Cyclone plus Dust Collector

[Ken in Regina]

That Belfab thread was getting way too long so here's a new one.

Bob and Allan both touched on something that intrigues me and seems to make so much obvious sense that I'm surprised neither one expanded on it. So I'll ask the rather obvious question here. It starts with something Bob said:

"A cyclone has three parts. The pre-separator, the blower, and the filter. Adding the preseparator to the single stage, is exactly the same thing. You can make it as 'efficient' as you want. "

So, the obvious question is: can we use the Bill Pentz design for the cyclone body, sit it on top of a drum and connect the Belfab for suction? Would the basic cyclone body design work or would it need some modification? If modified, how?

[Allan Johanson - South Su]

Yup...but now you've essentially spent over $800 on a blower and filter bag (Belfab JJ) when you can get better performance for less cash with Bill's monster blower idea. :)

Allan

[Allan Johanson - South Su]

http://www.mgsweb.com/woodworking/cyclone/cyclone.htm

The question I have for Bob or anyone else who may have actually done some real testing on these things, is what is the SP cost and real particle separation efficiency of various styles of preseparators for a traditional single-stage DC?

- Basic trashcan setup
- Refined "trashcan"
- Basic cyclone line the WOOD one in the link above
- Efficient cyclone like Bill's

All the four above mentioned versions have different SP costs and different particle separation rates. Does anyone have any idea what they really are?

I'm a huge fan of a preseparator to help reduce the amount of dust hitting the filter media. Even if I had a single stage DC with a large Beane bag, it will still underperform after a period of time as dust particles get embedded in the fabric. Shaking the bag may not free these particles. Efficiency will go down along with the performance.

The key is reducing the amount of dust that the filter is exposed to. The key is a preseparator.

But I'll also propose that when you stuff a preseparator in front of a Belfab JJ that is as good as Bill's cyclone is at particle separation, the performance will go down. No longer will you be getting 1080cfm at whatever SP....it'll be a chunk less.

Allan

[Bob, in Lachute, Qc.]

OMG Allan,

Lesssssssssssss Money????????????????????????????

Hmmmm, now where did I see someone post, that to date, his cyclone cost $1,800 Canadian???????????Lol.

Ken, of course you can. You can use a blower to make a push-through design as well. Whatever suits your needs.

http://www.kraemertool.com/smportcyc.htm

Personally, I would consider it a total waste of time and money. Think about it for a sec. If you read "Dave' in Acton's "Pic" Post, he said that just using his simple barrel pre-separator, he only had about a cup worth of shavings in his bags, and that was , as he said, most likely due to the fact that he let the barrel get too full.

There's really no practical point , as far as I'm concerned. For the tiny preseparation gain, you'd trade-off airflow. A cup of dust,,, a few tablespoons,,, Pointless.

Simply not worth the expense. Just a barrel, and properly balanced inlet/outlet will do just fine, and cost peanuts. Have no barrel??,,,, make a simple box. Doesn't have to be round. Splurge,,, add casters, ;-)).

For me, the important details are these.
1. 1080 cfm
2. 0.5 micron filtration
3. 7 feet tall
4. 800 bucks

All the best, Bob

[Bob, in Lachute, Qc.]

Allan,

The figures I've seen for virtually any cyclone, range from 4"-4.5" SP, and that's the better ones. As you know from WoodMagazines cyclone Test, the small Penn State, only managed 450 cfm, at a paltry 1" SP. I have NOOO idea how much resistance that cyclone has, but it must be well over 6". Would have to be, to get that low a flow, with a 12" impeller. A 1 hp KING, would do as good.

Terry Hatfield, did a lot of experimenting with his cyclone. He managed to get the resistance down to somewhere over 1.5" if I recall, but he also said that it was at the expense of pre-separation.

Striking a balance, is the important consideration.

In your case, using those cartridges necessitates having high efficiency pre-separation, or the filters will clog. With the needle-felts, that not as much of a problem. Just a quick shake, and you're off again.

Bob ;-))

[Allan Johanson - South Su]

C'mon Bob....be fair. The majority of folks building the entire 14" impeller Bill Pentz cyclone are NOT spending $1800. The real number for people doing it all themselves is closer to $1000. The more they source out the work, the more expensive it'll get.

Be fair. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

[Allan Johanson - South Su]

Bob wrote:

"In your case, using those cartridges necessitates having high efficiency pre-separation, or the filters will clog. With the needle-felts, that not as much of a problem. Just a quick shake, and you're off again."

Yup (to a point). That's also why many industry situations call for bags because of the tremendous amount of crap that comes out of their cyclones and other DC units. So every time you post you never see cartridge filters being used in industry....that's when I say to myself, "Duh! Those systems typically spew out so much junk they MUST use bags!"

Ya gotta be fair when you make statements like that. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

This stuff is cool. Folks are getting educated with the pros/cons of various systems and when a particular filter media type should be used.

If I had an inefficient cyclone design that spewed out a fair amount of dust, I'd be looking at a wide-pleat cartridge filter or a quality bag. If the amount of dust was excessive from my point of view, I'd be buying a Beane bag pronto.

That's also why I strongly dislike sticking a cartridge filter on top of a single stage DC unit. Too much exposure to dust.

My personal belief is that a "quick shake" as you put it may not be enough to free up enough particles to restore a bag to full efficiency. I believe that over time the quality of filtering and overall performance will degrade. Sure, at some point you will notice it and will wash the bag, but in the meantime your system cfm performance has dropped and particle filtration isn't what you want. The end result will be more dust floating in the air and going in your lungs.

