New HF/Thien/Wynn DC -- Expectations/Disappointments?

[Danny Thompson]

My variation of the Harbor Freight / Thien Baffle / Wynn Cartridge Filter Dust Collector Mod went into service last night. I'm not sure what to think. Maybe my expectations were too high? Please help me reset my levels. Two disappointments:

1. The first task for the new beast was to clear the table saw cabinet. To my surprise, the DC only cleared the 2-3 inches immediately in front of the port. The 3-4 inches of dust on the rest of the cabinet floor didn't budge. The DC was only able to pick up the remaining dust when swept toward the port. Is that to be expected? (A ShopVac can do that well.)
2. The only apparent airleak was a slight chimney effect where wrinkles occurred because the collector bag exceeded the ring size. This occured even when the clamp was cinched as tight as possible. Again, expected? Do you have any suggested remedies?

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Details:
Dust Collector: Harbor Freight (Central Machinery) 2 HP Industrial 5 Micron Dust Collector

• Assembly was a bit of a pain because the instructions did not match the provided parts. Midway through the assembly, it appeared some of the hardware was missing. Upon closer examination, it was clear, the instructions were wrong. The main problem was the instructions called for nuts in places where the parts were pre-threaded. Everything had to come apart, the instructions hit the trash, and assembly-by-wits came into play. In the end, there was adequate hardware and everything went together well.

JP Thien Baffle: Internal; S2S hardboard attached with L-brackets

• The three support posts provide convenient attachment points for the internal baffle. The holes in the L-brackets from Lowes had to be enlargened to accommodate the support post mounting bolts (M-8 x 1.25). The bolts screw into threaded holes in the main assembly. There are two bolts per support. For clearance reasons, the bolts that will attach to the baffle must be in place on the L-bracket before it is installed, and the L-brackets must be installed to the bottom support bolts before the top bolts are installed. A nylon lock nut secures the L-bracket to the bottom support bolt and a lock washer and nut (whatever size you have available) secure the L-bracket to the baffle. Notice, in this case, a bit of strap bridges the L-bracket to the attachment point on the slot side of the baffle.

Wynn Environmental Cartridge Filter: Model C1425C; MERV 15 Nanofiber; the same one used in the FWW article

• Because of the internal baffle, Dick Wynn suggested the shop-made donut method of attachment would be better than the hook-to-cone method used for pre-separator applications. The reason is, with the baffle in place, the hooks would be inaccessible. Instead of going with the two-donut model in the FWW article, a single donut (19" OD / 14" ID) fit quite snuggly in the collector ring. Because the collector ring was out of round, and because of the snug fit, it took several parallel clamps to press the donut in place, then some swift blows of the mallet to fully seat it. A few coarse 1 1/2" in screws lock the seal between the cartridge and the MDF.

Rockler 10' Flexhose

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[David Kumm]

You are pushing a rock with a rope. Any dust collector lacks the cfm to pull air much beyond an open port. The area expansion is a killer. that is why a good hood channels directly from the source to the port. My 7.5 hp collector won't totally clear my 3x3 Rockwell saw base. When you try to pull dust several inches or a foot away you need lots of cfm. That is why shapers need such large collectors if running big cutters. the cut is 10" away. Table saws are generally pretty bad unless they have a shroud around at least the bottom half of the blade that exits directly into a hose. Dave

[david brum]

One effective approach to collecting from the cabinet is to tilt the floor. You add a thin plywood sub floor, tilted toward the collection area. The steeper you make it, the better your collection will be. It also serves to reduce the volume of area you're trying to collect from. It's probably not as good as a shroud or bigger DC, but for sure an improvement over a flat floor.

You'll also get a noticeable improvement if you ditch the 4" hose in favor of 6" hose. You might want to do some research on this site to make sure your DC can handle it ( I'm pretty sure it can) but you'll move a lot more air.

[Ryan Mooney]

1. The only apparent airleak was a slight chimney effect where wrinkles occurred because the collector bag exceeded the ring size. This occured even when the clamp was cinched as tight as possible. Again, expected? Do you have any suggested remedies?

