Cyclone or Standard DC with cannister

[sdj]

I know many people "grow" from a standard DC to a cylcone.
The way I cost it out, the "plumbing costs are basically the same" assuming you are going to use 6" duct runs in both cases.
Cyclone DC with a cannister start at $795 and a HF 2HP with a cannister filter will cost me around $300.
I have read Bill Pentz' website on the advantage of cyclones.
Why do people convert to cyclones?

[r.palmer]

Cyclones can handle more material with more suction at the tool, if they are good ones like the Pentz design. The ones like the Pentz design, or the Grizzly, are rather tall, some of us do not have the overhead height to use one in our shops, but its the best ideal solution for getting more fine dust, because it has the power at the tool to do it, of course, six inch pipe is required. The DC with a good filter can, may be good enough, unless you have severe allegies that are life threatening, or kids with asthma. Trying for the ideal is related to health issues, not to anything else. If your shop gets rather large, or you use it as a small factory, the power has to go up to meet the need. To clean out those long runs of pipe. Of course, B. Pentz has serious health issues, so good is not good enough, great is safe.

[LarryG]

Other advantages of a cyclone:

Larger chips are separated out before they get to the impeller and filter. The risk of damage to the impeller itself is probably fairly small, although big chips hitting it can certainly kick up a worrisome racket. The filter is another matter; the smaller the particles are that reach it, the less likely it is to be punctured and clogged.

Separating the big stuff off first makes emptying the system much easier, and at least in theory, safer. A jointer or planer will throw off enough big chips to fill up a lower bag in a fat hurry, which means you have to empty or replace it immediately if you want your system to keep working. And every time you do that, you're going to be stirring up the fines that represent the biggest danger to your lungs -- which is why a cyclone is theoretically safer, since the lower bag holding only the fines will have to be dealt with much less often. You'll still have to empty the cyclone's separator drum almost as often but since the big chips tend to be light and fluffy, they're not as heavy and hard to deal with as when everything is packed into the lower bag together. (Of course the flip side of this is that when the lower bag contains nothing but densely-packed fines, that sucker's gonna be heavy when it finally gets full.)

I don't have a cyclone, but wish I did. No way my current shop will accomodate one, but when I build my new shop, I'm going to have one.

[RichG]

I just got my HF DC delivered today (I guess I know what I'm doing this weekend!). I'm figuring this out as I go, but I'm planning on using a seperator for now with the standard bags. I've been following the other discussion on the Wynn conversion filters and may decide to do that too (not sure which one though).

A couple weeks ago when I got the seperator going I just used a shop vac hooked up to it and was very surprised at how well it actually worked and how little made it into the vac canister. I was doing alot of jointing so it wasn't very fine dust but I had to empty a 30 gal trash can 3 times and there was hardly an inch of dust in the shop vac! I'm hoping the DC will be alot quieter, filter as good as the shop vac and provide alot more suction. I was clearing chip dams with almost every other pass on the jointer.

-Rich

[LCHIEN]

One reason is that the cyclone is a two stage separator; the cyclone is scientifically designed to remove particles of a certain size and density. These swirl centrifugaly around the outside of the cyclone and slide down the wall to the bottom of the cyclone and fall out the bottom port into a can. The lighter particles don't get pushed so far to the outside and are sucked up the central votex and ot the top port. The pass thru the blower and are caught by the fine filter.

There's several advantages to this arrangement:
One, big stuff will fall thru the cycle to the first collector bin and not hit the impellor and possibly damage it. Two, only fine stuff will hit the filter canister and it won't get plugged by big items. It's easy to empty the bin.

Some will say you can get the same thing with a trash-can home made separator. I would think that a properly flowing DC system (in the 2 HP class) will scour out most trash can separators. The cyclone design calls for a certain slope and a certain height (something approaching 5-6 feet) and diameter to achieve a certain articulate size cut.

There might be something to better air flow with a cyclone system
but I'm not really sure.

[r.palmer]

On an alternative failure of a chip separator..When I tried to run two 4" hoses into and out a duct taped together U path plenum box, about three 1/2 ft high, with a piece of clear plastic taped over the front, the near six inch pipe flow, pulled it pretty clean. It took me all day playing with it, to figure out I did not have enough room to build a tall complex box that would get it done, I was thinking drawer in the bottom, but all but the very largest bits I fed into a nearby blast gate, got sucked into the bag, and some of those bits rattled around in the box, and lay on the baffles, and I got my coffee cup stuck to my hand from all the duct tape, and it just seemed like the DC with that neutral vane was going to have to do. Glad there is no picture of that evening, it wasn't exactly high tech, or well engineered, but it seemed blasting a bunch of dust in a box, and pulling it around a luan maze was more interesting in the head than in front of the face. It gave me ideas, but not being an engineer, the ideas felt about as rational as reading a will to a dog.