I spent Friday and Saturday doing some serious cleanup in the shop and planned to spend some time with my dust collection system and figure out why it wasn’t collecting very well. I have the Jet 650 cfm collector connected to a hard piped manifold system with blast gates that I set up depending on which tool I’m using.
For the past year or so, my DC has seemed pretty anemic and I assumed that it was because I was using it much more than before – and I was even thinking about upgrading to a bigger system.
When I removed the collection bag, I decided to also remove and clean the upper bag since I hadn’t done that for a lonnnnng time. When I shook it out, I was astounded by the amount of dust that came off so I hosed it off. Then I went bananas and tossed it the washing machine with my work clothes – after promising SWMBO that I would clean the washing machine if necessary.
After the bag dried, I put everything back together and fired it up. I was amazed to discover that the air flow thru the gates had almost doubled. I have a gate at the workbench set up with a reducer so I can connect my random orbit and detail sanders and it was actually “whistling” because of the increased air flow. Playing a bit, I found that I could open two gates and still have about the same air flow that I had before I cleaned the upper bag.
The moral of the story is that that upper bag needs to be cleaned once in a while. It’s essentially an exhaust filter and – if it’s dirty – severly restricts the air flow thru the system and really bogs it down. As a trained professional mechanical engineer, I should have known that and I’m almost embarassed to tell this tale but I’m willing to take the ego hit if it helps someone else improve their DC system performance.
I’ll watch this thread and try not to pout too much when others reply with “everyone knows that”!! – lol
Replies
My top bag clogs too. Eventually the pressure can force it, or the plastic bag below, off its rim. Choking dust flying everywhere - hit off switch and stageer outside for a while, coughing and retching. I do take the thing off, turn it inside out and beat it against a wall outside sometimes. If I'm in a hurry I hit the bag with a stick while the extractor is running to dislodge the stuff.
There's got to be a better way. The standard DC with a cloth upper bag and plastic lower is so primitive. And securing the bag with the stupid band clip needs at least three hands, and a spare lung or two
"There's got to be a better way. " It's called a cannister filter. You can retrofit many of the all-bag DC's.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I think there's a better way than that: the cyclone dust collection system.
Well, sure, if you got the $$ for one. I'm trying to stay in the same general ballpark as the OP started in.
I started looking at DC's just about the time the Jet cannister model came out. Never even considered getting a top-bag DC!! Can't see the sense in collecting all that dust, just to spread a bunch of it all over myself when emptying out the bag! Granted, I lucked out and got a new-in-box for a great price from a Knots friend who was in a weird Amazon "can't return it" pinch, but still I would have held out for one, eaten mac-and-cheese for months to get a cannister rather than a bag.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FGI agree, the cannister filter is great. It worked wonders for me when I first replaced the bag on my PSI collector. BUT - the cannisters need 'cleaning' too. My unit has a handle on top to rotate and shake the dust out of the pleats on the filter. I now use it regularly.Jerry
Jerry, sorry if by omission I implied there was no cleaning involved with the cannisters. Of course there is! Spinning a handle or dragging out the compressor hose sure beats the alternative with bags though, eh? ;-)forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG - I agree that we need to keep "the top" clean. I just wish there was a tidy way to empty my 'bottom' bag. I have stopped dust leaks around the top of the collecter bag by installing a strip of self adhesive, sponge rubber, door/window insulation. Now if I just remember to empty the bag when it is about 3/4 full rather than wait until it is plumb full to the top.Have you tried the Ecogate "Greenbox' controller? It starts the DC and opens the appropriate blast gate when you start the tool. Had some kinks at first but it works great now. I wouldn't be without it.Jerry
Jerry
Emptying the dust out of the bottom bag and not standing in the cloud has always been the self defeating aspect of the system. A few years ago I changed the lower part of the collector to use large trash bags. This way I don't have to dump the dust. Just close the bag and stack them in the corner. You can find the details in Fine Homebuilding, November 2003, #158, page 30.
Corry
I don't get it.I disconnect the lower bag, slip a green garbage bag over it then gently flip the combination over and gently remove the collection bag from the garbage bag leaving all the sawdust inside. I get an absolute minimum of dust loss. I guess if I actually "dumped" the contents into ??? then there would be a cloud of dust.
Emptying the lower bag is easy if you do it early. I empty mine when it's 1/3 full, and it's no hassle at all.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
Thanks for the info. My only problem with dust is when I wait too long to disconnect and empty the bottom bag. Disposal is simple: We live in a rural area and 'the lovely' enjoys the mulch for her gardens. I just need to remember to stand upwind when I dump the bag.
'
Jerry
I am curious, why do you say that a cyclone system will solve the problem?
MikePardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I'm no expert at this, but I recommend reading the information on Cyclones on the billpentz.com site that "OB" listed above. That's an excellent site that should tell you everything you need to know about dust collection.I only said cyclone because from everything I've read, a properly designed cyclone system is superior to any other dust collection system out there.
The reason I asked you is because I too thought that a cyclone system would be better, heck they cost more so shurely they should work better. However I kept noticing that the CFM and suction numbers were considerably lower on cyclone units when compaired to bag/canister units of the same HP. So I called Grizzly and asked their tech guys if the numbers were derived through different testing standards.... "Nope", he said. So I asked if there is some difference in the "real world shop enviroment" as in once the system is hooked up to duct work and the bag is half full of dust/chips, did the cyclone perform better in those conditions.... He responded, "Nope, the bag/canister units will still perform better given the same HP and fan". So I asked him "what can you tell me to convince me that the cyclone is worth the extra money?" He replied that "cyclones seperate the dust from the heavier chips". I was truly ready to buy their 3 horse cyclone when I called, I had the card out and everything, but after that I told him I needed to think about it a little longer. Well I called up Oneida and Penn (again) and asked them the same general questions to which they sort of him-hawed about the cyclones ability to seperate the chips produced from a planer from the dust from a sander.
I have ran a small, fulltime, profesional shop for a few years now and I can't see the advantage of having to empty two containers and dump them into one bag so I can throw it away. So I talked to my oldtimer friends who have big shops and here was their take.....
In the old days cyclones were outside the shop and would drop all the heavier chips into a trailer or dumpster to be hauled to the landfill, the lighter dust was blasted out the unfiltered top of the cyclone where it was spewed into to breeze. Once the "Clean air people" started "poking around" they said that was not kosher anymore so all the old school cyclones were replaced with bag systems. So they weren't using the cyclones because of their performance, but because they didn't have to worry about the dust at all.
I still havent bought a new dust collector yet because I am wondering if any one can explain the advantage of a cyclone. I will say I do see the advantage in very large shops where their chips are hauled off in huge trailers and the dust is handled seperately. but in the 2 to 5 horse range I fail to see any advantage.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I have the Penn 3 horse cyclone. I went with the cartridge type filters with the clean out at the bottom. In the 3 years I've been using it (heavily) with planer, shapers, 26" double drum sander and everything else I have taken maybe a quarter of a cup of fine dust from the filter clean out. And yes I blow 30 psi. air through the cartridge pleats about monthly. The drum under the cyclone has everything in it, chips and fines and needs to be emptied twice a week. It holds 40 gal. if I remember right. I bought it because I was tired of the cloud of dust that spewed from the bags when my old bag system fired up. I can light off the cyclone and not even see any particles in a flashlight beam. For what it's worth I'm tickled with it.
Since the house is on fire let us warm ourselves. ~Italian Proverb
You can buy the same pleated filters for a bag style collector and get the same level of filtration. In fact a lot of the after market pleated filters capture more than the OEM cyclone filters. I am glad that your system is effective at collecting dust. I think that you could have spent $500 bucks less and got a system with more power. At least that is the conclusion I am coming to. Again I was convinced that cylcones were the way to go, now I am trying to find someone to tell me why they are better. It sounds like you are saying that yours filters the fine dust, but if a standard unit has cartridge filters it will work just as well, or better.Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I had a bag type system that I retrofitted with cartridges and plastic bottom bags. I have no done any scientific testing but I believe the cyclone works better. The cartridges on the cyclone don't load up with the fine dust so the suction stays stronger longer. I used to have to spin the handle and back flush the cartridge a lot when using the sanders, now I don't. I hated wrestling with the bottom bags, you needed three hands to put them on and there was always a cloud when you took them off. The cyclone also seems much quieter to my ears. I have far from the ideal ducting yet it removes all the chips and dust from my machines and the insides of my again far from ideal flex hoses are clean as a whistle. my longest run is well over 30 feet. For me it was well worth the extra money. Also I don't have to worry any more about a chunk of metal going into the impeller, one less spark source in a dust system is a good thing. Not trying to steer you one way or the other, just relating my own experience.
Since the house is on fire let us warm ourselves. ~Italian Proverb
Dgreen,
I welcome your experiences. I am still trying to figure out what is best for my shop. You bring up a great point about metal things and wood chunks not getting to the impeller. I don't use the DC for sweeping the floor for that reason.
Is there a difference in horse power between your new system and your canister conversion system, and did you old system keep the pipes clear as well?
Why do you think the filters require less frequent cleaning on the Cyclone? Does some of the not-so-fine dust that would previously have gone to the filter end up in the can with the cyclone?
MikePardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Same hp on both systems, I have longer runs and more hookups now than I did before so I can't do a good comparison as far as the hoses go. Everything, large chips to fine dust has gone in the can except for the less than a cup in three years in the filter cleanout. The filters require way less cleaning than before because everything winds up in the can.
