FWW Article on dust collector modifications

[Phil Thien]

I had a Jet 1100 and a 1883(3hp double bagger). I put clear bags on the outside of the lower hoop and canisters on top. I never got the results that everybody else did. I always had a pile of dust and chips on top of the baffle. Sounds like I got similar results to FWW so both of us must have done something wrong. My filters were caked no matter I cleaned them. It doesn't matter now because I have a cyclone now, but I always wondered what I was doing wrong.

It is always hard to say. Some people seem to be able to execute the concept, others struggle. The FWW article is really the perfect case of this, as I told them (in black and white) that the Jet wasn't the ideal test unit. Over a year later, their article appears, and they're using the Jet.

The reality, though, is that the baffle outperformed the cyclone until they ran over 100 #'s of material through the thing. And I suspect (just my guess) that they weren't patient in feeding debris into the unit, either. Had they instead used the unit is realworld conditions, and used the bag outside the ring, I think they would have found an even better result.

Some people are headed towards getting a cyclone no matter what. I equate them to audiophiles that are always upgrading their speaker cables and interconnects. I know a couple of guys like that, they barely even listen to music, and enjoy it. It seems their hobby isn't really the enjoyment of music, but rather the upgrading of their gear.

I know some photographers like that, too. They spend a ton upgrading their glass and buying high-end Xeon workstations for editing photos. One of these guys I know was having a problem and I was working on his computer and realized he had nothing more than tens of thousands of pictures of ... his cat. He had represented himself as a professional photographer, doing weddings, etc. Not a single wedding photo or any other photo of anything but his cat, and some pictures of the inside/outside of his home.

And there is nothing wrong with that. I'm just saying there are a lot of woodworkers that spend more time posting on these forums than they do making sawdust, yet they have a dust collection system which would be ideal for a small commercial shop, LOL.

I've been in some of those and have had owners boast "my filters never get any dust in them." Well duh, I look around and see barely any materials. I ask to see some of their projects and I see a few small decorative boxes.

If you use a cyclone a lot (like Steve Knight uses his CV) you will also find it loads the filters pretty fast. In fact, Steve gave up on cart. filters and build a plenum with bags because he got tired of cleaning his filters.

There are others with Oneida cyclones that have had the same experience, especially when running drum and belt sanders (which generate lots of fines). They sometimes blame the brand of cyclone they have, not realizing that the other brand may only be marginally better.

It really is just a matter of physics. To build a cyclone that get get the finer dust, you need a big (TALL) cycylone. Larger than most people would want to have in their shops. And those are expensive, I know of nobody selling them to hobby woodshops.

[Mark Ashmeade]

And there is nothing wrong with that. I'm just saying there are a lot of woodworkers that spend more time posting on these forums than they do making sawdust, yet they have a dust collection system which would be ideal for a small commercial shop, LOL.

You're bang on the money there Phil. I moved to a bigger shop, and realised that the 4" ductwork I had before just wasn't cutting it. That much was evident when I disassembled it for the move and got covered in sawdust that had been in the 4" PVC. I had one of your design baffles in a trashcan, and it was outstanding at separating the dust and chips. Barely any dust at all got to the bag (a HF unit). The HF unit wasn't going to handle the larger ducting, so I pretty much had to change it all out for a bigger design all round. So now I have pretty good DC, but spend too much time in front of the computer and not enough in the shop!!

[David Kumm]

I wish FWW had also put an oversize quality bag on the collector and compared cfm with the cartridges. I'm one of those guys Phil refers to as having way more DC than is really needed but I'm pretty much in agreement with his take. Cartridges are great on a large cyclone as they take up less room and the cyclone keeps the stuff out of them that degrade the material but the fines still come in. Cyclones for wood shops are pretty inefficient when the particle size drops. My widebelt has a dedicated bagger on it. I would not put a cartridge on a direct unit wih no baffle or separator and not put cartridges on a sander if I had a choice. Dave

[Wade Lippman]

If you use a cyclone a lot (like Steve Knight uses his CV) you will also find it loads the filters pretty fast. In fact, Steve gave up on cart. filters and build a plenum with bags because he got tired of cleaning his filters.

There are others with Oneida cyclones that have had the same experience, especially when running drum and belt sanders (which generate lots of fines). They sometimes blame the brand of cyclone they have, not realizing that the other brand may only be marginally better.

It really is just a matter of physics. To build a cyclone that get get the finer dust, you need a big (TALL) cycylone. Larger than most people would want to have in their shops. And those are expensive, I know of nobody selling them to hobby woodshops.

I would have about 2 cups of fines from the filter when the 55 gallon drum on my JDS 3hp was full; and a decent chunk of the 55 gallons came from a drum sander. The JDS is very short, so the separation probably isn't as good as other; so when people claim they get 2 tablespoons of fines, they might be right though I can't confirm it

OTOH when I had a 2hp DC, I put a separator like the one they tested on it. It got like 90% of the material, but passed all the fines. I found the filter clogged just as fast as ever and it cost a lot of suction; so I got rid of it. Their test confirmed the loss of suction, but claimed it eliminated the filter clogging problem.
I am curious if other people had experience like mine, or like the magazine's results.