That's why I dislike single stage DC units without a preseperator.

I know the Belfab is a good single stage unit. But when you add on a preseparator, it isn't 1080cfm anymore. I don't know what it would be. It would depend on which preseparator you chose.

*******

Issue #2: SP specs for preseperators

Bill's design is very efficient and the resistance is quite low.

I'm getting 1700cfm @ 2.6" SP with an 8" duct. I can't remember the length of it....something like 8 feet of 8" duct with a 90 deg and an 8x8x8 wye on the end.

The WOOD cyclone isn't very efficient and has higher SP values probably in the 4.5" range.

I think trashcans are around 2.5" or so. Not sure.

Time to hit the sack.....gotta get up early tomorrow.

Cheers,

Allan

[Bob, in Lachute, Qc.]

Well Allan,

How much are the filters??? I thought someone said $104 each. Add the Leeson $345,,, $260. for the Sheldon Fan-wheel. That's alone is $813. Add the tax($122)=$935. Add the various individual component shipping costs, already got to be well over $1,000 right there, and you still have no sheet-metal, no blower, no switch,no wire, no plug. And, since that motor doesn't include thermal overload protection, that would be a $75 option. I called Leeson.

I can see someone saving money, using the Jet impeller ($100 Can./ $67 US) Maybe a reconditioned 3hp single phase motor, but you'd be amazed how expensive those can be, and how hard to find "used". Triple-phase is everywhere, single-phase, good luck.

Might be able to save money with a good needle-felt bag, too. All the industrial guys use those, so why not??? Since the preseparation is sooooo good, even YOU shouldn't have an issue with that,lol.

Once you have the components, how long from "concept", to functioning dc???1 month?? 6 months??

I think Garrett was smart getting his done. didn't cost a bundle, and looks like a first-class job to me. I'm also very impressed with the Job Ed in Leaside, Jim shaver, and the boys did. Very nice set-ups. For a few others though, it appeared to be a bit of a struggle.

I liked the look of yours too by the way. The "black" really looked nice. Good job.

As I said earlier, I'll probably clone the model 16 Torit-Donaldson, but that's a "when I got the time, and extra dough" project. The impeller alone, will probably cost well over $300. Should be a fun project. Pulls 1200 cfm, through a 6" inlet. 84" tall.

I even thought of trying Farr's design, using two small-bodied cyclones, mounted side-by-side, and served by one blower. Those use 12" diameter bodies, and are very short.

The smallest cyclone I've seen, other than the "cyclone in a jar", was a "Dust-Kop" push-through unit. Was a box, about 3' tall. Had a 4" inlet,a 7-8" fan-wheel, with a really wierd design. That "pushed" to a tiny cyclone, maybe 24" tall, cone included. That emptied into a dust-drawer, at the bottom of the dc. Air was filtered through a layer of insulation, in the top cavity of the box.

A friend of mine has it. I'll try to get some pics.

All the best, Bob

Here's the "Cyclone In A Jar"
http://www.mgsweb.com/woodworking/cyclone/minicyclone.htm

[Bob, in Lachute, Qc.]

Lol Allan,

You make me laugh, to hear you say that a $4000 Torit-Donaldson cyclone "Spews crap" as you said, is ABSOLUTELY ludicrous. You GOTTA be kidding me. Do you DREAM these things, or is that what you WANT it to be?????ROFLMAO

Bill's cyclone, is a Farr clone. Take a peek. To hear you talk, there is nothing out there that can remotely touch it, pre-separation-wise, ROFL. Gimme a break. Even Bill must be laughing at that one. He's the first guy to state that his cone-length is a compromise, to accomodate ceiling height. He said it right here. Talked about a 3xD cone, compromised to 1.67xD. Did i dream that?????

Allan, you know as well as I do, that a cyclone, and ANY dc, is a "variable speed" device. Each duct branch, will present it's own unique resistance, and therefore the inlet velocity will be different from branch to branch.

Also, the various densities of material, such as planer shavings, vs sanding dust, all affect pre-separator behavoiur differently.

You might convince a "Newbie" about that cyclone's "unique" preseparation, but not this old turkey.

As for your dc, are you ging to use just a short duct, 8" in diameter???? With that low of an SP rating, you're gonna have to. Just the entry loss alone is 1" SP. That leaves 1.6" for pipe. If you neck it down, you'll get the higher SP, but that 1700 cfm sure will drop.

Terry's cyclone pulled roughly 1400 cfm through a length of 6" pipe if I recall, but that was after he lowered the inner resistance to around 1.5". As he said, it was at the cost of pre-separation. Can't remember his exact numbers, but ranged from 1200-1400cfm posibly, I may be off there. He told me that last year sometime. Maybe he could clarify.

Anyway, if you wanna discuss this in private, just send me an e-mail. I think I've got a lil' "trick" to raise that SP. I expected that result, when you originally posted your blower proportions, last winter.

All the best, Bob

[Art Mulder in London]

Ken is right, that thread was getting huge.

However, I would like to publicly thank Allan an Bob for (a) the huge amount of solid information being that they keep presenting, and more importantly (b) Setting an incredible example with how they continue to disagree with each other on many points *politely*. Gentlemen, I thank you!