Since the house is on fire let us warm ourselves. ~Italian Proverb
OK, now I see. Ideally very little if anything should make it to the filter. That makes sense to me now. The cyclone is not trying to seperate the haevy and fine dust..... but seperate ALL the dust from the airstream. I suppose that is why the filters seem so small on the Cyclones, very little dust should make it there.
Am I understanding the advantage better now?Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Hi Mike,
Yup, in a nutshell a good cyclone will separate the vast majority of dust from the airstream before it even hits your filters. This way your filters will stay cleaner, longer and your airflow will stay higher, longer.
The filter on a single-stage DC is subjected to a massive amount of dust and can easily clog in a very short period of time. This will vary from shop to shop depending on the type of wood being milled and the machine they are using. This is where you hear those wide variety of opinions. I know a guy who would clog his filter bag in as little as 15-30 mins when using his drum sander or sanding with his lathe. He switched to a cyclone and he goes two months between cleanings while flowing lots more air (read that as capturing even more dust).
A couple points to clarify: When you have two DCs, a single-stage and a cyclone with the same motor/fan combo, the single-stage DC will initially flow more air. Why? Because it takes power to spin the air in a cyclone. This extra resistance will make it flow less air initially......but.....as the filter gets dirtier and dirtier on the single-stage DC the airflow will drop. Over time, the cyclone with the cleaner filter will flow more air. How much time to do this will vary based on the shop.
About the part of comparing advertised airflow ratings "being tested the same way". Pure rubbish for the most part. I constantly see 2HP single-stage DCs being advertised at 1200-1600cfm. You will see about half that in your shop - MAX. These are "free air" ratings with only the blower. No inlet cover plate, no filters. With a cyclone, the cyclone must be hooked up so you can't mess with the testing too much. The numbers tend to be more real. Although you still have to watch out.
For a ballpark number of what you might see in your shops, when you see a performance curve graph (cfm vs SP), look around the 6"-8" SP range and you will probably see airflows in that range. It sure can vary a lot though, but please ignore max airflow numbers. You just won't see them.
BTW, I've built my own Bill Pentz cyclone and I do a lot of airflow testing on my DC as well as many, many others. My Pentz cyclone has a max airflow of just over 1700cfm and I'm seeing airflow of 700-1250cfm at various tools depending on the duct run, hood style and the tool itself. Some tools are very restrictive. I just wanted to point out that even my cyclone doesn't operate at the max airflow of a shop-tested 1700cfm.
Cheers,
Allan
For what it's worth, I built my own cyclone from galvanised sheet metal with the scroll built of plywood and sheet metal. The impeller is from Oneida, driven by a 2 hp Baldor motor. It is mounted outside and it exhausts under another building, primarily for noise reduction. The straight blade impeller has somewhat of a siren effect which may be due to my incorrect scroll clearances - I don't know. If I had it to do over again I would try to find an impeller with curved blades. The slightly reduced performance would be a welcome trade off for reduced noise.
When the collection barrel is not full, the amount of dust coming from the exhaust is nearly undetectable. When the drum is full, everything comes out the exhaust. This collector has no problem keeping up with any machine in the shop. I also built my own sheet metal transitions to connect the machines to the piping, but some machines are better than others at gathering their dust so it can get sucked effectively. The planer is best, the Unisaw is worst.
Here's my advice - The two best things you can have are:
1) A demand switch, i.e. when a machine is turned on, the dust collector is turned on. Not real expensive but will require some rewiring.
2)Self cleaning blast gates. If you don't have these, your system will degrade over time due to all the gates being partially open all the time. More money, yes, but better than spending alot of time installing stuff that will fail in a year.
Very informative. Now I understand the advantages. I don't yet have a drum sander but that will change in the future. I can see how the filters will cake up very fast and that would be anoying. Most importaintly I see now that the actual cyclone is more complicated than I thought. It sounds like it must be very acurately engineered to seperate the dust properly. Now I wonder about the Grizzly units.
thanks
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Hi Mike,
Yes, different cyclones will separate the particles differently. Brand "X" might do a poor job and only separate 60% of the really fine dust. Brand "Y" might do a much better job and remove 98% of the really fine dust. Also, different cyclones will have different levels of resistance while doing this separating so you have performance differences there too.
I think the best performing cyclone out there for the hobbyist is the Clearvue (no affiliation). 15" fan combined with a low resistance cyclone design that was made to separate out the vast majority of fine dust. Killer combination.
