Super Dust Deputy XL vs Thien baffle

[Staffan Hamala]

I'm planning on replacing my current dust collection system with a new, 6" ducting and a more powerful dust collector (at least 3 hp).

My current plan is to use just a blower (without filters) and vent outside. I'll buy a 3-5 hp DC and remove the filter bags. I should get more suction without the filters.
Before the blower vents outside, I need to separate the larger chips and sawdust with some kind of cyclone or dust bin separator.

Right now, I'm trying to decide if I should go for a Thien baffle cyclone or a Super Dust Deputy Plastic XL:
http://www.oneida-air.com/inventoryD...o=AXD002030AXL

The SDD XL has a 6" inlet and outlet. It's rated for 850 - 1,200 CFM and a 3-5 hp motor.

The Thien baffle is a simple DIY build that is appealing to me. However, I've read that you lose 35-40% of the suction (CFM drops) with a thien baffle compared to running the DC without it. I'm concerned about this, as I really would like to get 1000 CFM at my machines.

Has anyone done any comparing of the Thien baffle vs SDD XL vs a real cyclone (e.g. Clearvue)?

A real cyclone is a bit too expensive for me, and I would also have a hard time finding a place for it (the ceiling in my shop is too low for a full size cyclone).

If I already had a more powerful dust collector, I could experiment with a thien baffle. But it might get expensive to buy a lot of stuff that I won't be satisfied with (and end up replacing).

[James Gunning]

I think you would find out the SDD would outperform the Thein baffle. If you were to get the build just right in all respects, the performance of the Thein baffle might possibly approach the SDD, but not that likely to surpass it. A 3-5 HP blower (12-16" impeller) combined with a SDD XL and venting outside would be a really good combination. The best cyclone you can buy right now is the Clearvue. However, the SDD XL has most of the details that the Clearvue has and is probably not far off in performance. Please let us in on the build details.

[Andy Giddings]

I've tried both a home made baffle and a Super Dust Deputy. I placed the baffle in the collection bag area under the filter in a single stage unit. Reason for this was to stop the dust and debris from going into and clogging the filter, without stealing any suction as its installed after the impeller. It works very well in this config but does not separate as well as a Deputy (filter will eventually clog more frequently than with a cyclone). Look for a Fine Woodworking article on Soup Up Your Dust Collection as they performed a bunch of measurements showing the different configs and results.

I believe they measured the cross over point (in terms of air flow performance vs dust collected) at around 100lb. That is, you get better airflow with the baffle (post impeller) until you've collected 100lb of dust when it switches and the Deputy performs better, unless you clean the filter. The cfm drop from the Deputy was significant (Baffle 500CFM, Deputy 400CFM) so I would expect a baffle in front of the impeller to be at least the same drop.

My main reason for switching from the baffle was to reduce the number of times I have to clean the filter.

[Curt Harms]

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I believe they measured the cross over point (in terms of air flow performance vs dust collected) at around 100lb. That is, you get better airflow with the baffle (post impeller) until you've collected 100lb of dust when it switches and the Deputy performs better, unless you clean the filter. The cfm drop from the Deputy was significant (Baffle 500CFM, Deputy 400CFM) so I would expect a baffle in front of the impeller to be at least the same drop.

My main reason for switching from the baffle was to reduce the number of times I have to clean the filter.

That sounds about right from my experience. I doubt I produce more than 100 lbs. of dust & shaving per year and clean the filter annually. I know the baffle is a substantial improvement over not having some sort of separator. I recall from Bill Pentz' site that 'push thru' separators have a little less performance hit than 'pull thru' separators.

[lee cox]

I just went through this decision. My thinking was more between the SDD and the SDD XL. I opted for the SDD because I was on the low end of SDD XL. My thinking is you will get better fine dust separation being on the top end of the cyclone performance vs the bottom end so I bought a SDD.

I don't have mine working but I have the SDD mounted on a 55 gal drum. Christmas has slowed me down.

[Jim Dwight]

I used a thien baffle on my former 1 hp DC and it helped some. I have a dust deputy on my shop vacuum and it separates a lot better. It even gets most of the drywall dust when I use my little Festool hand sander. If you are venting outside, it is a question of how much of a mess you want to tolerate and apparently how much decrease in suction. The cyclone will definitely leave less dust to be discharged, it will be fine so you may not notice much at all. With the thien, I think you will definitely see discharge.

