US vs. EU method for dust collector CFM?

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jttheclockman

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Where am I disagreeing with what Bill said?? If you are referring to my first statement in post #32 I stand by it, For what you are doing. If you feel a need to jump up in size to capture more so called finner dust than do so. But AGAIN and I keep saying this then take in consideration all other factors. Dust is produced all around a power cutting and sanding tool. The dust collector captures only so much. You have to focus on the entire picture then. Because you got the state of art dust collector does not in any way mean you are collecting all dust from that tool. That is all I am saying. You throw out the number 15% more dust collect with a higher CFM what is 15% mean. Just numbers. Dirty filter, clogged pipe all numbers go out the window.
 
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Curly

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You can make a simple manometer like this youdude video shows, lots out there some better than others. Or you can spend more on a magnehelic gauge (get a used one off eBay because new they are heart stoppingly expensive). Make sure it has the range you need.



If you want to go the filter shaker route like CV have just introduced the shaker motors are cheap and would not be all that hard to make.

Pete
 

jrista

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Where am I disagreeing with what Bill said?? If you are referring to my first statement in post #32 I stand by it, For what you are doing. If you feel a need to jump up in size to capture more so called finner dust than do so. But AGAIN and I keep saying this then take in consideration all other factors. Dust is produced all around a power cutting and sanding tool. The dust collector captures only so much. You have to focus on the entire picture then. Because you got the state of art dust collector does not in any way mean you are collecting all dust from that tool. That is all I am saying. You throw out the number 15% more dust collect with a higher CFM what is 15% mean. Just numbers. Dirty filter, clogged pipe all numbers go out the window.

The 15% means fine dust IS collected, vs. not. Don't have to read more into it than that. I would also say, that some dust accumulation within the ducting isn't going to immediately negate the benefits that a properly sized DC will provide. Diminish, sure, and that diminishing will increase over time. Obviously, cleaning the system is important. I have no intention of just letting it all just remain dirty all the time, that would be ridiculous. I have no intention of leaving my dust filters clogged either. Assuming any given system would diminish in effectiveness for the same factors over time, then...the ABILITY (at all) to collect fine dust, should remain for the more capable system, while being non-existent for the less capable system. Assuming you don't let the darn thing get so clogged with dust that it loses its capability, that is.

In fact, I've been fiddling with a design for a muti-nozzle wide-angle nozzle jig configured in a ring, that I could set up around my primary filter on a rail system that would allow me to move this jig up and down over the filter. Connect it to my air compressor when I need to blow out the filter, and just slowly raise (or lower) the jig to clean the filter. You can pick up a decent duct cleaning system for $150, capable of up to 25 feet of reach, even capable of turning 45 degrees. Keeping the system clean should ensure it performs well. Dust at the periphery shouldn't be a particularly huge deal, as that's where the greatest drag is anyway. The dust and chips move through the center of the airflow. As long as you have enough FPM to prevent dust precipitation and damming, then I don't expect a film of dust buildup on the insides of the ducting to have a huge impact on performance. Not enough to negate the benefits of 1000CFM collection power at the tool in any shorter timeframe, anyway. If all this was possible, that all these other factors would just negate any benefits of a higher CFM at the tool, why would this guy, Bill Pentz, who has even engineered a more efficient cyclone, spent many years verifying the factual and scientific basis of magazine articles in the woodworking industry, dedicate such a large web site to educating woodworkers to the significant dangers of fine dust and how to collect and retain it properly?