Cheers,
Allan
Allan,I should have mentined clearvue too. What kind of woodworking machines do you have on yours? Any weaknesses?Pete
Edited 6/25/2006 2:52 pm ET by PeteBradley
Mike,Could you provide a link. The only thing I could find was their displeasure with tests done by Onieda. They do not mention Bill Pentz, and I would be surprised if they wanted to attract any attention to him.Todd
I think you found the page I am refering to. They don't mention Pentz, just that the compairison (and their conclusions that they advertise) are incomplete and misleading. I think they are refering to Oneida, or is it Penn. I had not been to Pentz's site untill it was posted here.There is a lot of information about the workings of the system, though mostly theory aplicable to the DIY aproach, and his whining (sorry that what it sounds like to me) about his situation. I dont care for the self proclaimed maurder type. I talked to Onieda and Penn as well as Grizz. Every one really said the same thing..... they just didn't seem to be able to explain why Cyclones are better in the real shop enviroment, as in how will it save me time or make me more effecient. But thankfully I have Knots! Now I understand the reason for a cyclone. I was all ready to get the cyclone .... then changed my idea to a filter canister style unit... and now I think that the cyclone seems like a good idea, but I have to figure out if the Griz preforms well (keeps the filter clean).
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Something I learned years ago still stands me in good stead today, when you call a company with technical questions dont ask for a salesman. Ask to speak to an applications engineer and if you hit a dead end there ask for the engineer for that product. You will be surprised how often you are successful and the person you talk to will know the answers and be less likely to have a commision or sales report dictating his answers.
Since the house is on fire let us warm ourselves. ~Italian Proverb
Mudman, your post has some intriguing information in it, thanks!
After reading the various posts here, I'm so glad I bought the Jet Cannister collector. Granted, it's too small for a full-time, mega-dust-producing shop. That aside, when reading stories about dust-spewing top bags, hard-to-empty bottom bags, makes the wait that I endured well worth it. No top bag to bother with (just spin the flappers mostly) and gather up the plastic bottom bag and toss it, stick on another one.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 6/22/2006 11:24 pm by forestgirl
I have a small dust bag type dust collector and found by turning it off and shaking and folding the upper bag every couple weeks most of the caked on stuff falls into the lower bag. I also use a large garbage can with the Lee Valley cyclone lid on it that works well enough that I empty it 6 or 7 times before I have to empty the bottom bag.
Sounds like you've developed an excellent technique to deal with the process. Hopefully, others with the bagged DC's will pick up on it! Thanks for the note.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Here is my DC a G1029 & I have the big Grizzly filter & use heavy garbage bags on the bottom I also have a The Woodtek¯ Dust Collector Coupling Skirt adapts dust collectors to use 30-33 gallon metal trash cans.
http://woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM=893-338
I didn't like the way the saw dust built up around the can edge between it & the skirt & fell on the floor when I loosen it. I think if they made it to snap into place like the Jet DC bottom bag with a metal band that went in the inside of the garbage can. My Dc is the older on & I just picked up the 6" intake & will convert it over as soon I I get the duct work together.
Good, better, best never let it rest until your good is better & your better best.
Edited 6/23/2006 11:18 pm by OB
All your questions can be answered on this site:http://billpentz.com/woodworking/cyclone/Index.cfmWhich was posted previously, but its obvious that you haven't read it. Be wary of anecdotal evidence.Good luck,Todd
Does anyone know if the Jet DC-1200 can be retro-fitted with a canister? I looked at the Jet web site but it does not specifically say what models can be retrofitted. I'm guessing it can but I don't want to order anything until I'm sure. I see JET 708739 2-Micron Dust Dog Canister for LG Dust Collectors at Amazon.com for $159.99 (less 20% during June) but I also see a retro kit on the Jet web site. I assume I cannot but just the canister but need the entire retro kit?
John L
There are no canisters for Sears Craftsman DC.
What's the diameter of the base the bag sits on? There might be one out there.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I run into the same problem with my Oneida which has the internal pleated filter. The internal filter as a REAL PAIN to remove and clean so I do take some precautions to lessen the number of times per year I have to go through that specific bit of torture. What I would recommend to you is to not use the dust collector for sanding. I found that the superfine dust collected during sanding is the number one culprit clogging my filter.
I purchased a HEPA filter for my shop vac and use that exclusively for sanding. This filter has a coating on it that allows you to do a pretty thorough cleaning just by tapping it with a piece of wood over the garbage pail. Much, much easier than cleaning "the big one" and it allows me to run the large collector longer between cleanings.
Regard it as just as desirable to build a chicken house as to build a cathedral.
Frank Lloyd Wright
I have the Oneida 1 1/2 HP model and, like you, HATE cleaning the internal pleated filter. Have you considered upgrading to the external filter model, or found a source for modifying the original model? Jim
Jim,
I had not considered an upgrade/conversion, but that is a very good idea. I'll look around and see what I can come up with. Please let me know if you come up with anything. I'm a bit tight for space around my collector (see attached) so any solution will have to take that into consideration.Regard it as just as desirable to build a chicken house as to build a cathedral. Frank Lloyd Wright
I see what you mean. It might still work for you to upgrade to the external filter, but I'm not sure if one takes up space in a given direction or if it's variable. The last time I talked to them I didn't get a clear picture and the $250 or so to upgrade was a turnoff. My space is also restricted, but I might be able to rotate the fan/motor part enough to accommodate the modification. Your shop looks clean enough to pass a restaurant inspection!