[Cyrus Brewster 7]

If you are venting outside the baffle will suit you just fine. You may enjoy building it. The necessity of a cyclone is really if you are using filters - you will need to clean them less often.

[Mike Henderson]

I have the SDD XL in front of my DC and it works great. No experience with the baffle.

Mike

[Doug Bowman]

My choice would be the Thein baffle - you are venting outside and all I would worry about is visible dust which a properly built baffle is very effective at removing.

[Brice Rogers]

I'm running a Thien baffle with a 2 HP Harbor Fright Dust collector and I'm venting it outside. Where I vent it, I have yet to see any debris.

There are a few different variations in the Thien baffle. I would recommend having the intake enter tangentially (like it is when you re-purpose the original metal center section of the single stage DC). I would advise against putting in a PVC 90 as it is too abrupt and interferes a little with the circular rotation of the debris. I would also recommend having the outer edge of the slot to be at the same point as the metal ring. I've seen some Thien baffles where the slot is inboard a bit and that might create a ledge that hampers dust flow. Use rubber seals - - it there are air leaks, it can interfere with the proper operation.

If you decide to build a Thien baffle, you could get better CFM if you use (for instance) 5" tubing between the suction unit and the baffle and between the output to your outdoor vent. If the inlet and outlet are 6", then I'd go 6". But I can't see anything positive by dropping down to something smaller like 4".

[Jerry Cummins]

I'm running a Thien baffle with a 2 HP Harbor Fright Dust collector and I'm venting it outside. Where I vent it, I have yet to see any debris.

There are a few different variations in the Thien baffle. I would recommend having the intake enter tangentially (like it is when you re-purpose the original metal center section of the single stage DC). I would advise against putting in a PVC 90 as it is too abrupt and interferes a little with the circular rotation of the debris. I would also recommend having the outer edge of the slot to be at the same point as the metal ring. I've seen some Thien baffles where the slot is inboard a bit and that might create a ledge that hampers dust flow. Use rubber seals - - it there are air leaks, it can interfere with the proper operation.

If you decide to build a Thien baffle, you could get better CFM if you use (for instance) 5" tubing between the suction unit and the baffle and between the output to your outdoor vent. If the inlet and outlet are 6", then I'd go 6". But I can't see anything positive by dropping down to something smaller like 4".

I did the same thing with a similar dust collector, and I have not seen a single speck of dust outside. It really quieted things down too.

[Ryan Mooney]

I have a thien that I made (top hat design, metal lined, flipped impeller to get a straight shot, pretty standard). A few of things I learned while tuning/using mine:

Narrower slot == better separation efficiency (up to a lot better, like basically zero bypass with gallons of sanding dust shoveled at speed into the intake). However it also meant that it clogged horribly with my planer shavings so I had to widen the slot out let those pass which now allows more fines into my filters. Its not horrible but the separation performance definitely took a hit. Something like ~all~ shavings (that fit through the slot) 99.9% of table sawdust and 95-98% of drum sander dust (depending on the grit/speed/...). Until I got the drum sander filter cleaning was the far end of never, now is somewhat common. On a similar note having the edges of the baffle VERY smooth seems to help as well, as does a sharp edge on it. This took me a while to get right (or at least right enough that it stopped clogging the slot up with planer shavings..) so ease of disassembly is nice.

I got back more suction power by taking all of the flex and bends out of the assembly than I lost due to the baffle. "Got back" is somewhat anecdotally based on how far from an opening it can suck up dust as I lack better measurement equipment. Bends and flex just kill throughput. I can't give solid numbers but the combined modifications were a small net gain in CFM over the stock single stage design.

I have sucked a few larger than desired pieces of wood, paper, etc.. up into the impeller (and stalled out the impeller at least once.. oops.. that really made a horrible noise). A cyclone wouldn't have had that problem.

[paul cottingham]

I have a thien top hat with a blower on top of it exhausting outside. Works great, with very little junk blowing out into the yard. I would try it before dropping the money.

[Staffan Hamala]

Thanks everyone! I'll go with the Thien baffle! :-)

[Mike Turner]

I have the 2hp HF Dc with the Thein tophat. I only use it right now when using the lathe..I use a flexible hose and was wondering if ridgid pipe would help me any.? My run of the flex piping is only 18 or so feet.