Cyclone dust collector question

Remember, Donaldson-Torit makes filtration systems for all sorts of uses, not just woodworking. You're right that almost nothing should make it through, but almost nothing is not nothing and in situations in which you're dealing with something where outside emissions are regulated that "almost nothing" can get you in trouble.

I looked at "Blue Tornado" and they mention a similar story on their equipment. The dust bags are the final filter. I think what happens, is that you use the cyclone as the "chip collector" and the bag collector as the dust collector.

mnterpfan wrote:

Hi Eric. I think you have the right idea. The cyclone exhaust goes to the DC intake, making the cyclone a "pre-cleaner." This protects your DC from taking large chips, screws, or other items that may damage the blades. The nice thing about a cyclone is that there are no moving parts.

Eric:

Yes, typical cyclone receives the junk from the shop, and has an extractor on the output. Most cyclones don't really need a filter (bag) on the outside of the cyclone, because they are extremely efficient about separating dust and debris from the airstream. However, if you are one to do a lot of fine sanding, I would think about using something with an "after filter" just in case, particularly if you live in the city and have a neighbor within a hundred feet or so... A typical DC will have a reasonable filter to use as an after filter, and most don't drop the airflow so much as to make you want to remove them....

Any decent Cyclone will drop most of the debris from the airstream. Even my home made cyclone (from a 55 gallon drum) will drop just about everything except for the very finest dust (which could really just go outside, as I live in the country and don't have any neighbors within a mile on that side of the workshop) when the cyclone drum is working. However, if you forget to empty the drum (cabinet in your case) you will get a lot of dust [DAMHIKT], followed by possible chunks into your DC bags. Thus, it is still a good idea to run the standard bag filter on your DC, and to check the drum (cabinet) often to determine when it is time to empty it.... Just to see what effect it would have, I left the bags off my DC for about a month (but watched the drum to make sure it was never over half full) and I had but the very lightest dusting of extremely fine dust in the shed (about 6x10 feet) the DC lives in. However, I don't always remember to check the cyclone drum, so I always run with the filter bags on my DC, just in case. This has saved me a bunch of work with the shop vac on at least one occasion in the past year...

With the homemade cyclone I have, I can run with the filter bag off of the DC without any visible dust output until the drum is at least 2/3 full. I would imagine a commercial cyclone could stand a higher level of debris before it loses it's effectiveness, however, in the interest of making sure our environment is protected, I would suggest you continue to use the standard bags your DC has, AND check the DC bags periodically. Any significant dust in the DC bags indicates it's way past time to empty the cyclone drum/cabinet!!!

Good Luck, I'm sure you'll love having a cyclone

Thanks

--Rick

mnterpfan wrote:

Rick.. I need a cyclone type lid for the DC being shipped to me... any hints/pic/plans available on what you built?

thanks, mac

I have no idea about how well these work, but am giving strong consideration to buying and installing one on my "cyclone-to-be". It's a monitor for the debris container that is supposed to trigger a audio/visual alarm when the level reaches some pre-determined point.

Tom Veatch Wichita, KS USA

HEY GUYS,

SINCE IT SOUNDS LIKE YOU ALL KNOW YOUR PRODUCTS QUITE WELL I THOUGHT I WOULD SHOOT OUT A QUESTION. I NEED TO PURCHASE A DUST COLLECTION SYSTEM FOR INSIDE OF A 1600 SQ. FT. SHOP. IT IS A SINGLE BAY AND IS CURRENTLY SET UP WITH , A TABLE SAW, PLANER/ JOINTER, CHOP SAW ETC. AND HAS NO DUST COLLECTION. THE LEASE STATES THAT THE COLLECTION SYSTEM CANNOT BE OUTDSIDE OF THE BUILDING, SO I NEED SOMETHING THAT IS OK FOR INSIDE AND HOPEFULLY NOT TOO LOUD. IF ANYONE COULD RECOMMEND A SUITABLE COLLECTION SYSTEM I WOULD APPRECIATE THE FEEDBACK ASAP.

BENDER

Bill Pentz has spent a great deal of time and effort putting together a wealth of information about dust collections systems. I'd strongly urge you to spend some time with:

Tom Veatch Wichita, KS USA

shoot out a question, or SHOUT it out? OUCH!!

you don't want the Harbor Freight 2 hp one.. I'm happy with it so far, but the one thing you wouldn't call it is quiet..

Bender shouted:

Bender,

(All caps on usenet is the equivalent of shouting.)

I have a low-cost dust collection setup that would probably work for you (mine is in a 2500 ft² shop) and you can look it over for ideas at:

Morris Dovey wrote in news:YEHnd.1$pn3.2625 @news.uswest.net:

Hi Morris:

I'm an admirer of yours (lurking fashion) and I'm interested in the HF dust collector, such as the one you describe on your webpage above, but am disappointed at the 30 micron bags it seems to come with.