Jim,
LOL - never thought about 'cooking' in there! Actually, those pics were taken several years ago and now the shop is even more crowded. Thanks for the complement, I spend several days cleaning before taking the pictures. It does not often look this clean, but I do make an effort to clean as I work and then take a day to do a thorough clean up after each major project. It's a small shop, 20 x 20 +/- that I share with a second fridge, washer, dryer, furnace, water heater, and the back end of the fireplace. So, clean = more pleasant and safer to work in.
$250 sounds like a bunch of bucks for that upgrade. I think I'll keep my eyes open for an alternative.Regard it as just as desirable to build a chicken house as to build a cathedral. Frank Lloyd Wright
650 cfm plus if you have the original 30 micron bags no wonder.
650 cfm DC is a roll around from machine to machine DC with a short hose to hook it up.
I have a 1200 CFM machine & with duct work am luck to get 400 cfm at the tool.
"pretty anemic " how about almost dead?
Take a few hours & learn about Dust Collection. What you & I have is chip collection not dust collection.
http://billpentz.com/woodworking/cyclone/Index.cfm
Looking at the picture of your dust collector I noticed the 'impeller box'. Is it for sound proofing? Or did you make some kind of replacement housing for the original?
It is covered with fir-tex to try to quiet it down but didn't work to good.
I need a muffler. I don't have a place to enclose it inside or outside. It sets next to the exit door for ease of emptying but is also right in front of the electrical breaker box. I can't put it outside because I live & work at an apartment complex & that is where my shop is, so outside isn't acceptable.Good, better, best never let it rest until your good is better & your better best.
I understand the noise issue.It huffs......And it puffs......And it blows the eardrums out!!!!!
Dave, Read your tip this morning and decided to give it a try. I have a two stage system so most of the stuff falls into a 55 gal. drum but there is a filter bag about 16" x 48" that catches the finer dust. Since I bought it used, I've never experienced it with a perfectly clean bag. Wife's out of town so I threw in the washer and just hooked it back up. Definite difference in suction, at least a 20% increase. Thanks!!
Ian -
Glad my experience helped. This thread got much more response than I thought it would. Apparently, we all have a love-hate relationship with our DC systems. I'm not real happy with the band clamps that hold my bags on, but I've learned to deal with them. My serious messes happen when I haven't paid attention to the level in the collection bag and it gets completely full. Then, I have to get out the shop vac - lol.
I know that cleaning the upper bag is going to be a more frequent chore for me. I'm still dazzled with how much better my DC works.
If those who haven't yet gone to & read Bill Pentz's web site you would learn why a certain sized fan & motor & properly sized cyclone body & properly sized & angled intake & properly sized exhaust makes the Pentz cyclone work better than many if not all the other cyclones on the market.
http://billpentz.com/woodworking/cyclone/Index.cfm
This site does have the answers to your questions but you'll have to take the time to read it. I know it like going back to school. Oh well you can go back to school for free here or spend your money multiple times & may still not get what you really want in a dust collection system.Good, better, best never let it rest until your good is better & your better best.
Where are the reviews of cyclones? The comparisons I saw on his site gave no model #'s except for two SMALL Delta units that are not even cyclones. Of the companys listed in the comparison he makes no mention of model numbers and several of those companies make several models of cyclone and several bag type collectors. Which one is he testing? Did I miss something. Lots of good info mixed with a liberal helping of if you don't buy my licensed design you're gonna die.
Since the house is on fire let us warm ourselves. ~Italian Proverb
Last I heard he is either re-writing the reviews, or has caved into the pressure from the big manufactures and their teams of lawyers. I read his reviews a number of times, so I'll give you my summation:The new models by Grizzly, Onieda, and JDS, were not reviewed.Of the all the models reviewed only 2 provided adequate CFM at the source: The Onieda 3 HP, and the Woodsucker. Both of these models had design flaws that resulted in too much fine dust going to the filters. Therefore, they are recommended only if you don't mind frequent cleaning of the filters so that CFM remains adequately high.If you want more information, go to his site and send him an email. He has always been fairly easy to talk to.Todd
> Of the all the models reviewed only 2 provided adequate CFM at the source...There are a lot of statements being thrown around in this thread that I have to take with a grain of salt. Bill Pentz has a strong following and I'm sure his intentions are good. However, if the above statement is true after testing a significant number of dust collectors, I have to question the validity of a testing method that says that there are only 2 "adequate" models out there other than his own design. Likewise, how much is "too much" dust going to the filters? You get the idea.I'd like to hear concrete answers from some of the people who have actually owned the Oneida, Woodsucker, or Griz cyclones for a while. What machines are you using them on? How well do they move chips? How much find dust do you find in your air and in your shop over time?Pete
Hi Pete,
I don't think a small sample of anecdotal evidence will get you the answers you're looking for (reread what I wrote before about varying performance in different shops - different machines - different woods/MDF - different quantities of dust, etc), but FWIW, my homemade Bill Pentz tin can is a very strong performer. I have the 14" Sheldon material handling impeller on it. With this smaller 14" fan compared to the 15" version used on the Oneida 3HP cyclone, my cyclone should be beaten by the Oneida. However, when I compare the performance curve I tested myself on my machine to the posted results of the Oneida on their site, they are very close.