I am honestly confused why you linked Bills site. He is pretty clear about everything. The benefits of capturing fine dust are not moot or meaningless, but you seem to be insistent now that they basically are? I honestly cannot pin you down, JT. I really don't quite understand you. You shared a valuable resource. I've been reading it. Its got a lot of sound, scientific information and resources it references. There is SCIENCE behind this. There are demonstrably some very SEVERE limitations and issues with your run of the mill DC (and have been for quite some time), such as the two or three HP Jet systems I was looking at. I'm thoroughly convinced now that neither would have come even remotely close to doing anything other than giving me the ILLUSION that I was protecting myself, given me a "clean" appearing shop, then still been exposing myself to fine wood dust that I have little question would have perpetuated my health issues over the long term (only, I'd have been quite confused as to why I was still suffering poor health effects, too, if I'd gone with the Jet units. Quite convinced of that now.) I understand the science presented about why suction power falls off so quickly, and why fine dust is not collected as easily as chips or coarse dust, presented on that site. It baffles me, why you now seem dead set to counter what Bill had to say there. :confused:
 

jttheclockman

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The 15% means fine dust IS collected, vs. not. Don't have to read more into it than that. I would also say, that some dust accumulation within the ducting isn't going to immediately negate the benefits that a properly sized DC will provide. Diminish, sure, and that diminishing will increase over time. Obviously, cleaning the system is important. I have no intention of just letting it all just remain dirty all the time, that would be ridiculous. I have no intention of leaving my dust filters clogged either. Assuming any given system would diminish in effectiveness for the same factors over time, then...the ABILITY (at all) to collect fine dust, should remain for the more capable system, while being non-existent for the less capable system. Assuming you don't let the darn thing get so clogged with dust that it loses its capability, that is.

In fact, I've been fiddling with a design for a muti-nozzle wide-angle nozzle jig configured in a ring, that I could set up around my primary filter on a rail system that would allow me to move this jig up and down over the filter. Connect it to my air compressor when I need to blow out the filter, and just slowly raise (or lower) the jig to clean the filter. You can pick up a decent duct cleaning system for $150, capable of up to 25 feet of reach, even capable of turning 45 degrees. Keeping the system clean should ensure it performs well. Dust at the periphery shouldn't be a particularly huge deal, as that's where the greatest drag is anyway. The dust and chips move through the center of the airflow. As long as you have enough FPM to prevent dust precipitation and damming, then I don't expect a film of dust buildup on the insides of the ducting to have a huge impact on performance. Not enough to negate the benefits of 1000CFM collection power at the tool in any shorter timeframe, anyway. If all this was possible, that all these other factors would just negate any benefits of a higher CFM at the tool, why would this guy, Bill Pentz, who has even engineered a more efficient cyclone, spent many years verifying the factual and scientific basis of magazine articles in the woodworking industry, dedicate such a large web site to educating woodworkers to the significant dangers of fine dust and how to collect and retain it properly?

I am honestly confused why you linked Bills site. He is pretty clear about everything. The benefits of capturing fine dust are not moot or meaningless, but you seem to be insistent now that they basically are? I honestly cannot pin you down, JT. I really don't quite understand you. You shared a valuable resource. I've been reading it. Its got a lot of sound, scientific information and resources it references. There is SCIENCE behind this. There are demonstrably some very SEVERE limitations and issues with your run of the mill DC (and have been for quite some time), such as the two or three HP Jet systems I was looking at. I'm thoroughly convinced now that neither would have come even remotely close to doing anything other than giving me the ILLUSION that I was protecting myself, given me a "clean" appearing shop, then still been exposing myself to fine wood dust that I have little question would have perpetuated my health issues over the long term (only, I'd have been quite confused as to why I was still suffering poor health effects, too, if I'd gone with the Jet units. Quite convinced of that now.) I understand the science presented about why suction power falls off so quickly, and why fine dust is not collected as easily as chips or coarse dust, presented on that site. It baffles me, why you now seem dead set to counter what Bill had to say there. :confused:
Please do not baffle yourself any more. Do what you think is right. You are doing your homework. This is good. Forget what I ever said . I do not know anything I am talking about. Just rambling. Lot more informed people here.
 

jttheclockman

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Hmm. I feel this "test" was flawed, as he only tested a small segment of PCV pipe, and without any static charge built up on it at that. When a static charge builds up on the surface of PCV, it is not the PCV that conducts...it is the built up charge itself, thanks to the electric field that charge creates, that actually conducts (once that field reaches something that can conduct it to ground).