[Peter Hawser]

Well, I'm sure Jet thought about their design completely on their own!

[Peter Kelly]

It is always hard to say. Some people seem to be able to execute the concept, others struggle. The FWW article is really the perfect case of this, as I told them (in black and white) that the Jet wasn't the ideal test unit. Over a year later, their article appears, and they're using the Jet.

I'm sure that decision had absolutely nothing to do with WMH being a major sponsor of FWW....

[Alan Schaffter]

It really is just a matter of physics. To build a cyclone that get get the finer dust, you need a big (TALL) cycylone. Larger than most people would want to have in their shops. And those are expensive, I know of nobody selling them to hobby woodshops.

As you may know, I have a tall (3D vs 1.64D) cyclone with 3 hp/14" impeller blower- I run it for quite awhile before I need to clean filters, but never put a magnehelic on it to monitor flow and SP so I really can't say if it is any better, and if so by how much.

What I will say, is that configuring it as a push through eliminates the potentially dusty mess of emptying a drum as others have mentioned- I detach a bag, tie it off and carry it to the curb. Where I'm going with this is, where do most folks put the baffle when they are using it with a DC (instead of a shopvac)- before or after the blower? Are any using a trash bag? Most DCs do not generate enough SP to blow up the bag, especially if the filter is not totally clogged.

[Michael W. Clark]

Alan,
You are correct regarding the dust bag at the bottom. However, one major advantage of putting the fan after the cyclone is that the cyclone will protect the fan from large objects that could damage the impellor. It also reduces the dust loading on the fan to minimize wear on the wheel.

There are a couple of indicators that are a good measure of performance when it comes to a cyclone and most centrifugal separators. First, is the pressure drop. It is an indicator of how much energy is being put into the device to separate the material. More specifically, the more pressure drop, the more centrifugal force applied to force the dust particles to the wall of the cyclone. The second indicator is the size of the cyclone. The larger the cyclone, the more time the particle is in the cyclone and the greater the chance it has of moving to the wall for collection. Of these two, the size of the cyclone tends to be more important for fines capture. There are limitations on the pressure drop, both practically and physically.

If Alan's cyclone were scaled down by half and still operated at the same volume, the efficiency would drop dramatically even though the diameter was reduced, which increases the centrifugal force. The efficiency loss is going to be most seen on the fine particles due to the efficiency curve of the cyclone. The amount of material that passes the cyclone is unknown unless we know the particle size distribution of the dust entering the cyclone. If most of the dust is 50 micron, the cyclone will probably still be very efficient at this size. If most of it is 5 micron, there will be a lot more dust that passes as a % of weight.

Cyclones that "fit" in most home/hobby shops are not going to be very good at the smaller particles, <10 micron. Depending on the proportional dimensions and the specifics of the cyclone design, you may get good separation down to 5 micron. Cyclone separation at 1 micron is not going to happen with most ceiling heights and budgets.

[Jim German]

I'm sure that decision had absolutely nothing to do with WMH being a major sponsor of FWW....

There aren't many dust collector makers that aren't sponsors.

Using a DC that isn't optimal for the baffles seems like a good thing to me, as it shows that there can be issues its use. I'm surprised that Phil thought so poorly of the article, as it seemed very favorable towards the baffle to me.

[Phil Thien]

There aren't many dust collector makers that aren't sponsors.

Using a DC that isn't optimal for the baffles seems like a good thing to me, as it shows that there can be issues its use. I'm surprised that Phil thought so poorly of the article, as it seemed very favorable towards the baffle to me.

LOL, there can be issues with the use of anything. You can have issues driving a Porsche 911 Turbo around with low-octane fuel in the tank. But when Car and Driver does their reviews, they use the recommended fuel.

Pointing out a problem doesn't mean I'm upset or think poorly of the article. Nothing could be further from the truth, I loved the article.

[Jonathan Clement]

My wife and I found that FWW article very interesting and it helped us determine that we could make at least one more improvement to our system. We already had a fiber barrel separator, but figured that replacing the 1 micron bag that came with the Delta machine with a Wynn NANO filter would improve the dust situation in our basement shop. The filter fit perfectly using the edge trim gasket that Wynn sells to accompany the filter.

wynn 1.jpg

[James White]

Jonathan,

How much of a hit would you say you took with the addition of the separator?

James

[Jonathan Clement]

James,

When you say "hit", what do you mean?

Jonathan

[James White]

James,

When you say "hit", what do you mean?

Jonathan

A loss in suction.As compared to no separator.

James

[Jonathan Clement]

James,

We don't have any way of measuring, but no noticeable loss as far as I can tell.

Jonathan