At some points on the curve my DC will be better and at some points theirs will be better. But this is with a smaller fan on my machine. Bill's design is so much more efficient that it'll flow a similar amount of air as a cyclone with a larger fan.
Through correspondence with Bill I found out the Clearvue is maybe 10% more efficient than the tin can specs he posts on his site. Combine that with a now available 15" fan and you can see why I think the Clearvue is a tremendous machine.
BTW, in over a year I haven't had to clean my filters yet. Mind you I haven't made a lot of projects recently, but when I had a typical bag system with a 2 micron felt bag, I had to shake that thing all the time to free up the dust cake to get some performance back.
Anyhow, on to your questions:
I have my cyclone hooked up to a Unisaw with an Excalibur overhead guard, DeWalt 12" SCMS, Delta DJ-20 jointer, Delta 12.5" planer, Performax 16-32 sander. I'm in the process of designing a new hood for my Jet 14" bandsaw. Performance is excellent at those machines, mind you I've taken the time to make my own hoods (except for the Performax which will definitely happen) and I've also optimized the duct runs. My goal is simple - over 1000cfm at each tool and I do the airflow testing myself. My wife has asthma and I want to do all I can to capture as much dust as possible at the source.
Want a key piece of anecdotal evidence? My asthmatic wife has come into my shop as I've been cutting wood with the cyclone and she has no trouble breathing. She couldn't come in when I was doing some metalwork in there (welding/grinding) or when I used a router without a DC hookup.
Keep in mind a cyclone or large DC of any kind is only hooked up to the bigger tools. You can't forget about hand sanders, routers, etc. Even though I'm very proud of my Pentz cyclone, I use my shop vac with a HEPA filter for the small tools. It's the right tool for the job.
About Bill's criteria for testing and how he came up with such a short list of "acceptable" cyclones....well, that's Bill and his standards. They may not match yours. That's fine. A key thing to remember is that Bill is focused on respiratory health and a key part of that is making sure your filters don't get clogged. Clogged filters reduce airflow and also let fine dust get forced through the filter material as the pressure increases. That isn't good if you are concerned about your lungs. A cyclone design that will allow lots of fine dust to get through to your filters will reduce performance.
Oneida has a filter backpressure gauge that will tell you when it's time to clean your filters. Read the link below. They say filters that are up to 3" are OK and 3"-5" should be cleaned.
http://www.oneida-air.com/products/accessories/filtergauge.htm
Now look at the performance graph of one of their cyclones.
http://www.oneida-air.com/products/systems/super_gorilla/performance.htm
This is their 3HP Super Dust Gorilla curve. Suppose a new owner of the SDG hooks up a tablesaw and the performance at that tool places them at the 1100cfm @ 8" SP range as indicated on the graph. (BTW, I'm getting around 1050cfm at my tablesaw right now so this is a reasonable example.)
Fast forward a few months as the filter loads with dust. If 3" of resistance is acceptable to Oneida, add that onto your 8" when the SDG was new. Now you're at 11" SP and the airflow has now dropped to about 700cfm.
700cfm isn't fine to Bill and he'll want a cyclone that will separate more of the fine dust to keep the filters cleaner, longer. Maybe 700cfm is fine to you and other people, but that's where personal choice comes in. We all have different goals and these personal goals aren't "wrong" or anything like that. It's just that we are coming from different backgrounds and have different standards. That's cool.
BTW, the numbers above are just examples to illustrate the issue with filter loading. FWIW, I have a dedicated gauge to monitor the pressure in my filters and after a year I'm at 0.5" of resistance. Bill's design really does work. I'm not saying the others don't work - but I'll be able to see for myself when a local guy gets his SDG up and running. I'll monitor the filter loading myself and compare it to mine.
Cheers,
Allan
Allan,Thanks. It's not anecdotal evidence that I'm looking for, so much as filtering the many comments to separate real-world experience from speculation and hearsay. I appreciate your taking the time to comment extensively based on experience. I'm sure you're also aware that the fansize=CFM implication is bogus on its own since it doesn't take into account the potential efficiency differences between designs.My youngest machine is 30 years old and I enjoy buying and rebuilding machines from the 40s and 50s, but I expect to spend some real cash on a DC system, so good information is key.Thanks again,Pete
You're welcome, Pete.