I have a question also about a preseparator for a Belfab. I saw the photo from "Dave in Acton" in the monster thread below, and I would just like to have some clarification. Is the photo all we need, or is there something on the inside of that preseparator (baffle, or piple elbow, or some such) that helps it do the job?

Thanks again.

[Bryan in Woodstock]

When I get a break in WW orders, I'm going to make a metal cyclone to go with my 4 bag collector. I have been in the shop a year and have been using a quickie cyclone made from plastic garbage cans and 6" hvac fittings. I know the outlet is supposed to be bigger (8") than the inlet so the air slows down so the dust can drop out of the air stream . For using 2 plastic garbage cans back to back, held together with duct tape, it's amazing how well it works as a pre-separator. I have seen factory made ones but they where $700 at the local WW store I frequent. A lot of $ for a tin can, LOL.

[Allan Johanson - South Su]

Hey Bob,

Your prices were a little high IIRC. The motor was $348 - tax included. I didn't pay the $75 for the manual thermal button thing. This motor will be jogging along - NEVER fully taxed or under any strain in my situation. The Sheldon fan was $220 - tax included also. The Farr filter I just bought was around $86 - tax included.

$348 + $220 + $86 = $654 with 1 filter. Having two filters is optional, but as Steve Cater has proven, is not mandatory.

Onto that $654, add $50 for sheet metal and another $50 for a sheet of plywood.

Now we're at $754. Add on some money for electrical. A short length of heavy wire, plug choice is optional and can vary in price, the contactor I bought was $30 or so. Since you want to compare a basic Bill Pentz cyclone to a Belfab JJ, leave out the remote control feature - or else add it onto the price of the Belfab (to be fair).

So...we're at $754 + what...maybe $46 tax included for a basic NON-remote control switch setup (120V actuated contactor with a basic wall switch hooked up to it and the unit in a proper NEMA box).

$800 TOTAL, tax included for a bare-bones Bill Pentz cyclone that will outperform the Belfab JJ.

...assuming your time isn't worth anything. But hey, we all like to build stuff - that's why we're involved in hobbies like this. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

The reason I say about $1000 for the full-blown cyclone was because in my case I'm running two filters and I paid Ed's friend $110 for wooden blower plates CNC routed to save me some time and frustration. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Each person will do something a little different re: mounting the cyclone, misc hardware, little scraps of this and that...so the ultimate price for each person will vary a bit. But the minimum you'll be spending is the $800 I listed above and it'll go up from there depending on so many things. I'll still stick to my $1000 estimate. Some folks will do it cheaper, some a little more expensive.

Cheers,

Allan

[Allan Johanson - South Su]

...because when I wrote:

"That's also why many industry situations call for bags because of the tremendous amount of crap that comes out of their cyclones and other DC units."

Somehow you read I said a specific Torit unit spewed crap.

"MANY" does not equal "ALL" http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Hey Bob....how about this thought: Whenever I make a general statement to illustrate a common thread of behaviour, please don't assume I'm dissing your favourite machines and start bringing up a specific example to illustrate how wrong I am. Because I'm not dissing your babies. I think they're cool too. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

As far as my 1700cfm @ 2.6" SP measurement goes, I provided that as an example for you to compare to the Penn State that was what....450cfm @ 1" or so? Can't remember.

Anyhow, I've done other tests with long, restricted runs with plenty of flex hose on both parts of the wye and watched the cfm drop down to as low as 1100 in some cases. I don't have the numbers here right now. They're in my shop somewhere.

I haven't actually measured the SP drop across the cyclone itself. How would you like me to measure that? I'm not sure what others are doing exactly.

Shall I buy a couple static pressure tips and place one near the cyclone inlet and another just past the blower outlet (before the filters) and hook up the Magnehelic gauge between the two tips?

What would you like me to do?

Allan

[Allan Johanson - South Su]

You're welcome, Art. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Bob and I don't really disagree about much at all. We fundamentally agree on this DC stuff from start to finish. We may not see eye to eye on the effects on a system considering a specific change or modification, but overall we'd agree. He's just a super passionate guy and if what you say can even remotely be interpreted as an attack on one of his babies, then you're in for a lashing! http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

All in good fun though. If Bob and I were sitting together in a room somewhere and I made some statement about a Torit cyclone and how they are crap and spew stuff all over my Dad's car when he's at his work (a woodshop is two doors down and a cyclone does indeed spew crap over everyone's cars) then he'd go on a rampage and you know what I'd be doing then?

I'd be grinning from ear to ear and I'd reach over and "clink" my beer bottle against his and burst out laughing. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Cheers,

Allan

[Mike Harris, London]

Hi All

For those that can't afford those expensive cyclones, I've found this inexpensive pre separator to work very well. It's much like Bryan's, Wally in Calgary and Bill Young use it as well.

I made the separator for less than the cost of the LV cyclone lid and it works much better. I empty the can 4 times before filling the bag of the DC.

Pre separator

http://www.woodshopphotos.com/albums/Mike-Harriss-Woodworking-Stuff/DSCF0123.jpg

http://www.woodshopphotos.com/albums/Mike-Harriss-Woodworking-Stuff/DSCF0066.jpg

This is a bare bones system that will do the job and for many home hobbiest it is all they need.

Allen and Bob, you're disscusions on DC systems is very educational and much appreciated but sometimes I think Newbies and weekend warriors may get scared off because they start thinking that's what they need when something as simple as this separator will meet they're needs and then some. It also works well in a network. I have it connected to about 90' of pipe and 9 blast gates, it may not be as efficent as a true cyclone but it works. And that is what many are looking for.

