Help Me - Dust Collection

When I built my Shapeoko XL enclosure, I included a basic dust collection system. It’s a traditional two stage system, with a Dewalt shopvac providing the suction and a Rockler dust seperator separating/capturing the dust.

When I looked inside the dust separator I found (after weighing) 162.7 oz of dust. This was from plywood, hardwood and a small amount of polycarbonate.

I then took the bag out of the shop van, and emptied the bag into another container. I found that the bag contained 80.7 of very fine dust. Way more than I was hoping for, not sure if my expectations are justified but I as expecting about 1/10th of that.

The math suggests my dust collection system is only capturing 66.8% (162.7 of the 243.4 total) of the dust.

The lid of the Rockler dust separator has two 90 bends under the lid.

My enclosure was designed for these parts, I don’t have a lot of additional room.

So how can my dust separator be improved?


I’ve had about the same set up as but with a rigid vac. I also have a 1-1/2 up jet cyclone for about 7 years.
With my Rigid vac that I actually use exclusively in my shop does a much better job than the jet.
In my vac I have a disposable bag from Home Depot that collects the fines after the Oneida cyclone from Rockler. The innermost paper filter has not been changed in 10 years as it remains relatively clean so I assume I trapping most particles with these combinations of vacuuming.

The Rockler dust seperator looks far to simplistic on the underside…what prevents dust from basically jumping across the inlets…especially if your shop vac filter is getting dirty and not pulling as hard.

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Like Matt says the cyclone separators with the conical geometry have a very specific mode of air flow which separates the higher density particles and drops them out of the air stream. The pair of 90 degree elbows is not likely to be anywhere near as effective, and as your measurements indicate, the high performance of the cyclonic separators on small particles is what you seem to be missing out on.

Have you considered the Dustopper?

Some folks have been successful with it.

Following @WillAdams idea, $50 later I now have a three stage system. Which is silly, but it fit so why not try it. This setup will also let me reconfirm the initial diagnosis (that the rocker product is flawed) and see if the (half price) home depot solution is better.

I removed the bag from the shop vac, hopefully whatever resistance the extra dust collector added I got back by removing the bag.


The Rockler is basically a garbage can lid type separator. The garbage can lid separators are not as efficient as a true cyclonic like Onieda or others. The dust comes in the top of the can the dust is supposed to slow down and gravity drops the dust down. However with the garbage can type separators a lot of the dust comes straight in and the suction side just pulls it up into the vacuum. You could try to add a baffle between the in and out hose connectors. Additionally dump your bucket often. The more saw dust that gets into the can it is closer to the suction side and dust gets sucked on into the vacuum. I have an Onieda Super Dust Deputy with 4 inch in and outlets. The system came with a fiber drum and does a great job keeping the dust out of my dust collector. If I let the dust get too high in the can it starts pulling the dust into the dust collector bag and filter. If you look at the picture above with the red separator you can see that the dust coming in follows partly around the diameter of the separator, slowing down the dust and dropping it down into the bucket. The Rockler one the dust in just dumped into the can causing turbulence and a lot of dust gets sucked on over to the dc.

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$25 cyclone separator (dust deputy clone) over $20 metal bucket here, and I’m still on the first bag in my (Festool) shopvac/
The only catch is that a cyclone+bucket stackup will probably not fit in that space under your machine.

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I have the Oneida Cyclone (OC) and the Dust Stopper (DS). I bought the Dust Stopper so I could tuck everything under my work bench; I run the Dust Stopper with a HEPA bag and general purpose filter in the shop vac.

I think the OC is more efficient, but the DS does a sufficient job. I don’t have any quantitative data, but it just appears that the particulate in the OC bucket is more fine than the DS.

You could also try and make the Rockler more like the DS by building a Thein baffle for it.


first post…: ) Shapeoko XXL user for 2+ years

Before buying my second Oneida Dust Deputy I considered the Dustopper for space reasons but then I saw this useful DIY test/review:

The conclusions seem similar to what others are saying here.

Also, I fit my first Oneida Dust Deputy under a standard workbench by creating a recessed lid for the 5 gallon bucket from wood. This cut down on the bucket capacity a little but the extra couple of inches gave me enough space under the bench to connect the hose to the top of the Dust Deputy. I’m not making that change to my new one as I’m opting for a separate enclosure eventually. I used to use a Ridgid vac with “HEPA” filters/bag and the exhaust vented outside but I am now switching to the Festool CT15 with true HEPA filtration (as I understand, better seals around the filter to prevent air from bypassing the filter) and I will still try to vent it outside.


If you have a Festool you may want to consider the Ultimate version which latches onto the top of the unit — it’s pricey, but the convenience of the all-in-one setup is really nice.

Thank you for that research, the “Thein Baffle” appears to be part of the home depot Dustopper. And it looks like that is something I could add to the Rocker dust separator.

If I knew all of this before I built the enclosure I would have found a way to make the a true vortex solution like the Dust Deputy work.

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For those using 5 gallon buckets for the container I would suggest using the Gamma Seal Lids as they make life much easier.

They replace the snap on lids with a threaded lid.


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Thanks Will, that is a nice option. One thing about the Festool CT15 is that it doesn’t have a Systainer compatible top (?) so it wouldn’t be quite as seamless a match as with the other Festool vacuums. The other thing that is a little different with the Festool CT15 is that the inlet is on top under the lid, but I don’t think this limits using the Oneida Systainer version if a suitable Systainer compatible platform/base is built.

Oh, darn. I didn’t realise that.

Festool has an option — is it suitable?

Hi Will- Because the CT15 doesn’t have the Systainer latches on top of it the Festool Cyclone option unfortunately won’t fit as designed. But I do like the CT15 a lot even though it is a Festool anomaly and my Festool Systainers still look at it very suspiciously for not carrying them around.


I use an old small craftsman vacuum. I purchased a true small cyclone and made a. Top for a home depo 5 gal bucket, mounted the small cyclone. It captures 90% fines and dust, the vacuum filter is fitted with paper filter and covered with a foam wrap. I get plenty of suction using 1 1/4” pool vacuum hose . I also use the “sweepy ”. When in in use I see no visible dust passing though the sweepy, as the suction is strong. Bought the no name cyclone off eBay for less than $20. Tom

I can’t speak for the other options, but I use the Oneida Dust deputy with the 5gal bucket with a festool CT midi, and am still on my original bag in the Festool after 3 years.

I do replace the HEPA filter yearly


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