I wish this guy had actually tested the resistance of PCV ducting that actually had static charge already built up on it. If he had, I believe his results, and the measured resistance, would have been significantly different. Draining the charge is the point...it doesn't matter that PVC itself isn't conductive.

Further, I believe to actually solve the static charge buildup problem, grounding the outside of the ducting wouldn't be very effective...you would have to ground the inside. Hence why I was wondering if anyone had an ingenious way of doing that. Your recommendation of using a static dissipating coating on the pipe is actually pretty ingenious, I have to say. If you could coat the inside of the pipe, then maybe have metal grounding points periodically...that might actually work...

https://www.bing.com/videos/search?...CE0814BB8A&view=detail&FORM=VDRVRV&ajaxhist=0

Just wanted to point out there are a ton of videos on the net that talk about grounding PVC. The thoughts of grounding both inside and outside if you truely want to ground it. It mainly for peace of mind and at times the uncomfortable shock that can cause disruption to whatever you are doing and this can become a serious issue. Many talk about grounding flex hose and the easiest way is to use metal spring like flex hose that has that metal wire in it. If using all plastic it is pretty much impossible to but sure there is some method thought of.


To address the dust collector again there are a ton of videos that show various people's setups and they give THEIR thoughts. Some maybe backed up with science and others backed up with actual use and they share their experiences. But I found one video that sort of summed up what I was trying to tell you and again it is his opinion and mine in sort of a way that the concentration on a dust collector is not the only aspect of collecting dust in a shop. Dust collectors are designed for the large tools in the shop such as jointers, tablesaw, bandsaws and such. They move large volumes of air to collect larger chips and debris and you found with your reading that some DC have the ability to collect smaller dust particles but again are limited. The better DC are more expensive. Won't go into all the other things that go along with figuring which unit is best for your needs you are doing that. But as mentioned in that one video it is best to use a shop vac or single stage DC to directly collect the dust from smaller tools such as sanders weather drum sanders or palm sanders. Dust collectors fail doing a good job in this area because you need to decrease the size of hose running to them. Now you defeat the DC main objective. Collecting dust at the source is the best way to combat the small dangerous dust particles thrown in the air. That seems to be your main objective. Talking dust needs to be controlled at the very source such as the blade, the sanding pad and so on. So just because you set up a dust collector at the outlet the manufactorer supplies does not mean the unit is enclosed enough to keep dust from escaping as well as if you use a tablesaw the dust coming off the top of the blade is as dangerous as the dust coming off the bottom. Lot more to think about when setting up a shop. Look at all your tools that you want to connect to DC and see if they are enclosed enough to capture all that dust. Even a cabinet tablesaw is not enclosed enough.
 

MRDucks2

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In one of my shops I laid out metal ductwork to connect my 4 larger tools/dust generators simultaneously to the collector using gates to control the flow.

I realized in a one person shop I never used more than one tool at a time and they were all in close enough proximity that it made more sense for me to look at maximizing vacuum and flow at the individual tool and hook them up one at a time as needed. I am not a production worker, tend to work in batches at a single tool before moving on to the next and I am in no particular hurry.
 