Expected. I just put a ring of stick-on door seal around the ring and then clamp the bag down onto that. I also replaced the stock bag with one of the Wynn bags which fits a bit tighter. Its certainly not perfect, but no visible leakage. I've also seen folks put an inner tube around the ring and other "soft" things to sqish the bag into.

You'll get a smidge (technical term) more oomph out of it if you replace the impeller->ring assembly with smooth pipe (5" stovepipe is commonly used) and possibly do like some of us and elevate the impeller so its a short/straight shot into the ring. (It still won't clear your Ts base though).

The main difference(s) between this and a shop vac is that you have ~3-4x the CFM (something like David's 7.5HP would be closer to 10x in vague handwavy numbers) moves more air, but generally at a lower velocity. In theory this means it should clear some more dust from the saw base in use (because the dust is already airborn), but once its settled you are definitely fighting an even larger uphill battle. In practice you rapidly start hitting hard walls of physics: http://en.wikipedia.org/wiki/Inverse-square_law which limits the velocity of the air at any distance from the opening to some small fraction of the pipe velocity and thus your observed behavior.

[Danny Thompson]

One effective approach to collecting from the cabinet is to tilt the floor.

Thanks for the suggestions so far. Interesting, the table saw in question has a funnel-like bottom that tilts from 3 directions toward the chute.

[Jerome Stanek]

The Thien is a pre separator you shold have it on a trash can to collect the heavies before they go through the fan and into the main bag.

[Sam Stephens]

The Thien is a pre separator you shold have it on a trash can to collect the heavies before they go through the fan and into the main bag.

yes. i've seen this design, but wonder how effective it really is vs no baffle. do that many large chunks not drop out of the air stream in this configuration that necessitate the baffle. I have a 1.5hp delta dc/ wynn filter/ thien baffle pre-separator and it does quite a good job at clearing my TS cabinet (also tilts toward the dust port). Out of curiosity, is the dc more effective w/o the baffle i.e. just utilizing the better air flow surface area from the wynn filter. Also, what about the ~90 degree turn on the hose from the impeller to the baffle/bag. Would a more gentle curve make a noticeable difference here.

Sam

[Wade Lippman]

Out of curiosity, is the dc more effective w/o the baffle i.e. just utilizing the better air flow surface area from the wynn filter. Also, what about the ~90 degree turn on the hose from the impeller to the baffle/bag. Would a more gentle curve make a noticeable difference here.

Sam

As far as I know, no one has ever tested dcs with and without baffles. (except for the Jet ad, which is pretty dramatic...) People who use them say they don't affect air flow, but that isn't a test. Try it and let us know what you think.

A gentler curve with smooth pipe would probably help a lot. Probably not worth the expense though.

[Ryan Mooney]

As far as I know, no one has ever tested dcs with and without baffles. (except for the Jet ad, which is pretty dramatic...) People who use them say they don't affect air flow, but that isn't a test. Try it and let us know what you think.

A gentler curve with smooth pipe would probably help a lot. Probably not worth the expense though.

EDIT: This is for a top hat.... the baffle should be quite a bit better, but yes please measure it

There is a thread on Phils baffle board jpthien dot com
Topic (a page or so of threads back): 5", Rectangular Inlet, Bellmouth Outlet with Air Straightener, Top Hat Separator
Page: 7
where someone measured about a 40% hit on his unit with the baffle vs without. I would be surprised to see anyone saying that there is zero performance hit, that fly's straight in the face of physics; the obvious tradeoffs re filter load, etc.. aside.

I changed so much on mine that I couldn't say even annecdotally what the performance delta might have been (replaced bag with wynn filter, moved from curved flex pipe to short/straight 5" between impeller and ring, etc...), but that measurement seems fairly close. The smooth pipe is a pretty cheap mod, as noted above stove pipe works well.

[William C Rogers]

Wade

FWW has an article in the March April issue where they tested various separators (Thien, trash can, super dust deputy). They were doing a filter test will the various filters (Wynn, Onedia, and Grizzly). Supprising the Thien baffle had lowest initial cfm loss, however the dust deputy maintained a constant cfm. The trash can lid separator did not have enough cfm from the start. They tested 3different filters and the Wynn won out as far as taking the longest to clog. They also tested without the separator and clogged the filter with one bag of collection. Wynn was the least cost, but you needed be creative attaching it. I thought it provided some good information, but after the Wood cyclone test was dissected Here I am sure there may be a different opinion.

