Is this normal with a cyclone?

[Perry Holbrook]

I'm improving the dust collection on my Delta pin router today. For several reasons, I decided to use a combination of a small cyclone and shop vac.

To test it first, I "borrowed" the cyclone from my sand blasting cabinet. It is one of those small cyclones designed to fit on a 5 gal plastic bucket, I think some company calls theirs Dust Deputy, but I got mine from a guy who makes them and sells on ebay. I also picked up a shop vac from Home Depot. They call it a 5HP unit, which doesn't mean anything, but it has a 10 amp motor.

The set up is working fine, but before I buy a dedicated cyclone for this I have a question, which is "Is it possible to have too much vacuum attached to a cyclone?"

What I am seeing is after I am thru making a cut and no chips are being collected, some chips remain suppended in the cyclone making a rattle sound and do not fall out until the vac is turned off. I'm just wondering if I have too much suction from the shop vac causing this or is this normal?

I've been running it for about 2 hours and there is almost no dust inside the shop vac, so the cyclone is working just fine.

Thanks for any input. Perry

[Roy Clarke]

Yes the rattle's normal. I can't run mine without getting some fine dust going through to the vac, though it is just a thin coat on the bag that covers the filter. Perhaps I'm too fussy.

[Jack Hogoboom]

From what I remember reading, it is possible to have too much vacuum. I was going to add a cyclone in line with my Jet DC1200, but recall that it pulled so much vacuum it would pull all the chips out of the cyclone.

Jack

[Jim Becker]

Yes, you "could" have too much air movement, but be absolutely sure there isn't an air leak between the mini-cyclone and the bin under it. That will also cause blow-by.

[Chris Friesen]

From what I remember reading, it is possible to have too much vacuum. I was going to add a cyclone in line with my Jet DC1200, but recall that it pulled so much vacuum it would pull all the chips out of the cyclone.

Did you have an actual cyclone (ie. cone-shaped) or just a cyclone lid on a cylindrical drum?

The cyclone lids don't work well for full-sized dust collectors--as you said they can suck the drum empty. From everything I've read you can't have too much suction on a real cyclone. The ClearVue, for instance, uses a 5HP motor to draw around 1800cfm.

[Perry Holbrook]

In my case, this is an actual cyclone, just a small one.

Looks like I have gotten a yes and no answer. If it is possible to have too much air flow, do you think I can match the vacuum to the cyclone by restricting the intake at the dust hood?

Perry

[J.R. Rutter]

Like Jim said, you have to have a well-sealed collection container under a "pull-through" cyclone. A cyclone designed for the higher velocity (taller, more gradual taper) wouldn't pull any more through than any other cyclone at lower velocity. Usually you want high velocity to get better seperation.

Yes, you can restrict the inlet to move less air, but I wouldn't worry about it if your filter isn't clogging. Get as much flow at the cutter as you can...

[Phil Thien]

I have read that users w/ ClearVue cyclones have observe the same phenomenon with perfectly sealed drop-boxes. It appears it is the result of some particles being the perfect weight/size to stay suspended. Doesn't cause a problem, and they drop once the blower stops.

[Jay Albrandt]

Perry,

I built the Pentz cyclone and occasionally it does the same thing. I asked Bill because I thought I had a leak in the drum causing this and he said it was normal. Some pieces are the right weight and dimension to get caught in the air stream and it is called "sailing".

If you have no dust in the vacume, everything is working fine.

Jay

[Perry Holbrook]

Thanks everyone. I'll go ahead and order another cyclone to make this permanent for the pin router.

Perry