jrista

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To address the dust collector again there are a ton of videos that show various people's setups and they give THEIR thoughts. Some maybe backed up with science and others backed up with actual use and they share their experiences. But I found one video that sort of summed up what I was trying to tell you and again it is his opinion and mine in sort of a way that the concentration on a dust collector is not the only aspect of collecting dust in a shop. Dust collectors are designed for the large tools in the shop such as jointers, tablesaw, bandsaws and such. They move large volumes of air to collect larger chips and debris and you found with your reading that some DC have the ability to collect smaller dust particles but again are limited. The better DC are more expensive. Won't go into all the other things that go along with figuring which unit is best for your needs you are doing that. But as mentioned in that one video it is best to use a shop vac or single stage DC to directly collect the dust from smaller tools such as sanders weather drum sanders or palm sanders. Dust collectors fail doing a good job in this area because you need to decrease the size of hose running to them. Now you defeat the DC main objective. Collecting dust at the source is the best way to combat the small dangerous dust particles thrown in the air. That seems to be your main objective. Talking dust needs to be controlled at the very source such as the blade, the sanding pad and so on. So just because you set up a dust collector at the outlet the manufactorer supplies does not mean the unit is enclosed enough to keep dust from escaping as well as if you use a tablesaw the dust coming off the top of the blade is as dangerous as the dust coming off the bottom. Lot more to think about when setting up a shop. Look at all your tools that you want to connect to DC and see if they are enclosed enough to capture all that dust. Even a cabinet tablesaw is not enclosed enough.
Have you read Bill's site? Just wondering if you've read it recently or not, as it covers all of these things... Hood design, capture points, airflow at each capture point, etc. etc. etc. to make sure you are indeed capturing as much dust as you can.

No, it is not perfect. But if you get enough airflow at the right capture points for each type of machine, then you'll capture most of it. Bill's entire site is about capturing fine dust, so that your small personal woodshop could pass an EPA inspection (something most small woodshops, certainly mine right now given I don't even have a DC yet, do NOT pass, even when they appear to be pristine clean, given the stringency of EPA's requirements.)

You keep telling me its hard. Sure. It's hard. But, its also all covered on Bill's site. His entire goal, is to help small shop owners collect FINE dust, the dangerous and deadly dust (over a lifetime of exposure, which is RADICALLY high for most small shop owners), the invisible (without magnification) stuff, 10 microns and smaller, but particularly the stuff that gets deep into our lungs and even bloodstreams, 2.5 microns down to 0.2 microns.

You keep telling me its hard, and you have to address all these factors. Bill covers ALL of it... If you haven't read his site recently, you should. Its extremely thourough. Neither the 2HP nor the 3HP jet, would get the job done. Even with an upgraded filter for "fine" dust capture (which generally stops at around 0.5 microns, if it even gets below 1 micron, and is often not even 99% capture), neither machine is even close to powerful enough to capture anything more than chips and coarse dust. This is the really sad thing I now understand about the average mainstream DC, especially those with a cyclone. They are underpowered. Bill has a section of his site where he covers the amount of air a 12" impeller (most commonly used on units up to 3HP) can actually move. Turns out, a 12" impeller on a 3/4HP motor will move just about as much as an impeller that size can. Increasing the motor power won't increase the airflow much, if at all. My original question about US vs. EU "methods", is basically a way manufacturers have gotten around issues in the past where they were rating their units only unfiltered, which delivers about twice the real-world performance, if not more (depends on specific design attributes). Problem is, even the US method (i.e. ~1200CFM for the Jet 3HP unit), doesn't properly account for the losses due to the cyclone's vortex. Minimum viable cyclone DC motor power should be 5HP, and should use an impeller larger than 12" to ensure they are actually moving enough air...but you get into really expensive territory at that level...$5000 and up. (FWIW, the CV is ~$3200, and is capable of moving at least as much dust as a much more expensive 5HP or larger cyclone from common competitors, even Oneida.)

You should really re-read the site. Its quite thorough and extensive, and I think you'll find it covers the things you are trying to warn me about. I'd been there before, one page here or there. But I'd never read the entire thing through and through. Certainly not re-read any portion of it. Now that I'm reading every word, all the questions I've had about dust collection are answered quite clearly there. He covers hood designs and capture location(s) (there may in fact need to be two or more), etc. And the entire, fundamental purpose of his site, it to make sure readers end up with the knowledge to collect the find dust that gets deep into our lungs and nasal/sinus passages and wreaks so much havoc.