One day I may look at a true cyclone but it's not on must do list, this system works just fine.

Respectfully
Mike

[Bob, in Lachute, Qc.]

Good Morning Allan,

First of all, it was not I, who wanted to compare the two dc's. I hadn't said a word. You were the one who opened the subject. I just get the feeling you wanna knock that dc for some reason, yet I can't imagine why. All I did, was respond.

The Sheldon impeller is $265, according to their site.

http://www.sheldonsengineering.com/html/BillPCDN.html

Didn't Garrett say his cost him $1,800. ??????

I also saw some posts that said the filter was $104. Oh well.

Just to set the record straight, I didn't say a word, to knock the cyclones, but I did defend the Belfab. I don't know why there's this "Need" to try to put that dc down, and it's only coming from a very few of the cyclone guys.

I've never once said it is "Better" than a cyclone, even though it IS a hell of a lot better than MANY cyclones. Just read the WoodMagazine cyclone test. The results are there, in black and white.

I also find it funny, that the criticisms come from people who have never even seen one, and presenting "Theoretical" arguments about it's performance. Those arguments, always place the Belfab, in a disadvantaged position, and place the cyclones, at PEAK efficiency, lol.

Just talk to the guys that own one. Ask them if THEY'RE happy. I'm sure it won't satisfy everyone, especially if they're using a very restrictive network. That goes for ANY dc, even MORE so with a comparitive cyclone.

The fact that the criticisms come from individuals with 5hp cyclones, with 14" impellers, speaks for itself. Why worry about a li'l ole single-stage, with a 12 1/2" impeller, and a 2 hp motor, lol.

As I've said MANY times, I'd have built Bill's cyclone too, if I'd have come along when you guys were starting up. Woulda been a great project, as far as I'm concerned.

I also like the Kraemers, the Spec-Aire, the Torit's, and even the Oneida's, considering price. I'm not "Rivetted" to the Belfab. I even praised Delta's new dc's. Although I have yet to actually see one, there is every reason to believe these will be excellant performers.

As I've said, MANY times before, Any dc, that can put 800 cfm capability , at the end of a 6" duct, will get the dust to the dc. THAT, would even include some of the Asians. I'd be willing to bet the General International 2hp, with two filter bags, could easily do it. Wanna bet????

We know from American Woodworkers test, that even the 1 1/2 hp Delta 850, original version, could pull 895 cfm. The results are there in black and white. Mind you, that doesn't allow much network headroom. Just a short run of pipe.

The old Jet 2hp, that had all 6" porting, twin 1 micron bags, and a 12" impeller, pulled over 1,000 cfm. That was also in that test.

The Belfab is what it is. A 2hp dc, that will meet the needs of almost any homeshop. It does so with top-tier components. Fit's under a 7' celing, is single phase, and has a bullet-proof motor. Filtration is as good as it gets, and it's "Plug N Play". Up and running within an hour of getting it home.

It doesn't make outrageous claims, It uses 6" pipe, and THAT will handle ANY homeshop machine. It's not any better than a Kraemer E-21, but it's half the price. The Kraemer's 10 ft tall, and triple phase.

All the best, Bob

[Garrett in Victoria]

My cyclone costs were:

Motor, Impeller, and Housing - $680
Cyclone (fabricated by a local shop) - $385
2 Camfill Farr Cartridge Filters - $152
Stand and barrel – scavenged,no cost
Miscellaneous materials - $45
Electrical (plug set, contactor & remote) - $156

All in except ducting: $1,418

I might have been able to knock a little off that total with even more patience and careful shopping, but not much.

Moreover, anyone installing any dust collection system in an average shop should understand up front thhat there's far mmore labour in the ducting than in the cyclone, and the costs for the ducting materials are not insignificant.

Would I build another cyclone? Probably not, but only because in the past few months any number of new, attractively priced commercial options have presented themselves, several of which are probably adequate and possibly as good as the Pentz which is performing wonderfully for me.

Would I install bags as Bob suggests? Absolutely not. While I have no argument with his contention that needle felt bags are efficient filters, bags are an absolute PITA to empty and maintain.

I had a large 4-bag (1 micron needle felt) Delta 3 HP DC. I hated having to remove those bags, and it was impossible to not create a dust storm in the process. The barrel / cartridge filter combo is just too easy to maintain and empty to go back.

Cheers, Garrett

[Allan Johanson - South Su]

WOW...you're reading way more "criticism" then I am! Seriously!

Let's move on.

Sheldon sure jacked up the price of their fan. I believe it's a new design compared to what I have, but our original price was $190 + taxes for a total of $218.50.

Add on a few more bucks to the cyclone price then if someone wants to build the 14" fan version. But they don't have to. They can build what they want. A smaller fan, smaller motor, simpler wiring all goes to save cash if someone wants to do that.

