Mark B.

Mark,

I did try to add an air ramp, but just couldnt get it instaled properly without an extra person and a welder of some sort. I am sure someone with more skill would be able to do it no problem.

According to Bill Pentz, the neutral vane "generates about 1/3 better performance" than without one.

The air ramp helps more with the very fine dust separation.

I am not saying it isnt worth doing, just that the neutral vane is a much bigger improvement and very easy to do. The Air ramp is a bit harder, as you have to have a good way to attach the metal together while bending it in to place, and that is somewhat difficult without a welder.

If you have this cyclone you should definately do the mods to it and you will see a big improvement.

Andy

Stu Ablett in Tokyo Japan
08-05-2005, 1:52 PM
Sir;

I want to publicly thank you for the great design of the cyclone that I built, Thank You VERY much!! :cool:

The cyclone works very well, and I want to also thank you for the help and the encouragement you gave me along the way as I was fitting it together and bothering you with questions.

I know that you have put a lot of time and effort into your research and into your homepage, and I also know that you have had to swim against the current on this subject to some degree, I'm sure glad that you took that time and the effort and braved the current to make this all availible for the world to see.

Thanks you, just does not seem like enough, but unless you are coming to Tokyo any time soon that will have to do.

You guys, Bill's cyclone rocks, it does exactly what he says it will and I'm so very happy that I made the leap to build it, I will never regret it. I'm much better off now than I was with that messy, noisy dust collector.

Bill you da man!!

Cheers!

Mike Weaver
08-05-2005, 2:09 PM
<snip>
Thank you, just does not seem like enough, but unless you are coming to Tokyo any time soon that will have to do.

<snip>


Actually, Bill solicits donations via his web page and has a paypal account for anyone so inclined...

Cheers,
-Mike

PS I couldn't agree more.
</snip></snip>

nic obie
08-05-2005, 2:18 PM
I also would like to thank Mr. Pentz for the time and trouble it took to develop such a great DC unit.

The one I built that's powered by two HF blowers works great. It's been over a year now, and I haven't yet had to clean my filters.

Thanks again Bill.

nic

Stu Ablett in Tokyo Japan
08-05-2005, 3:22 PM
Actually, Bill solicits donations via his web page and has a paypal account for anyone so inclined...

Cheers,
-Mike

PS I couldn't agree more.


Yes I know, I've done that in the past, and I just did it again! :D

Justin Dreier
08-19-2006, 9:24 PM
Andy - I followed your mods on this $159 cyclone. I have the 7" pipe going down through the cyclone and it was about 4" longer than what is suggested on Bill Pentz's web site. I added the neutral vane also. Thanks for noting that the top comes of pretty easy on this unit.

I also ground off the rivots and sealed the unit up good with sealer. I have a HF unit just like yours and am surprised you have so much efficiency on the cyclone. Good to hear. I elected to build a blower using a HF 3hp motor (AKA 5hp motor for only $60 bucks). I might have tried to use the HP 2hp blower I had if I read your post sooner.

Anyway, the cyclone purchase and mods you provided is a really good way to step into the world of woodworking with a cyclone.

Regards, Justin

Bill Pentz
08-20-2006, 10:50 AM
Justin,

You also deserve another well done too.

Still, for those considering these units I again clarify that these are not efficient fine dust separators, so are best used without filters and should be exhausted directly outside. Pumping lots of fine dust into filters quickly ruins filters from over cleaning and the high silica (glass) content in wood rapidly cutting up our filters quickly turning even good fine filters into sieves that pass most of the finest dust. Likewise, the cost and time to buy then modify one of these often exceeds the cost to build or buy a far more efficient separating cyclone based on my better separating design.

OSHA gathered sawdust from hundreds of large woodworking shops, and measured that dust. They found on average woodworking dust is about 85% heavier sawdust and chips and about 15% fine airborne dust. Airborne dust consists of small dust particles that do not immediately fall out of the air. Most airborne dust is sized 30-microns and smaller, with 30-microns being about one third the diameter of a human hair. We all know from working with MDF and doing some operations like power sanding that we sometimes generate close to 100% fine dust and other times like when planning we generate near zero fine dust. So the amount of airborne dust we make will vary considerably.

Going after that 85% heavier dust is known as “chip collection” and means collecting the same stuff we would otherwise sweep up with a broom. Going after the remaining 15% finer airborne dust is known as fine dust collection, something most hobbyist tool, dust collector, and cyclone vendors do not provide in spite of advertising claims. Sadly, vendors like this cyclone maker test with heavy chips to make incredible separation claims, yet decades of testing shows cyclones based on this basic design provide about the same 85% separation by weight that we get from a far less costly trashcan separator.

