Wrap-up of questions so far...

[phil (admin)]

Many people have asked questions in the forums where I make my initial announcements. That is fine, but I thought I would recap answers here to avoid overlap.

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Q: Length of video is too long.
A: I agree, I'll do something about that. I was worried that if I edited it people may feel light there was some slight of hand.

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Q: Could you add the baffle to an existing design like the Lee Valley that has the exit port in the center.
A: Results less than optimum because of the angles of these ports. Really need more typical cyclone alignment. Don't get me wrong, the baffle will help the LV, just won't be optimum.

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Q: If you suck up the pile as fast as you can [in the video], does the filter still stay clean?
A: EXCELLENT question. There are two things you don't want to do to a cyclone: (1) Stuff it (where you feed it too much debris and too little air) and, (2) Starve it (where you feed it little debris but little air, too).

If I do a full seven gallon stuffin of my cyclone (feeding the entire seven gallons in what I approximate as 1.5 minutes or less--I've never timed it), probably about a cup of debris will make it to the vac.

Of course, full cyclones are not immune to this either.

The answer is that the entrained particles have to be entrained (in air) to be separated. If there is no air, there is no separation.

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Q: Very impressive. How does the cyclone do with extreme fines, like you get using your random orbit sander, or a drum sander? I would be interested in making one as I'm tired of beating the squat out of my filter to knock the dust out of it. Please keep us appraised of the larger size tests, this might be the ticket for my drum sander with my HF dust collector.

A: It would certainly help but in reality I've read complaints even from people with full-blown cyclones that have not been satisfied w/ performance on their drum sanders. If I can get some interest I may try to find a volunteer in the Milwaukee area w/ a drum sander where I can do some testing.

I have done testing w/ orbital sanders and have been happy with the results as long as I make sure I don't starve the cyclone. The 1" hose I have for my Porter Cable sander is okay. But I always open another blast gate a little to make sure the cyclone has enough air to perform separation.

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Q: I assume there's something special about the angle of the inlet as well as its placement? What's that wing-nut looking thing in the middle of the baffle?

A: The placement of the inlet is somewhat of a compromise no matter what we do. That is because the ideal placement would be a tangent to side of the can, but given the size of the inlet and other obstacles, the best we can hope to achieve is to get the inlet close enough to the side that it somewhat gracefully eases the incoming air into a circular rotation in the can.

The wingnut is just there to cover the 1/4" hole in the center of the baffle that is a remnant of the circle cutting jig I used to make it.

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Q: I use the cyclone system but it is the small pail size. As an amateur who doesn't run the shop every day, at least not the sawdust making machinery, this seems to be all I need. So, how will this work with this size? It appears reasonably straightforward to build, but your lid will cut down on the available space inside. Should I go to a larger size can?

A: The baffle reduces the capacity of my 10-gallon steel garbage can by approx. 2.5 gallons. If you can live with approx. 7 gallons of capacity (quite a bit for the average part-time home woodworker), I'd say to just use the 10-gallon can. Otherwise it can be ramped up, but there is a limit (we need enough CFM to enduce full rotation and therefor adequate separation).

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Q: Phil, that is awesome. Do you think a similar one would work if you used smaller pipes and a five gallon bucket and ran it with a shopvac? And did you do anything to ensure that the cyclone lid was snug against the trash can? How did you avoid leaks?

A: This small model I demo actually is used w/ a shop vac. I used a ten gallon steel garbage can, which really isn't that much larger than a 5-gallon pail. You might be able to squeeze the design into a smaller 5-gallon pail, but the performance would probably suffer a little unless (like you mentioned) you reduced pipe diameter accordingly.

There is another reason to avoid plastic pails, though. And that is to avoid static problems. I'm not concerned with the chance of explosion, but rather have noticed that static charged plastic can interfere with the operation of the cyclone.

The tops I've made during have been of MDF and sometimes (when I've got scraps that are large enough) baltic birch. I cut a lip on the plywood and it "snaps" down into the steel can quite nicely. No leaks, and I don't use any weather stripping.