Allan

[Bryan in Woodstock]

It's very easy to pull out the bottom can to empty. Two lexan windows let you keep an eye on chip level. Each grey can has a 1/4" thick x 2" wide oak strip inside in the middle to keep the plastic can from collapsing. The only problem of using the grey rumbermaid cans,made from soft flexible plastic and my 3 hp 4 bag DC has the ability to suck them flat, LOL! The bottom can then easily empties to a large garbage bag. Plywood square screwed to cyclone is fastened in the corners for support when bottom can is being emptied. Weight of cyclone helps seal the plywood to the bottom can. An improvement would be to have a short length of 8" pipe between the cyclone bottom can and plywood lid.
Top ehaust pipe is 6 inch snap lock pipe with plywood support. Intake is a 6" hvac register end boot cut to fit curve of can, screwed and caulked in place. Cost - under $50.
P.S. if you are looking for more suction in an offshore DC, look at the 3 hp 4 bag units, they can create a lot of suction, compared to the 2 hp units, for a small shop.

[Allan Johanson - South Su]

Actually, all you really need is a way to stop the dust from going in your lungs. A $30 cartridge respirator will do that if you don't have a beard. It gets more expensive for a proper fitting system with "face fur" as Ken calls it. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Always wear the respirator when you're in the shop and clean up the mess at the end of the day (or sooner if it needs it) so there isn't a fire or slipping hazard with the dust everywhere.

As your wallet can afford it, buy your initial system or upgrade your current system so it will grab the majority of dust bits, but keep wearing the respirator.

I know I'll keep wearing mine.

Take care,

Allan

[Bob, in Lachute, Qc.]

Allan,

I was responding to your use of the term "Spews Crap", regarding the industrial cyclones. To me, you appeared to suggest that these industrial cyclones, weren't worth a "hill of beans". That only Bill's cyclone, was capable of "incredible separation efficiency".

As for testing yours, hey, I'm not knocking it. In fact, depending on how you finally duct it, even that 2.6" SP might be enough to make you happy. I remember you specifically said you were going to sometimes operate as a two person shop, with your wife using a second machine simultaneously.

I have no idea how you intend to adapt that 8" pipe to your machines, or, too what level of draw your looking for, when those are both operating. I'm assuming you're not going to run 8" pipe, to a router-table, for example, but hey, if your happy with that, why not.

I know from what you've previously posted, that you think even the OSHA, or NIOSH standards, are not enough for your homeshop, even though the standards, are there to protect woodworkers with career-long exposure levels. That's up to you.

In your case, I'd have considered a 15" impeller, or larger. Why not. You certainly have the motor to handle it. With 8" pipe, you'd be better off, for not much more money. Just the difference in price, since you could easily sell the 14". I think Oneida even sells a 15" or 16" impeller. So would Sheldon, Canada Blower,Kraemer, Belfab, or anyone else who makes larger dc's.

My only concern with your blower, was your decision to go with a much larger inlet diameter, at the blower's intake. Didn't you decide to go over 8" there???? I might be wrong, but I thought that's what you posted once. Seemed to me it might be even larger.

Typically, engineered blowers, use an inlet diameter, 1/2 the impeller diameter. For a 14" fan-wheel, that's 7". That's where the suction is being created. The difference in air velocity, from the entry velocity, to the velocity at the fan-wheels tips. If you "over-size" that inlet, you won't create that "differential". If you went 10", I'd suggest your draw would appear weak.

With 7" diameter pipe, you can easily flow 1200 cfm, at not too high a resistance. Velocity would be 4492 FPM. that'd take care of a table-saw, and a router-table or scroll-saw, albeit at NIOSH or OSHA levels. I don't think there's any escaping swapping out for a larger impeller, if you want higher volume. With 8" pipe, I'd go 16" if I were in that situation.

All the best, Bob

[Ed/Leaside]

Just to clear things up, Sheldons' impeller is 205 net plus GST and RST at 15 percent, and includes shipping/handling in the $265 price listed on their site.

[Bob, in Lachute, Qc.]

Lol Art,

I really get a kick out of Allan's passion too. I think the arguments are VERY positive, and most certainly "fuel" the energy to dig a lil' deeper, looking at cutting-edge technology, rather than just what's available in the magazines, etc.

As far as I'm concerned, the debate here at CWW forum, is as good as it gets. Just check out the debate on forums like "Woodnet", by comparison. Gotta be the worst I've seen. Debating the merits of $139. Harbour Freight dc's. Geesh.

Although I'd been passionately looking into dc's for a few years, I basically stopped looking, after i bought my Belfab. It is purely because of Allan's energy, that I got re-interested. I learned a heck of a lot, too. Especially where filtration was concerned. I had always concentrated on airflows, but never looked at the "nitty-gritties" of industrial filtration. That's been a real eye-opener over the last year or so.

Had it not been for Allan's passion, that never would have happened. Cheers!!(Bob hoists favourite beer-mug ;-)))

As for the preseparator, well Art, the sky's the limit. Basically, it just involves velocity. You want to get the waste to the pre-sep, but you also want it to stay there, and NOT get blown through to the dc.

Here's the "Basic" idea.

Air moves through different diameter ducts, at different velocities, even though you're still only moving one volume(cfm).

Let's say you're using 6" pipe at a machine, and your drawing 800 cfm. Well, the velocity through the 6" pipe, would be roughly 4079 fpm. That velocity is what suspends the waste in the airstream. When that air enters the larger diameter pre-separator, it slows dramatically. The pre-sep, acts like a large diameter duct.

If the presep is 24" diameter, velocity slows to 255 FPM. That's so slow, it can't support waste in the airstream. The waste "Falls" out of suspension, to the bottom of the drum. Naturally, there will be some turbulence. The very fine "floaty" stuff, will float in the air inside the air chamber.