This remaining 15% of the finest airborne dust poses serious short term and long term health problems. We can quickly become sensitized to some of the more toxic woods if we have too much exposure. That sensitization can lead to serious immediate reactions such as severe asthma attacks and worse. We all also develop long term damage from too much fine dust exposure. Our bodies do a good job clearing dust down to about 10-microns, but have trouble with finer stuff getting lodged in our tissues. Particles sized 1-micron and smaller pass directly into our blood and can get lodged anywhere. Over time the chemicals and toxins in that dust, plus the silica (glass) will cause almost all to get ill. At typical hobbyist exposures this may take a decade or two, but we have over forty years of insurance data and medical tests that show all are affected with about one in eight developing serious problems. Sadly this often occurs so late in life that many do not tie their respiratory problems to this exposure.

Dust sized 10-microns and smaller is invisible without magnification, creating a big problem for hobbyist woodworkers. Unlike most large woodworking facilities that blow the finest dust away outside, we mostly trap this fine dust inside where it often builds to dangerously unhealthy levels even in shops that do minimal woodworking. It takes six months or more for this dust to dissipate. During this time it gets broken down into finer particles plus gathers extra toxins as it is broken down my molds, mildews, bacteria, yeasts, etc. I know from personal experience this buildup can be dangerous, especially when working with the more toxic woods like walnut, red oak, cocobolo, rosewood, etc. I thought I was well protected because I used the “best” advertised cyclone and “best” oversized 1-micron filter. After landing in the hospital, I did not believe my new respiratory doctor, so had my shop tested. Although praised for such a clean looking shop, my shop after over three months of no woodworking still failed its fine airborne particle counts from just turning on my cyclone with doing no woodworking. My near new fine filter stored up and freely passed most of the fine dust.

This cyclone you modified is near identical to almost all other current hobbyist cyclones and the one I bought. They are all built on plans from the New York Dept. of Labor, Division of Hygiene Engineering published in August 1962. This cyclone design has its roots in a basic agricultural cotton cyclone built with very high internal turbulence to break sand and dirt from cotton fiber. When used with woodworking these agricultural cyclones do an excellent job of “chip separation” breaking the fine dust from heavier and dropping close to 100% of the heavier sawdust and chips into a collection bin while and separating near 0% of the airborne dust particles that it blows right through the cyclone. In short, these cyclones provide almost exactly the same 85% separation efficiency that we get from a trash can separator lid. Instead of just blowing this fine dust directly into the outside air as done by large commercial woodworking cyclones, Delta built their cyclones to blow the fine dust into very open filters that freely pass the airborne dust. These big filters catch the chips and sawdust if the dust bin gets full because cyclones with a full bin blow everything right through. The big commercial units don’t have this problem because they have automatic bin emptying, or sensors that shut down the cyclone when the bin becomes full.

Even with all the changes from my Cyclone Modifications pages this basic cyclone design will still pump nearly 60% of the 30-micon and smaller particles right through. With this fine dust full of silica (glass) that trees use for strength, that dust loading will soon cut and tear its way through fine filters leaving them wide open and of little use to protect your health from the finest unhealthiest dust. Worse, unless you use a particle counter or pressure gauge to know when it is time to change filters, you are not going to see any problems until well after the finest dust levels have become dangerously unhealthy. That is why I strongly recommend venting these cyclones directly outside with open filters and no air returned into your shop.

My own testing showed my cyclone design was over 90% efficient at separating off these fine particles before the filters. This greatly increased filter life, reduces cleaning needs, and provides much better long term health protection. Recently I received the early testing results from a major medical school. They provided some nice praise for my design saying it was more than twice as efficient as any other hobbyist cyclone they tested showing better than 90% separation on the 30-micon and smaller particles.

bill

Stu Ablett in Tokyo Japan
08-20-2006, 11:26 AM
Keep up the good work Bill, I want to thank you again publicly for your work on this front, if it was not for your cyclone research, I would have been breathing this crap in forever, and or had to give up woodworking.

My Pentz designed cyclone just simply works.

Cheers!

ed mirzay
08-20-2006, 12:12 PM
Great info, thanks!

I too was worried about fine particle filtration in my basement shop, I had a sub-2 micron canister that did an adequate but not good enough job of cleaning the air.
I bought a trash can separator to catch the majority of the small particulates and then routed the exit air outdoors. Can't beat that for evacuating the really fine particulates! For those that have a similar setup (basement shop) but are leary of cutting a hole in your house, you won't need to if you have a window. I built an mdf insert with a 6" pipe sticking out of it that mounted on the outside of the frame. When I open the window about halfway, the molding I installed on the insert meets the window frame. I then crack a window on the other side of the basement for the fresh air return. Since I did this my shop has remained amazingly dust free. I get better suction from the DC as well since I removed many restrictions.