I had never even considered just how much silica is in wood dust, that cutting wood with say a tablesaw, when viewed in the dark, would create sparks as a result of that silica, or just how the silica creates these NASTY sharp, pronged fragments of fine dust that can permanently embed them in our lung tissues, or wreak other havoc if they get absorbed into our bloodstream. All because of the silica in wood dust. This is the dust that a conventional DC, that simply cannot move enough air from each capture point because, even at 3HP or so due to frequently undersized impellers (especially when talking about a cyclone system), will not capture well. He has mentioned the figure, 15% "at least" or "or more" many times throughout his site. This is the uncaptured fine dust that is only captured when the airflow is high enough, and also capturing from enough points around the point of dust creation.

For example, with a table saw, you need to capture from more than one point to capture it all, such as back/bottom and top. The TOTAL airflow, from all capture points combined, must total close to 1000CFM. With smaller inlets, yes, you are limited in how much CFM you can capture at a given air speed (i.e. 4000FPM...which is an industry standard, but also only for the airflow in your horizontal main lines...it is insufficient for either vertical ducts, or for proper capture volume at the source(s)). However, in the example of a table saw, his recommendations are to capture at about 550CFM from the back/bottom, and 450CFM from the top, resulting in a grand total amount of collection capacity at 1000CFM. This is his recommended MINIMUM capture volume, FWIW...further, he recommends MODIFYING stock capture ports and rigging up custom capture points to maximize where we capture and how much fine dust we are able to capture. Another potential option is to just move more air...higher air velocity will move more CFM at the point of capture, which may not require modifying the ports on any given machine.

CFMRequirementsTableSmAAF.gif


So, you are correct, most tools ARE insufficiently ported and enclosed! But, Bill covers all of this on his site, in rather great detail. The table above shows OSHA, which is insufficient, and medically recommended airflow rates for various machines. Note how all are generally around 1000CFM, give or take. Some things are more forgiving, such as a drill press (which still creates plenty of fine dust, but the DC isn't having to overcome the velocity of dust generated off of say a high speed spinning saw blade, which will off the blade move dust and chips up to 9000FPM or so!!) For my bandsaw, I may need to modify my ports. Bill recommends ~438CFM from two ports on each bandsaw, and recommends at most two bandsaws per shop. Whether a 4" port will work, depends on whether I can get enough airflow at that device for a 4" port to work. Remember, CFM is relative to BOTH port area, AND air velocity. A 4" port is insufficient ONLY if you assume that the velocity is just 4000FPM. At 5000FPM, airflow through a 4" port jumps to 436CFM, nearly dead on for Bill's recommendation to sufficiently capture the chips and dust made and capture fine dust. I am also of a mind to include another duct that I can put on an adjustable boom or something, to capture the dust coming right off the piece of wood as I'm cutting with the bandsaw as well. These are all things that will govern what DC I get, to make sure I have enough airflow to do what I need and want to do, from the number of inlets at each machine that I end up deeming necessary to capture the fine dust.

John, I don't have any illusions that this is "easy"... You linked me in one of your first posts the best resource there is, I think, on this subject. Reading this site is informing me of what I'll need to do, to capture the fine dust. I've suffered plenty from dust and CA fumes. I know that it takes a very minor exposure, to set off my allergic reactions to these things. Once set off, it can be weeks before I am back to "normal" (which in the past, was actually still rather stuffed up and miserable), and if I'm constantly getting exposed (with as much dust as is settled in my workshop right now, its pretty much guaranteed I will be), then I'm miserable on a continual basis. I may have to modify ports, tighten up enclosures, jury-rig enclosures for things like my lathes. Fine. I enjoy a lot of that stuff anyway. Bill has plenty of resources on his site about what is necessary here, to actually capture the fine dust enough so that a small shop like mine, could pass an EPA test. That is going to be FAR cleaner than the average woodshop, and should be clean enough to meet my goal of no longer suffering because of this hateful crap floating around the air of my home. I don't need to be told its hard. I know its hard. But I'm determined.
 