[Phil Thien]

There is a thread on Phils baffle board jpthien dot com
Topic (a page or so of threads back): 5", Rectangular Inlet, Bellmouth Outlet with Air Straightener, Top Hat Separator
Page: 7
where someone measured about a 40% hit on his unit with the baffle vs without. I would be surprised to see anyone saying that there is zero performance hit, that fly's straight in the face of physics; the obvious tradeoffs re filter load, etc.. aside.

I changed so much on mine that I couldn't say even annecdotally what the performance delta might have been (replaced bag with wynn filter, moved from curved flex pipe to short/straight 5" between impeller and ring, etc...), but that measurement seems fairly close. The smooth pipe is a pretty cheap mod, as noted above stove pipe works well.

The test to which you're referring was not a test with and without baffle, but a test with and without a discrete separator which featured a baffle.

Any separator will introduce resistance which results in lost airflow.

However, adding a baffle to the ring of a DC (thereby turning what wasn't a separator INTO a separator) introduces smaller losses than a discrete separator.

How is this possible?

Well, the vast majority of losses are coming from the resistance of spinning air.

The air in a typical DC ring is already spinning. You already have quite a bit of resistance because you're already spinning the air mass. What we're doing is adding a brilliantly thought-out wall (my baffle) on the bottom of the DC ring, which concentrates the spinning above the baffle. YES, this does increase resistance.

But nowhere near 40%.

And as FWW's test demonstrated, adding a baffle keeps the filter cleaner, longer. So you pay a little up front (in terms of resistance) and gain longer periods between filter cleaning, and greater filter longevity.

[Phil Thien]

Wade

FWW has an article in the March April issue where they tested various separators (Thien, trash can, super dust deputy). They were doing a filter test will the various filters (Wynn, Onedia, and Grizzly). Supprising the Thien baffle had lowest initial cfm loss, however the dust deputy maintained a constant cfm. The trash can lid separator did not have enough cfm from the start. They tested 3different filters and the Wynn won out as far as taking the longest to clog. They also tested without the separator and clogged the filter with one bag of collection. Wynn was the least cost, but you needed be creative attaching it. I thought it provided some good information, but after the Wood cyclone test was dissected Here I am sure there may be a different opinion.

I would just like to add that while I was thrilled by the coverage in the FWW article, I think the baffle would have performed better had they not used the Jet unit, where the clear bag attaches using the snap ring. The snap ring and bag tend to create a small ledge which can interfere with separation.

They had initially thought they'd use a General International (where the bag attaches to the OUTSIDE of the ring). Then they changed to the Jet with the snap ring. I communicated the problematic nature of the snap ring, but ultimately it was up to them.

Quite honestly, I think it is amazing how well it worked given the snap ring.

Again, I don't want to seem unappreciative to FWW for the coverage. Just pointing out an important point.

[Jim Andrew]

About the tablesaw, you need to get the cabinet cleaned out so the DC can do it's work. My uni builds up once in a while, usually because of a piece of wood or 2 in the inlet. Of course my uni has only a 4" port. Sure it would work better with 6, but have a Y in it and a 4" port on my shark guard. I just use a narrow strip of wood to reach down through the insert opening to poke the dust loose with the dc running to clean it out.

[Robert Payne]

HF DC cannot produce adequate airflow to move sawdust in your saw and the combination of ten feet of 4" flex and a separator doomed you from the start. You'll need 6" ports and a short straight run of 6" duct to a sawdust producer like your tablesaw; save the separator for your planer or jointer to catch chips but always use larger pipe and minimuze the airflow-robbing flexible duct (better to move the DC closer and use a short duct run).

[Danny Thompson]

Thanks for the tips. Sounds like the steps that won't cause me to reconfigure my TS are:

1. Switch to the Wynn bag and add a soft rubber sealing aid (inner tube).
2. Shorten the 4" flex hose run.
3. Replace the 5" flex hose run with rigid metal pipe.

Then try again with a clean cab as a starting point.

I'll do that and report back.