Thein baffle vs drop out box vs cyclone.

[Robert Wolf]

I'm looking for some advice on what seperator to choose that will have the least static pressure loss. Fines are vented out the window. I have a Thein baffle but the static pressure loss created severely hinders large chip collection on my table saw. Seeing as I have a jointer and planer being shipped I need to fix this soon. Harbor freight 2hp DC.

Im not too concerned about scrubbing. As everything else will vent outside. Could I just remove the Thein baffle altogether and just use the minimal cyclone action of the harbor freight top hat to separate the large chips into the can ?

326865

Sorry its sideways. I'm going to be switching to a larger ducting when I get the money. I had some sewer pipe left over from fixing my septic. So thats what I went with.

Right now the opening to the baffle is 1 1/2" thick. Could this be negatively effecting SP loss? I don't want to remake the baffle if I don't have to. Removing it would be the cheaper/ easier option for me.



-Robert

[glenn bradley]

This question comes up many times. Placing any "after-market" separator on a DC that is not designed for it places a huge hit on your airflow; that's just what happens. This includes cyclone add-ons. They are a band-aid but, often a necessary one. I have used a few variations in the past. A cyclone system where the blower is designed with the separator (cone) in mind is your best bet. A blower that starts our with enough oomph to tolerate the hit of an add-on is your next best bet. (Side note - never use a sharp 90* turn like in the pic, its a flow killer).

I did away with the separator on my small DC with a 4" inlet as the other option was to do away with the DC :). Being able to vent outside gives you many more options. I would experiment with the amount of separation I could live with. The less impact on the flow, the better your collection but, this is offset by the amount of spoil getting past the separation device. I moved to a properly sized aftermarket bag (http://www.americanfabricfilter.com/air-to-cloth-calculator.php) and this helped tremendously. I still eventually removed the separator and shifted this DC to jointer-only service.

[Steve Peterson]

I wonder if the problem could be the restriction in the pipes more than the Thein baffle. The Thein baffle causes the air to make one large 18" radius sweep and one more direction change inside the can to pull the air upwards. I believe that these are less restrictive than the small 90 degree elbow above the baffle.

Can you mount the blower directly on top of the baffle to eliminate the elbow?

A jointer and a planer will produce much more sawdust than a tablesaw. Plus, they are more likely to produce long strings, so you might need to keep the baffle since all remaining sawdust has to go through the blower.

Steve

[paul cottingham]

I added a "Thien style" tophat separator. I lost airflow, but honestly, that is more than offset by the fact i never have to empty the bag on my separator. I plan to eventually vent the dust outside, and not use the bag and filter.

[Bruce Wrenn]

I have both Top Hat (built the very first one in Nov 2008,) and cyclone. Because cyclone is tucked in back corner of shop, and I use planer and joiner on slab out front, I catch chips where they occur, instead of in cyclone in back. I think you are saying inlet is only 2 1/2" in diameter. If so that's where your problem is.

[David L Morse]

The collector ring is a centrifugal separator with or without the Thien baffle. The baffle just reduces scrubbing. According to my measurements a Thien baffle added to a HFDC put about a 2" hit on static pressure at 500CFM. With only 7.5" SP available to begin with that's a noticeable reduction. Lose the baffle. In fact, you could lose the collector ring and just use a drop box for even less pressure loss.

However, as has been pointed out, most of your restriction is likely in the plumbing on either side of the blower. The 4" with the tight 90 on the intake is the worst offender. The tight bend on output flex doesn't help either.