As for the outlet, well, if the outlet is 6", then the escaping air, re-accelerates to 4079 FPM. That will "suspend" any waste that gets in contact with that airstream, taking it to the dc. If that's a problem, just enlarge the outlet, 'til your happy. Going with 8" there, your velocity would be 2293 FPM. Again, that's well below particle suspension levels, and reduces outlet resistance. Just use a "taper" fitting, to get back down to 6" pipe.

All the while, you moved a steady 800 cfm. it just changed velocities, as it entered the different diameters.

There are infinite possibilities with pre-seps. You don't need a drum. You can use a box. The entry could be on the side, or top, you name it. Totally up to you.

The only difference with a cyclone, is that the pre-sep, is contained in the same unit as the dc. The cyclone's shape, enhances separation. The higher that separation efficiency, the higher the price you pay in resistance, and airflow reduction. The cyclone's body IS a pre-separator.

Pre-seps, are not only limited to "pre-blower". The intention is primarily "pre-filter". You can have push-through cyclones for example. In a case like that, the waste goes through the material-handling fan. As the dust-laden airstream enters the cyclone's body,(larger duct), the waste falls out of the airstream, to the collection drum, or hopper, etc. The escaping air, finds it's way to the filter.

Again, just size the outlet, larger than the inlet, to reduce velocity below particle suspension levels. That in turn, reduces resistance. That resistance causes "pressure drops".

All the best, Bob

[Bob, in Lachute, Qc.]

Very interesting Bryan, and I agree with you regarding some of the 4 baggers. Garrett's 4 bagger Delta, was a strong performer, from what I gather. With good filters, they can do a heck of a job. Some are badly undersized impeller-wise, so that's an important consideration. Unfotunately, all too often, the good one's, just get lumped in with the bad. Not fair.

The 3hp 4 baggers, generally are intended for operating two machines simultaneously, and use 8" pipe, or 7" pipe. You may want to rethink your pre-sep's porting, if you want to benefit from that.

Using 6" is ok, but the increased resistance, will flow less air. Still plenty for single machine operation however.

All the best, Bob

[Bob, in Lachute, Qc.]

Mike,

That's exactly why I mentioned pre-seps. Sure, they're not as efficient as a cyclone, but if that means a cup of waste in the bags, compared to a few table-spoons, who cares. I sure as heck don't.

Mike, did you know you can re-arrange your components quite easily, if you wanted better draw???? For example, you could have your shop ducting go right to the blower. THEN, have your blower outlet, connected to the pre-separator.

From there, port the pre-separator, directly to the bag-tree. The blower can sit right on the floor, beside the pre-sep.

You can even get rid of the bag-tree, and make a simple box, on legs. Mount a filter to the top, and bottom of the box. Just like the Belfab.

http://www.belfab.net/jj.html

What THAT would do, is allow use of very large diameter outlet ducting on the preseparator. You could use 8" diamter pipe, for really low resistance. That duct could even be very inexpensive , and very thin-gauge pipe, since it can't collapse. The inside pressure, would be positive pressure, since you're blowing, not sucking.

All the best, Bob

[Bob, in Lachute, Qc.]

Garrett, That's, why I use a pre-separator. I wouldn't want to empty bags either.;-))

All the best, Bob

[Mike Harris, London]

You guys seem to be the resident experts on DC's.

For the Newbie's and week end warriors, you's guys design the cheapest but most efficent DC system you can think of.

This is something I think these guys would really benefit from.

What do ya say???

Thanks
Mike

[Allan Johanson - South Su]

Sounds good....but there are lots of variables.

I don't want this to be a long post, but here's a consideration:

- One extreme: Working in the shop alone, a certified cartridge filter respirator and a broom can do a lot. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

- Another extreme: If you are like me, I have a wife who has asthma. Grabbing all the dust I can at the source and CONTAINING it is a priority to me. Money is secondary. Welcome to the world of large DC units.

- Majority of folks: Is the often quoted "magic number" of 800cfm really that important? Jaws are dropping now....but let me explain. Look at the AAF tables and you'll see that most machines that require 800cfm at the tool have two hookups. So...for the newbie or weekend warrior who does NOT have an overhead table saw guard with DC hookup or two hookups on a bandsaw, and only has a few basic tools, you can probably get away with 440 cfm.

440cfm!!! Yes, some folks will probably want to shoot me for mentioning that. The one basic tool that according to the table needs 785cfm is a planer. But that's for a planer up to 20". A 12" planer could get away with less than that and I ran my 12" planer with a puny, carry under your arm 3/4HP DC unit. The smallest "DC" you can buy with a microscopic 9" impeller.

If a friend of mine wanted to get into woodworking and couldn't afford much to start out with, I'd tell him to buy a quality cartridge respirator and wear it all the time.

Then buy a basic 1.5HP DC unit on sale that already comes with a semi-decent bag. If there is a concern about the bag, for his birthday or Christmas, ask the family for an aftermarket bag like the ones LV sells or equivalent.

The respirator will protect his lungs and the 120V DC unit won't require an electrician to come in and set up a 240V circuit.

This DC unit could also support a SMALL duct network and probably still maintain 470cfm with 5" pipe in many cases.

You could even do some experimenting with a homemade preseparator to slow down the impact of wood dust on the filter bag. Grab a garbage can and make one. I made one for that puny system I used to have from an empty container of drywall mud.