Re: fan size = cfm being bogus: Overall I share your viewpoint, but often the styles found in hobbyist machines don't vary a whole lot. Sometimes they do, but often they don't. There are many things that can affect the end cfm at a tool. What I've found though is that fan design (fan shape, number of blades, etc) can matter a fair amount, but so does everything else in the package. Filter media type, filter size, dust cake, blower inlet/outlet, ducting, resistance in the tool itself.
Want to see what I've been up to? Building a cyclone and running dozens of tests was just the start. Check out what some friends and I did last week to a generic 2HP dust collector. You might find it interesting. ;)
http://www.phoenixwood.ca/forum/index.php?showtopic=481
Cheers,
Allan
Pete -- I've had the 1 1/2 HP Oneida for about seven years and would do it again if there weren't better choices available -- like their new model with external bags. But, all in all, it is a major improvement over no dust control at all and my only complaint is having to clean the pleated filter inside the cyclone. It's just too hard to access and reinstall. But, for me, it has been a good system. Their new ones are better.I had Oneida design the ducting for me. The first layout was modified a couple of times until it did what I needed, but it was a good experience working with them and I had no problem buying everything from them as a turnkey package. I mounted the cyclone on a concrete block wall using their brackets and the larger collector drum (50 gallon?). I left enough room below the unit to place a wooden dolly beneath the drum so it could be rolled outside when it needed to be emptied. Since my shop has a ten-foot ceiling, height was no problem.The main ducts are mounted overhead with drops and blast gates close to the machines -- chop saw, radial arm saw, table saw, Peformax sander, spindle sander, belt/disc sander, router table, band saw, planer, and jointer. A couple of these are connected with flex hoses and don't have dedicated drops so I can move them around. When I'm using the planer or jointer, I hook up a trash-can type separater with a five-inch flex hose so the larger chips don't fill up the cyclone collector quite so fast. This works great even though the company didn't think it was necessary, but they don't have to haul the chips around, either. (The cyclone is located in a small closet at the back of the shop to keep the noise level down and hauling the collector drum around when it's full is a pain.) It's much easier to dump the trash can and the air flow is up to it. Sometimes I'll have to empty the can a couple of times before a job is done, especially if I'm using rough stock.What I notice most is the absence of fine dust floating around the shop. The system doesn't capture 100% of the dust, but mostly that's because the tools aren't really designed well to collect it. For example, even though I have an Excaliber overarm blade guard on the PM-66 saw, and both the guard and the saw are connected to the DC system, there will always be heavier dust particles left on the table after ripping somethging. That's because the saw itself leaks air all around it. Same with the 16-inch band saw, etc. But the level of airborne dust is way down and I use an overhead air cleaner if I'm sanding which helps. I think I'll add a roll-around vac for use with portable tools some day, but I do most of my ROS sanding outdoors and one more noise source ain't needed.I live in Central Florida where the temp and humidity are high most of the year, so I put in air conditioning when the shop was built and the return air filter on the A/C, which is a pleated paper one-micron filter, doesn't load up at all. I only change it a couple of times a year normally which tells me that the Oneida is doing its job. So, Pete, unless you want to spend a lot of time messing with the DC system instead of woodworking, I'd go for one of the Oneidas. Putting up the ducting will take you a couple of days anyway unless you have a very simple layout. Real world -- it works. Let me know if you want more detail. Jim
Pete,My blurb was just a summary of the conclusions for the benefit of those interested. I agree that, without the full explanation, it is wise to be skeptical. Most that have read Bill's research thoroughly, trust his methods and will be satisfied with the bottom line.I would suggest to you that you be even more skeptical of anecdotal evidence from this site concerning dust collection. We are not talking about a drill press, so the criteria for an accurate evaluation is much more complex. If you read Bill's site you will gain the expertise necessary to tell the useful from the B.S.Todd
Thanks AntzyClancyI was trying to decide how I was going to say it.
Bill has been through a lot some people have taken advantage of him he licensed them to make his cyclone design for a percentage of the profits it sounds like they may have taken advantage of him & not shared the wealth & his health is real bad due to Viet Nam & dust from wood working when he thought he was protected by home shop consumer dust collection systems. Bill has many many dollars & lots of time tied up in testing & building & all he wants to do is help protect his health & yours & my health. He has put up this site & funds it who knows how I think mostly from donations & provides vital information. Many people have built his cyclone system & all feed back I've seen on several wood working forums has been positive.