Do you (or anyone else) have any advice for "better" bags that would fit on this HF machine?

Thanks in advance!

collector and mounting the motor and impeller on top? I mean something like the plastic garbage can lid thing, only an actual cyclone.

On 16 Nov 2004 04:49:40 -0800, snipped-for-privacy@yahoo.com (mnterpfan) vaguely proposed a theory ......and in reply I say!:

remove ns from my header address to reply via email

Rant on. HTH.

One thing to remember. A good cyclone will stop a heck of a lot. In fact I saw where the 'standard" bags on a DC are a waste of time if you have a good cyclone!

.......but.....and a big but...there are really fine bits (5 micron and below) that get through.........and the standard bags are "not needed" because they do not stop exactly these fine bits! It's being found that these fine bits are what really damages your lungs. So if you have a good cyclone (or not!), then you need proper filters on the outlet, not the bags that come with the DCs. Probably the ideal is cyclone, bags, then fine filter. Cyclone stops the bits, bag stops a bit more, last filter stops the real nasties. Each one is easier to "clean" than the next one. Final filter may not be cleanable at all.

There are filters called HEPA. High Efficiency Particulate Arrestance. Some filters are _called_ HEPA. Others _are_ HEPA, AFAICS. These are medical grade. "Boy in a bubble" stuff.

However, I have been advised that you do not really need HEPA filters for shop use. They are often expensive, small in area (less time before they need replacing as they clog), and often not reusable. There are industrial filters, that go down to .5 micron particle size, that are "concertinaed" to give huge area, and are a lot cheaper than HEPA per "cub ft of stopped dust", so to speak. Check with an industrial filter supply. That's where I went, and the guy was quite helpful. He could have sold me HEPA at twice the price, but was advising what he thought were better solutions for the real world.

Also remember that any filter system will need maintenance, and to be kept free-flowing. A lot of people say that bag filters increase in effectivness as they clog up, because the dust stuck in the weave acts as a better filter. But of course this results in reduced flow, so you lose a lot of the effect.

Rant off

Mark...

Did you visit the link above? What you're asking about is what [I think] I did. My plastic lids are clear and I hope to tell you that it sure /looks/ like cyclones in in the barrels.

My longest single continuous routing run was a bit over three hours - when I used a 1/2" bit to true (flatten) my ShopBot's MDF work surface. I removed about 1/32" of MDF from the entire 49" x

This in spite of a /hole/ in the upper DC bag - and the inside of the DC bags were still clean. HF did finally send me a replacement for the bag damaged when my DC was shipped; but I haven't much worried about installing it.

As far as I've been able to tell, the only part of the DC I really need is the motor/impeller assembly; and I've given some thought to building a box on wheels to hold the barrels (inside the box) and support the motor and impeller (on top).

Han...

I'm afraid I can't help much. I'm even considering /removing/ the bags completely from my DC to see if it'll move more air without them - and still not draw dust right through my separators.

There's been previous discussion on the wreck about filter bags for this machine and, to tell the truth, I haven't paid much attention. You might try a Google groups search on "HF filter bag group:rec.woodworking" (without the quotation marks.)

Morris Dovey wrote in news:dQVnd.183$ snipped-for-privacy@news.uswest.net:

I bought a heavier 'shaker felt' bag for my Delta (think HF, but Delta grey) 1.5 hp unit. My local Rockler had ordered some 72" tall ones, and had them sitting there for two years (you need 10' ceilings), and had marked them down to maybe $27. The top hangs from a hook in the shop rafters. (I think there's still 3 or 4 left, BTW)

I've half a can of chips & shavings in the trash can collector, and nothing in the plastic lower bag. There's dust on the outside of the upper bag, from running the router, biscuit jointer and some other tools, that aren't hooked up. The old, single stage system pumped dust through its upper bag, pretty badly.

Morris' idea about replacing the cart with a shop built version has merit. I'll wait for pictures, however.

Patriarch

Yes, I guess my question was can I use the funnel-shaped cyclone in the manner that you did, with the garbage cans. Incidentally, after seeing your site, I ordered one of the clear ones to try....will it work ok on a galvanized trashcan?

Just a note that will get flamed, but.... I have a whole 3 days experience with the HF unit with the 30 micron bags.. I say bags because as far as I can see, both bags are identical.. lol I hooked it up to the RAS and moved the DC into the path of a convenient sunbeam... cut a 3' scrap piece of 1/4 hardboard (what I seem to get the finest dust from on the saw) into 2 or 3" slices and had my neighbor watch the DC bag... he saw no floating particles. I know this isn't scientific, but the results were a LOT better than I expected..

no need to tear apart anything... the cyclone goes in between the DC and whatever it's sucking dust from...

it's just a garbage can with 2 hose connections, at least on of which should have a 90 degree elbow inside the can to make it swirl..