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jrista

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In one of my shops I laid out metal ductwork to connect my 4 larger tools/dust generators simultaneously to the collector using gates to control the flow.

I realized in a one person shop I never used more than one tool at a time and they were all in close enough proximity that it made more sense for me to look at maximizing vacuum and flow at the individual tool and hook them up one at a time as needed. I am not a production worker, tend to work in batches at a single tool before moving on to the next and I am in no particular hurry.

Yeah, this was something else Bill Pentz site covered. That many small shop owners take their cues from large commercial shops and their mainline designs, which usually start out quite large (10" or more even), then eventually peter off down to around 4-6". The average small shop owner should just use the DC's maximum duct diameter through and through, to each machine, then drop down to smaller ducting as necessary for each machine, since for small shops it is rare that more than one machine would be on at once. Sounds like you chose the right path for your shop.

I am curious, do you know what your air velocity is? I'm learning here that, for fine dust collection, it needs to be more than the most commonly stated 4000FPM. In fact, for my needs, it is likely going to need to be around 5200FPM or so, and unless I want to modify ports on many machines, I may need even more than that. CFM is commonly stated for various duct/port sizes at 4000FPM, but it can be increased with a higher air velocity, even for smaller ports.
 

Curly

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When you get to reading the Aussie forum I linked earlier you will come across at least one thread where they found 3 ports (4" each) on a bandsaw were best. One under the table at the lower blade guard, one at the bottom of the lower cabinet and the third placed just above and behind the upper blade guides.
 

jttheclockman

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OK Jon, seems Bill is your Guru. No I never read through his site as you have. His writings were not around when I built mine and I have nothing like what you are attempting I have a contractors saw and an open base bandsaw. None of my tools would pass his recomendations. I used articles from Wood magazine, Fine Woodworking and from Delta itself and was a member of many woodworking forums when I started some 45 years+ ago. My biggest dust maker in my shop has been and still is a scrollsaw. I am down to 3 of them. They are one of the hardest tools to collect dust from. Many people have tried and if they have something it involves many pipes encircling the top and bottom of the table and sucked up with a shop vac. Dust collector would do no good on a tool like that. I could not listen to a shop vac for hours on end for I spent thousands of hours behind them over the years. So I approached my shop in a different way. I use a DC to collect large particles at those machines that produce them. I use a shop vac at my sanders, and let the dust fall on the floor at my scrollsaws and clean up after each cutting. I have a air cleaner that I maintain well. I always wear a dust mask when in my shop. I do not suffer from dust problems as you do. I have clean clear lungs because I have had many chest xrays. and cat scans especially this past year because I am going for surgery for other problems. I thought I would mention this because you would probably bring it up. My line of work for 45 years took me in places far more dangerous from contaminants than a shop full of wood dust. I survived those.

I will not involve myself any more in this thread. Seems you know what you need to do and understand what is needed. If those articles are helping you make the decisions than they are valuable. and hope you succeed in your quest. Having a safe working environment is needed. Enjoy and have fun in the build.
 

jrista

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I always wear a dust mask when in my shop. I do not suffer from dust problems as you do. I have clean clear lungs because I have had many chest xrays. and cat scans especially this past year because I am going for surgery for other problems. I thought I would mention this because you would probably bring it up. My line of work for 45 years took me in places far more dangerous from contaminants than a shop full of wood dust. I survived those.

I'm glad you've managed to avoid any issues. That is lucky. I'm honestly very glad you haven't suffered any issues. I honestly would not wish my experiences on anyone. That said, I honestly wonder how many people have issues, without realizing it. I've been told I'm "fine", when I go in for lung testing and the like...but, experientially, I have not been.