There ya go. That's one option anyhow. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Allan

[Bob, in Lachute, Qc.]

Mike, here's what I'd do.

1. I'd mount a blower directly to the side of a box, on 4 legs. it would look much like a Belfab LW.

http://www.belfab.net/lw.html

I'd have a "common" plenum, shared by the two drums I'd use on the bottom, and two large capacity needle-felt bags on top.

Cost= blower,bags, and drums.

2. Designing it like the Belfab JJ's blower, you wouldn't even need a blower housing, just a pipe, and a flange.

In THAT scenario, I'd have pre-separation. I'd have a plenum(made of mdf), covering two drums. The inlet, would be at one end of the plenum, directly across from the plenum's outlet. That outlet, would be the blower's inlet. You COULD add an aerodynamic entry bell, like you see on the ventilation blowers, to decrease entry losses.

As soon as the air enters the plenum, it sheds velocity, due to the increase in area volume. Waste falls into the drums. The drum closest to the inlet, would fill first. Once that's full, the waste would blow across the top of that drum, and waste would drop into the second drum. You could use 1 drum, if that's what you wanted, to lower cost.

When you think about it, that's EXACTLY what you're doing by using a JJ, with a pre-separator.

All the best, Bob

[Dave in Acton]

Hi Art
Sorry I didn't get back to you last nite It's not easy having a business and hobby in the same shop.The presepartor is a 45 gallon drum as you can see. The top is 3/4'' mdf with two 6'' holes cut into the top. I placed the holes close to the sides of the drum.In one of the holes I placed a 6'' sleave and ran a piece of 6'' flex pipe to the D.C. Now this is the tricky part In the last hole I placed a 7'' elbow it didn't work I tried an 8'' elbow It worked But not great. Than I had a 6''to a 9''elbow made up for me and It worked great. I hope this helps
Dave

[Dave in Acton]

Hi Art
Sorry I didn't get back to you last nite It's not easy having a business and hobby in the same shop.The presepartor is a 45 gallon drum as you can see. The top is 3/4'' mdf with two 6'' holes cut into the top. I placed the holes close to the sides of the drum.In one of the holes I placed a 6'' sleave and ran a piece of 6'' flex pipe to the D.C. Now this is the tricky part In the last hole I placed a 7'' elbow it didn't work I tried an 8'' elbow It worked But not great. Than I had a 6''to a 9''elbow made up for me and It worked great. I hope this helps
Dave

[Allan Johanson - South Su]

- I suggested a "plug & play" method like what Bob did for his personal system when he bought the Belfab JJ

- Bob suggested a "make it yourself from pieces" method like what I did for my personal system when I built the cyclone

Is the grass always greener.... Things that make you go "Hmmmm....." http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Cheers,

Allan

[Bob, in Lachute, Qc.]

Yaaaaa,

andddd, we "Both" agreed it wasn't a cyclone;-))))) (ducking and running)

[Bob, in Lachute, Qc.]

Dave,

Just curious about that 6"-9" "elbow" you mention. Are you using that elbow INSIDE the pre-separator??? Sorta like a "deflector", to induce rotation????

All the best, Bob

[Fred in Windsor]

What are you guys going to do with all the spare time you'll have now.

[Art Mulder in London]

Thanks for the clear explanation. Much appreciated.

[Dave in Acton]

Bob
Yes Iam using that elbow inside the presepartor to induce rotation???
Dave

[Bob, in Lachute, Qc.]

OK, now I understand, since I couldn't see it in the pic. That rotation , is simply not neccessary. Entirely up to you. With the elbow you have however, I'm sure you're fine.

If ever you use a very restrictive branch, you can always eliminate that, to lower sp. Also, on the outlet, going to the dc, I use a large diameter reducer, there. 8"-7" at present, when using my small barrels.

You could also use an 8" elbow there, with reducers at the dc's intake. The 8" elbow, would cut the resistance to well below half for that component.

I will be using a 10" outlet, with the larger 55 gallon barrels. Velocity would be 2100 FPM roughly, wayyyyy below suspension level, and since the velocity through that elbow is so low, so in turn, is the resistance.

All the best, Bob

[Mike Harris, London]

The whole point of that was that I think there's alot of confusion out there at what people really need for a DC system. This subject has been thrown around soooo much that people really don't know what they need, can I get by on spending $500 on a system or do I really need to spend $1000 to $1800 like those guys are suggesting.

I know this to be true cause I have a couple of friends that follow the forum but don't post ask me. Or you get someone saying this subject has been thrown around like a dirty pair of jeans.

I'll bet there hasn't been more than 50 people build that cyclone, of coarse it's been very educational, I've learned alot and I've been WW for 14 years, I started with a shop vac worked my way up to what I posted earlier. Will I change it, not likely because it works.

Nothing personal guys, but can we give this subject a rest. How about posting some pics of your shops and projects, I'd sure enjoy seeing them, I always enjoy seeing fellow woodworker's work.

Respectfully
Mike

[Gerry]

With all due respect to Mike, I hope this thread continues because I am one of those who is trying to figure out what I (really) need. I have a basement workshop in a new home, wife complains about the dust all over her furniture. All I have now is a shop vac, with the following power tools: a planer, tablesaw, router in a table, mitre saw, etc.. I've learned plenty from the recent posts which have helped narrow down my choices and options. I have a day job and do WW in my spare time, so I don't have time to build a DC. I want, as Bob puts it, "plug & play" but I know that I could get hoodwinked into buying something more or less than what I really need. The other thing that I've learned is that the added costs, i.e ducting, are not insignificant. Also, that there are various materials to use for ducting, some better than others which I wasn't aware of. So, you see Mike, I for one appreciated all the information and I think that I can sort out the BS from good info. I agree that not all resposnses add to the wealth of knowledge but it is still good to hear the various personal opinions, it helps in applying the info to my needs, my budget, my ceiling height, and most importantly to appease my wife.

