Thien baffle featured in FWW!

[memilanuk]

Got my copy of FWW today... flipped to the 'Soup up your DC' article, and when I saw the testers angling what looked a lot like a Thien baffle up inside the separator ring of a Jet DC I thought "those sneaky snakes, ripping off Phil's design!"  Soon after I saw they gave credit where credit is due, naming it a Thien baffle, etc. 

I was a little disappointed that they didn't seem to even touch on the possibility of using a stand-alone Thien separator, instead 'testing' two commercial units - a Super Dust Deputy, and a trash-can lid unit.  Bummer!

[alan m]

its great to see that these 'homemade"(yes homemade but very well engineered) ideas are starting to make their way into magazines.
i would love to see an article onbuilding  a top hat seperater. but it would have to be done by a true thien user. even using all the extra developments that have built on phils design.
then have a shoot out.
set up each seperater type conected to its own extracter. all the same extracter and proper filter. this should be a level playing field
then run  each seperater on a bunch on different machines.
planer/thicknesser
drum sander
spindlemoulder
bandsaw etc

do the same cuts on each in the same order. then measure the drum and filter

[memilanuk]

The more I look at their setup... it doesn't look like they have the baffle rotated quite right.  Looks like the port enters in the middle of the full-diameter section, not closer to one end.  Maybe I'm not looking at it right?

[phil (admin)]

That is pretty neat.  I tried calling around to find a copy of the magazine today but it looks like that edition won't hit newsstands until the 16th.

Looking forward to seeing what it has to say.

[RonS]

Phil, Check your PM's

Ron

[phil (admin)]

Okay I've seen it now and I can respond.  :)

I thought it was a very nicely done article.

Bill Peck from FWW had sent me an E-Mail last year asking if it was okay to write something about the baffle.

We talked (via E-Mail) a few times in January of last year, and then I heard nothing more.  I figured maybe they lost interest.  I was glad to hear they hadn't.

Now to cover a couple of points:

(1) Mr. Peck had originally said they were going to use a General International DC for the test, then subsequently said they'd be using a Jet.  I had mentioned to him that the Jet really isn't an ideal choice:

"Oh boy.  That snap ring on the Jet DC-1100 often creates a sort of ledge which interferes with separation quite  bit.  Not the optimum DC for a baffle mod."

The bag retainer on Jet units can result in a ledge around the perimeter of the ring, which obviously is going to interfere with separation.  For optimum separation, this area needs to be smooth and uninterrupted.

Units where the bag is clamped to the OUTSIDE of the ring will work better with the baffle.  That bag retention method on the Jet is the thing's Achilles' heal, IMHO.

If you have a Jet to which you'd like to add a baffle, do yourself a favor and get a big band clamp and move the bag to the outside of the ring.

(2) FWW seemed to experience filter loading (with the baffle) faster than what I'd expect based on feedback from other baffle users.  Of course, #1 (above) would contribute greatly.  Other factors can be the rate at which you feed debris, and the type of the debris.  So quickly stuffing fines into the hose is going to load the filters faster than slowly feeding chips.

(3) FWW said that when they cleaned the filter, the result was a pile of debris on top of the baffle.  They had to remove the filter and brush the baffle off to prevent this pile from just getting pushed right back up to the filter with the next run.

Removing the filter a lot would certainly be a pain.  A better option is simply removing the inlet air hose and reaching in with your arm and pushing the dust over the edge of the baffle.

But most of the feedback I get is one to two cleanings a year (from fairly heavy users) where they simply take the filter outside and clean it out.

I really think the key to superior performance is making sure the bag is clamped to the OUTSIDE of the ring.  I know it seems simple, but as Mathias Wendel observed in his video at woodgears.ca, a properly executed Thien separator removed more wheat flour than a high-end 3M Filtrete filter.  It does work very well, you just have to observe a few rules.  Rule #1 has to be no ledges.

All in all, I think the article was nice and very favorable.  Clearly the Thien baffle outperformed the other solutions in airflow until the filters caked, which required over 100-lbs of sawdust.  And had they moved the bag to the outside of the ring, I feel the results would have been even better.

[retired2]

I guess the good news is they at least gave you credit by name.  It's a shame they didn't use a setup where the baffle was not somewhat compromised.

I let my subscription lapse a long time ago, but I'm going to look for a copy at the news stand.  I think all of us who have built and benefitted from the Thien separator should send the editors a message suggesting they do a feature article covering all the common configurations such as the trash can lid and top hat.

[alan m]

i left my fww subscription last as well.
i fund it too full of historical builds and the same old stories over and over again
i just look through them now and see if i want to buy it

what issue  no is it . we are a bit off with the issues. there is a bit of a dellay at times.

have you a pic phil

i would like to see a proper build. maybe if they only borrowed one and tested it.
there are several  really good versions on here.

[phil (admin)]

It is Fine Woodworking #232.

[Woodcutter]

My first post here.
I saw the dust collector article in FWW, and Phil's comments.

I think it would be great to see some form of Phil's comments as a letter to the editor in FWW.

Just my 0.02   .

[coloradotrout]

I read the FWW article a couple days ago.  It's a decent tribute to "one of us" who came up with a brilliant idea -- and should have rights to it.

I made the baffle for the Jet a few years back.   It works well.  I use 6" sewer & drain tube to my tools, and then 6" flex to my homemade gates (taken from other online contributors).    So all 6" which I doubt FWW tested.   They probably stepped it down to 4", but if you read any of Bill Pentz's stuff (another great contributor to this hobby), you'll understand his argument for 6" end to end.   6" is double the area of 4", and so airflow is much greater than 4".   But with that increased airflow, getting particles to drop out of the air stream can be harder.  I have found my Thien baffle works well.   

I do have the issue with the Jet band for holding the lower bag in-place.   I may have made my "drop slot" a bit bigger, but there is some disturbance there for sure.   I'd really like to replace that lower bag entirely -- some simpler way to attach and remove the chips.  As far as attaching the Wynn filter atop, I think a couple, or maybe 3 even 4 bungee type cords could be strapped over the filter and down to the housing.  That should work for the case where the cone is continuous and the Wynn is slightly smaller diameter.   The turnbuckles that come with it, seem to be a hassle IMO.  A few strap would take seconds to unhook, etc.

Anyway, Phil --- seeing acknowledgement in FWW for your contributions was great.  Hopefully the mag does more of this in the future.