Julio Navarro
08-20-2006, 12:25 PM
Of course I have to chine in!

I was pleasantly surprised to see how you located your cyclone Andy! Its int the exact same place as mine!!

I almost thought it was!

I, like Stu, built Bills' design and except for having installed a bad motor from HF it is working like a charm now that I have a 3.5 hp Leeson (shortly to be replaced with Ed Morganos' 5hp... If you hear the 3.5HP and how it sucks I cant even begin to imagine how the 5hp will work, I may just get sucked in)

Here a pic of mine you can see its in the same location as yours.

By the way, after thanking BIll Pentz for all his invaluable information I have to thank Stu for his intricate description of how he built his cyclone. I dont think Stu will know just how many times I ran to the computer from the shop when I came to an impass to look and see how he had done his then ran back to the shop shouting.."of course!!!"

On piece of advice to any one who is thinking about building a cyclone from Mr Pentz's design...get a power sheet metal cutter! It will pay off over and over again.

Heres a pic of mine:

http://www.sawmillcreek.org/attachment.php?attachmentid=38291&d=1147395419



This is it now with new base:

http://www.sawmillcreek.org/attachment.php?attachmentid=42481&d=1152549014

Stu Ablett in Tokyo Japan
08-20-2006, 12:35 PM
Glad to know I helped, and your advice about the power shears is DEAD on, my hand hurt for a week :D

Allan Johanson
08-20-2006, 12:51 PM
Glad to know I helped, and your advice about the power shears is DEAD on, my hand hurt for a week :D
I just used a jigsaw with a metal-cutting blade. Keep the metal supported close to the cut or else the blade might catch and the jigsaw will be bouncing up and down instead of the blade. BTDT :rolleyes: :D

Also, most importantly, wear a full face shield when cutting metal because little pieces of metal go flying.

Cheers,

Allan

Bill Pentz
08-20-2006, 1:21 PM
I just used a jigsaw with a metal-cutting blade. Keep the metal supported close to the cut or else the blade might catch and the jigsaw will be bouncing up and down instead of the blade. BTDT :rolleyes: :D

Also, most importantly, wear a full face shield when cutting metal because little pieces of metal go flying.

Cheers,

Allan

Allan,

I really agree on the need to wear a face mask when sawing metal. My son cut a lot of these metal kits and we tried just about everything.

We started with a big pair of metal tin snips, but those will kill your hands soon. We shifted to the compound tin snips which cut slower but give the extra leverage to save the hands. Unfortunately, ours had serrated edges that messed up the cuts. My jig saw worked fairly well once we also learned to properly support the metal, but it was slow and we were going through the Bosch metal cutting blades by the gross. I then bought an electric nibbler that cut little 1/8 moon shaped pieces. It worked slowly and those pieces went everywhere. We then bought an air powered cutter that worked by cutting a 3/16” strip with a moveable blade moving between two fixed blades. That worked best yet, but it was a cheap unit and only lasted a few cyclones before biting the dust. We next got a good quality electric metal sheer. That worked well and allowed just following a plywood template for a quick and pretty accurate cutout. I recently helped a friend cut one with a HF metal sheer and it worked as quickly as our more expensive unit and only cost $20. I don’t know if that was a sale price or not, but is the way I would recommend going as we were done with the cutting in less than an hour. We spent longer than that doing the layout.

Regardless of some saying these are a pain to build, I still get a few people each week asking questions and building their own cyclones very successfully from my plans.

bill

Jim C Bradley
05-25-2007, 12:12 AM
Hi,
I went through this entire thread. There is a heck of a lot of information here.
Thanks a Million!
Enjoy,
Jim

bertrand challier
08-04-2010, 6:51 PM
Andy , could you post some pictures?
I want to do the exact same thing.
Thank you.
Bert

David Helm
08-04-2010, 7:59 PM
I'm in process of producing my MacIntyre cyclone powered by a Jet 2hp DC. I sure would like to see pictures of your set up!

Jim O'Dell
08-04-2010, 8:20 PM
Keep in mind guys, this thread was started 5 years ago!!! Hopefully these guys are still around and will post pictures. I know Stu is no longer here at the Creek, but you can do a U-tube search on Stu's Dungeon Workshop and come up with some videos of his. Jim.

Karl Card
08-05-2010, 12:55 AM
very good write up... I have a cyclone just like what you have, got it in a trade. I am also running a 2hp dc with a 2hp leeson motor on it. My first thing that I am going to try though is to get the dust outside in a box.... if that cant be accomplished then I am going to try the setup you just described.