Building a cyclone is not an easy job however Bill's cyclone is still being made by Clear Vue Cyclones & the feed back on these systems has been positive also.
http://www.clearvuecyclones.com/
Remember several of the cyclones being sold now have had input from Bill but do to the costs of manufacturing & the desire to cut corners to make more money these manufactures may have short changed Bill's design so their cyclones may not have all the mods Bill's cyclone has & may not preform as well as a true complete Bill Pentz style cyclone. Yes I have been in contact with Bill by E-mail from time to time to ask questions & was always answered very courteously. I have also e-mailed others that have built his cyclone & compared answers on performance of their cyclone with answers of others that have other manufactures cyclones & the Bill Pentz design always seem to have a slight edge meaning they work better.
No I don't have a Bill Pentz cyclone my ceiling is only 7'10" which I understand isn't tall enough to erect the cyclone & still have room underneath for a chip barrel.Good, better, best never let it rest until your good is better & your better best.
OB,Check out the ClearVue Web site and give them a call. Your ceiling height can be accommodated. It turns out that you can use cyclones at an angle, or even horizontal. Doesn't sound logical, I know, but its true.Todd
Thanks Todd
I am in the process of having the electrical updated in my shop right now & will need to move a couple pieces of equipment 1 is the DC which sets in front of the power panel & the combo sander that sets in front of the DC & I suppose that there are several little items that will need to be moved so that the electrician can get in to do the job. Thank goodness I don't have to pay for this up grade. The apartment complexes that we manage are paying for it. I'll be having 4 220v plugs installed & 6 110v plugs installed with surface mounted EMT & a vent fan centrally located installed as well as 4 switched plugs on the ceiling to plug more lighting into.
I'll also have to fit the clearvue to my budget as well as the shop. It will need to be on a roll around base because it will be put right back in the same position as the current DC in front of the power panel.Good, better, best never let it rest until your good is better & your better best.
If you go to Grizzly's Cyclone page you will see that they adress this topic. In fact they seemed more than a little pi$$ed about the blantant one sidedness of their test. You should check it out.
MikePardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I am embarassed to say that I have NEVER cleaned out the upper bags on my dust collector which is attached to the panel saw and the vertical sander ! It is Sunday morning here and I am now off to the workshop to remove and clean the upper bags !!
Thank you for that tip - am sure that we will be far more dust free hereafter.
By the way do you have any ideas on a dust collecting system for a sanding table ?
Have you thought about hooking it to your newly cleaned dust collector? I do some work for a cabinet shop and it's very effective on theirs (when they remember to hook it up) !
Since the house is on fire let us warm ourselves. ~Italian Proverb
My story gets better - lol.
After cleaning the upper bag last weekend and seeing the improvement in air flow in my DC system, I recruited my wife to help with another change.
A couple of years ago, I bought some new bag fabric (five micron?) and was going to have her make a new upper bag. For some reason, that didn't get done and the fabric laid on the shelf until yesterday. She whipped out a new bag in a couple of hours and I installed it expecting to see some reduction in air flow due to the tighter weave of the new bag. I don't have a way to measure the air flow, but I don't think there was any significant loss. The "stock" bag (30 micron) "leaked" fine dust so I'll be watching to see how much the new bag reduces the leakage.
I don't have a sanding table but use 1.25" vacuum hoses to connect my sanders and biscuit joiner to a DC system port. It isn't perfect, but it definitely gets most of the sanding dust. I'm hoping that the new bag keeps most of that dust in the DC system - lol.
Edited 6/25/2006 8:51 am by Dave45
Oops, I forgot to attach the pictures.
Here is pic of the panel saw with the dust extractor on the left
Thank you Dgreen and Dave45 - I now have a much free-er flowing air through the twin upper bags - I could not beleive the amount of flour fine dust that was caked on the inside of the bags !! On the other hand , had I thought a little more , I should have realised that after sanding some 1200 meters of African Mahogany skirting boards and arcatraves last week on the vertical sander with a 100 gr belt, there should have been losts of the stuff !
I dont have a sanding table yet, but I saw a small picture somewhere which showed an obviously flat table with zilions of what appeared to be approx 12mm dia holes in it, and the sading dust sort of "fell though" these holes onto the dust receiving surface blow - now I was thinking of building one with a sort of cone shaped bottom and hooking the dust collector pipe to it - but ....., (there always is one isn't there ?), having read Dave45's article on fine dust, I am concerned if I willbe able to catch as much of this dust that I would like to. I have a Europac twin bag system ( 380 volt three phase) with 100mm ducting pipes -
Having now also cleaned the upper bags, I am considering a flter system over these upper exhaust bags - do you clever guys have any more words of wisdom for me here in South Africa ?-
We replaced the 160 filters in our bag house and American Filter Fabric recommended dumping a few pounds of flour on the initial start up to lightly coat the bags so sawdust would stick so readily.
I have the small JET one.. I will give it away... My Ridgid Shop vac works better....
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