# My Thien Baffle Experience



## CharlesA (Jun 24, 2013)

I have a HF dust collector. Last year I got a 55 gal plastic barre off of CL and installed a simple box separator and vented it outside. I was very pleased with the suction, but it seemed like a lot of the dust was being vented outside. This weekend I put a pile of dust in front of the floor sweep and went outside before turning it on, and I'm guessing that 50% was being vented outside. Not good enough.

So, today I put together a Thien baffle quickly. I used the same 4" pvc as I use in my ducting for the baffle.

It may be that I could improve the construction of it a bit, but I think it ended up pretty close to right. My ovservations:
1) dust vented outside has dropped from 50% to imperceptible.
2) based on how well it sucked in from the floor sweep, I would say that suction has dropped 20-30%.

i'm going to keep it this way for a bit and see if the suction is sufficient from the power tools.


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## Holbs (Nov 4, 2012)

When I built my baffle ( http://lumberjocks.com/projects/98274 ) , I sure learned alot about air movement, cyclone, CFMs, baffle chamber, baffle material, etc. It was a very fun project. My dust collector is a 3HP. Did notice a slight drop in CFM after the baffle, but who cares  Negligible.


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## CharlesA (Jun 24, 2013)

A brief update. I was googling different designs and found the advice that the intake into the baffle should be about an inch above the baffle. I had it right on it. So I changed that and it seems to have made a difference. 95% is staying in the barrel and I would say suction is not only down 10-15% from before. Much better.


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## RobS888 (May 7, 2013)

Any pictures Charles?


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## CharlesA (Jun 24, 2013)

here are a couple of pics. When I do shop jigs, etc., I don't go for aesthetic points. I'm trying to finish as quickly as possible in order to make things I enjoy making. I re-used the box separator lid.


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## OSU55 (Dec 14, 2012)

I do find the Thien baffle doesn't capture really fine dust. I did a project using MDF with quite a bit of sanding, and needed to clean my filter afterwards. Typically with the planer, TS, and router hardly anything makes it through - I don't even see anything in the lower bag, but there was a significant amount of mdf dust. It wasn't a surprise, I didn't expect the separator to catch it.


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## redSLED (Mar 21, 2013)

After Thiening your pictures, I am humbly baffled.


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## RobS888 (May 7, 2013)

Thanks Charles,

I have a similar barrel, but I'm planning on making a tophat version, so I have to empty it less often.

My wife makes a massive amount of chips and dust with her lathe. We filled the barrel 7 times last year. I know because we had 7 of the big paper leaf bags full of chips and dust that I put into paper lunch bags to burn in our fireplace insert. They burn fast and hot. Throw 5 lunch bags in and then 20 minutes later nothing left of them.


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## CharlesA (Jun 24, 2013)

I didn't do a tophat for two reasons:
1) it was a lot more work. because I already had the lid with plywood backing on top and bottom, I could make this in a short period of time. 
2) I don't really like dealing with more that 30 gallons of dust/shavings at a time I discovered soon after I got this barrel.

I ended up cutting out a 4×6 rectangle out of the barrel about 1/3 down from the top and covered it with lexan, so I can see when it needs emptying.

BTW, because of the window I can see the airflow in the barrel, and it is a pronounced cyclonic flow.


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## RobS888 (May 7, 2013)

I'm doing some testing right now to see if 2 4 inch connections to/from the barrel will work. So the other day I had 2 4 inch lines going from the DC to the barrel and I was reading the CFMs being puled into the 2 outlets and they were both around 250 CFMs. Because I hooked the DC up to the 2 connectors with elbows inside the barrel it started pulling a lot of material from the barrel and I saw the cyclonic action in the bag under the DC. I was surprised at how many times it actually went around. There appeared to be a spiral going past my view every 8 inches. Your pictures helped me determine I should have hooked the DC to the inlets without the elbow. So tonight I will test it that way.

I'm pretty encouraged because using one line with branches, I got about 120 CFMs at my wife's lathe, during testing I get 220. I'm going to replace the piping, so it goes directly to her lathe instead of branching along the way. She will get one 4 inch line from the barrel and I will get the other.


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## CharlesA (Jun 24, 2013)

Hope it works for you, Rob. Wants I got mine "tuned," I'm really happy with it. I was surprised how much difference some little things make. I put some foam insulation on the outer 120 degree portion so it would be close to airtight against the barrel.


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## CharlesA (Jun 24, 2013)

Today I cut 24 feet of 8/2 QSWO on the bandsaw. Here is the dust inside the saw after that. I have both the 2" and 4" ports connected to the system by a WYE.


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## RobS888 (May 7, 2013)

> Today I cut 24 feet of 8/2 QSWO on the bandsaw. Here is the dust inside the saw after that. I have both the 2" and 4" ports connected to the system by a WYE.
> 
> 
> 
> ...


Awesome, just got home with new pipe and connectors. Going down to start tearing down old one and installing new pipes.


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