[Bob, in Lachute, Qc.]

Hi Jerry,

Hope you got my email. Sometimes those get returned for some reason.

Sorry Mike, but as you can see, DC's are of particular interest to some folks, and personally, I don't know why people who aren't interested, just simply not click on the link. I don't see why people interested in dc's, be limited from sharing views, or asking questions. I read less than 30% of the posts here. Just those I find of interest. Hand-tools, ole cast-iron, spray systems, dc's, humour, etc. It most certainly doesn't bother me, when I see someone post a subject of no interest to me. I simply move on.

Jerry, if you have any questions, feel free to email me anytime. I'll be glad to offer any suggestions, or clear up any questions you may have. While I'm most commonly associated with the Belfab, there are many other offerings out there, that seldom do get discussed. Some are ultra-low profile, and fit under a table-saw extension table. Good performance, built like tanks, but a bit of a pain to empty. Using a preseparator, would make them easy to empty. For someone with a very low ceiling, they're grrrreattt.

http://www.kraemertool.com/smport.htm

http://www.belfab.net/Lhp.html

For me, I don't really care what brand or type of dc I use, but I do like a quality, reliable unit, with no-excuses performance. The Belfab's bullet-proof. 100% satified with mine.

All the best, Bob

[Allan Johanson - South Su]

Thanks for posting that, Gerry.

Mike, I understand and respect your thoughts on this, but the only part I have a concern with is how is a newbie going to know what they really need?

The simple systems Bob and I proposed could work fine for a bunch of folks (even though the target cfm is probably only around 500cfm and that does NOT meet industry safety standards), but may not work well for someone who has a family member with asthma or some other respiratory/allergy ailment. That wasn't taken into account. You'll need to take extra steps if someone will be around with a respiratory problem and with some other folks posting how great their 1HP system keeps their shop super clean, a person with asthma might think that would be fine for them. But my wife has asthma and I know from experience with her what can cause problems. Especially when the dust particles that can really cause issues you can't even see with the naked eye. A shop might look clean, but could be harmful to someone with asthma.

So for anyone who has a respiratory illness, or for anyone who is generally concerned about their health, a basic system won't cut it.

******

How about this:

Going forward, when someone posts a question about what DC to buy, you can post something like:

- Always buy and wear a quality cartridge respirator that fits your face well. If you have a beard then you might need something more expensive. Talk to your local safety equipment supplier.

- If money is tight, wait for a sale and buy the biggest 120V system you can find that will run on a 15amp circuit. Typically sold as a 1.5HP unit. I've seen these on sale for as low as $269. Use as a mobile system with a length of 5" flex or for a duct system, run 5" duct to your tools with this and use 26ga HVAC snaplock pipe if you can't find a deal on spiral pipe in your area. Use metal foil tape (from any big box) or "high velocity sealant" from an HVAC supplier to seal ALL the joints.

- If you like to build your own custom box, ask Bob for specifics because he has a bunch of ideas for the energetic person to make a custom unit that will perform well.

- If you or any family member has respiratory health issues or for any other reason you really want to control the dust, then you will need something more powerful. There are other tips and tricks for someone who has a basement shop or one attached to the house in any way. Ed made this thing called an "air knife" that is pretty cool that helps stop dust-laden air from going through a doorway.

*** Then the person asking the question can expand on that info, because as we all know they won't say up front what their situation is. Kind of like "Hi, I'm new here and I want to buy a table saw. What kind should I buy?" http://www.canadianwoodworking.com/forum/images/smilies/smile.gif

Cheers,

Allan

[Mike Harris, London]

I guess this is a case where if there was separate forum for different topics, those who wanted indepth information could go there. I work shift work and when my work is done I tend to read almost all threads, it's my entertainment, and believe me, it's sometimes real entertainment. But it's gets feeling like reruns sometimes and I get a little touchy on night shift.

I certainly didn't intend offend either of you(which I don't think I did) as you both are great contributors here.

Moving on.
Mike

[Bob, in Lachute, Qc.]

Lol Mike,

I know how you feel, lol. And absolutely no offense taken at alllll. Heck, there's something about dc's that just generates soooo much debate. Geesh!!! Even I get confused trying to keep up with the threads. You say something, then someone jumps down your throat about something else, and you both agree, but they missed that you had already said that, in response to another question, Geeshhh!!!

I think it's important though , especially for newcomers. Many are "lurkers", and simply view the thread, afraid to ask questions. I always try to be concious of those people, and would ALWAYS welcome their questions. There's no such thing as a dumb question, welllllllllllll, maybe in Allan's case(ducking and running);-)).

Really though, the only dumb question, is the one you DON'T ask.

While many will have individual preferences from model to model, the principles of air movement, are a "constant", and a LOT simpler, than it sounds at times. For those Lurkers and newbies, getting a good basic understanding of air movement, will make your dc choice easier, and suitably appropriate to your needs.

Have a greatttt Weekend, Bob