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Just picked up a Grizzly G8027, after previously using a small shop vac + dust deputy cyclone.

I am, possibly incorrectly, assuming that I should be using both together. So I am considering running the 4" hose from the dust collector into the cyclone, and then back out. That means I go 4" to 1.5" and again from 1.5" to 4" to attach to my table saw, jointer, etc...

UPDATE - It turns out I could also use a 2.5" fitting instead of 1.5" fitting (shown here, it's a tapered end on the dust deputy). Is that any better?

Or should I get a trash can separator lid off of amazon?

So my questions are:

  1. Am I reducing my CFM by doing this?
  2. Do I even need the Dust Deputy? From what I understand the cyclone is great to use in conjunction with a dust collector to minimize the dust that makes it into the Grizzly bag
  3. Bonus: You see the hose I have. I need something sturdy that I can use coming out of the cyclone into the woodworking equipment (4" ports), which will facility a lot of plugging in / out all of the time. Any ideas?

In these photos, please disregard the terrible 4" connection into the deputy, I'm trying to find the right adapters at the moment =).

Collector 1 Collector 2

  • I wonder if this question belongs on the physics.stackexchange site. My initial thought is that the 1 1/2" opening will increase the air velocity and change the effectiveness of the dust collection in the first stage. Don't know whether that will increase or decrease performance. I think it will also put strain on the motor due to reduced airflow. – Ashlar Sep 3 '16 at 17:22
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Yes, you just murdered your CFM. In short:

  1. Any cyclone adds resistance
  2. Sizing down from 4" to 2.5" or 1.5" reduces CFM because the cross-section of the pipe is dramatically reduced
  3. Flex hose adds more resistance than smooth pipe
  4. Numerous sharp bends (90 degrees or more) add significant resistance

See https://woodworking.stackexchange.com/a/3218/49 for more information.

As you noted, you are using a cyclone intended for use with a shop-vac; however, Oneida manufactures a different 4" model intended for dust collectors.

For what it's worth, if you run the numbers, even the best 2HP or less dust collectors hooked up to a tool with a mostly straight 10' run of 4" flex hose will barely produce the necessary 4000 FPM air velocity at the tool to capture most of the dust.

  • At this point, I have found this: eberhardt.bz/GME_Wood_Land/GME_Woodworking_Stuff/4_Information/… along with bill pence's: billpentz.com/woodworking/cyclone/dc_basics.cfm. From these, I see that this dust collector can't overcome a cyclone, let alone with a 2.5" diameter opening... the static pressure will quickly be more than this can handle. Looks like I'll return it for a one which has more static pressure! Thanks. – Shackrock Sep 4 '16 at 11:48
  • As a follow up, why do they sell dust collectors this small? As you note above, and certainly this grizzly, is incapable of producing proper CFM to even keep dust chips flying in the flex hose, what a marketing sham! – Shackrock Sep 4 '16 at 11:49

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