I have had problems, and the sheer severity of them was not clear to me, until recently. Due to a number of things, I turned some the beginning of 2022, then didn't turn again until late nov/dec just for a set of 12 pens, and then haven't turned since. The time off, largely out of the shop the vast majority of the time, has given me a new perspective of what it is like to actually breathe. My entire life, I've had allergies to many things. My breathing has never been good. Starting in 2020, due to starting my journey into woodworking that year, I discovered I had some kind of severe allergy (turned out my most severe of all is to CA glue fumes, but dust is an issue as well). Near-anaphylactic. I started allergy shots in fall 2020, and now in 2023, they have actually had an impact.

I've never breathed well, in my life. For the first time, in maybe the last 6-9 months, I actually AM...and its...its astonishing what its like. I am a "mouth breather", by necessity, because my nose, as long as I can remember back into my childhood, has never worked before. I have had to breathe through my mouth to get any air most of my lift. My nose finally does work now, and...its so amazing. To be able to actually breathe... I'm able to smell. These things, crazy as it sounds, are relatively new to me, maybe just within the last year. I had no idea, just how badly I was suffering, until...I wasn't. I honestly wonder how many other people are the same...suffering, without knowing it...

I haven't been surviving. So much of my life has been miserable, because I'm always having to work hard, just to get air. I was naive, totally naive, when I started this thread. Thanks you you and Pete, I no longer am. Further, I actually honestly, truly have hope that I can properly manage the dust issue that is still plaguing me, and make sure I don't have to suffer from it any more. That, truly, is hugely important for me. So, for that, for sharing the link to Bill's site, thanks.

He is a bit of guru I guess, but I've also been doing my own independent research to verify some of what he states, as at first I was skeptical (I mean, EVERYONE quotes the "chip collection" CFM requirements, for an air velocity of 4000FPM...its SO prolific). I just had no clue, before reading that site. I agree with you, BTW, that a shop vac is better for some machines. I guess ironically, so does Bill! ;P You linked a very thorough resource. He actually agrees with you on most points, and covers solutions to them (all, as far as I know, although I haven't read the entire site just yet.) I have no intention of reducing my ducting to say the 1.25 or 2.5 inches required for some machines. My miter saw has a 1.25" port, and I've always used a shop vac with it. In fact, once I get a proper DC, the better quality shop vac (combined with the little bucket cyclone system I have for that) will actually be freed up to be carted around the shop, making it a heck of a lot easier to use where its the more appropriate tool.

Anyway. I started out with this thread totally naive. I'm ending up here, fairly well educated now. I am glad that I will be able to make a much more informed decision that should actually have a positive impact to my life as a woodworker. If I hadn't ever started this thread...well, I'd probably have a woefully insufficient Jet 2HP Cyclone right now, and I am 99.999% sure I'd still be sucking down dust 2.5 microns and smaller. So thanks.
 

jrista

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When you get to reading the Aussie forum I linked earlier you will come across at least one thread where they found 3 ports (4" each) on a bandsaw were best. One under the table at the lower blade guard, one at the bottom of the lower cabinet and the third placed just above and behind the upper blade guides.
Yeah, I've come across a couple of videos now, where people have cut that third port in the lower cabinet. My Jet bandsaw actually has two ports, I think right where you've mentioned. I'm a bit wary of cutting into the lower door, in all honesty...but, I guess, as long as I can figure out a way to do it without it looking like a hackjob, I probably will. I suspect even with good airflow and the two ports I have, I'm likely still going to have dust ending up in the bottom of that lower cabinet. From the videos I've seen, putting a port near the bottom center there, almost entirely takes care of that problem (I suspect most didn't actually have the airflow...most seemed to have your mainstream 2-3HP Jet, Laguna, Powermatic, Grizzly, etc. DC system. Many in fact, were not cyclones, and I think even may have been the scary "bag" collectors that only filter dust down to 20-30 microns!!)
 
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