Baffle idea.

[phil from seattle]

I have build several Thien baffle separators and really like being able to adjust the design to fit the needs. I have a big one on my shop dust collector and one on a small mobile cart I use a lot.

Anyway, I'm finishing up a 4'x4' CNC router. It will have a dedicated dust collector and I'm going to make a separator for it.  But I got thinking about how to reduce turbulence by have a straight inlet. I can cut arbitrary/complex designs on my CNC router and thought this design might be a step in that direction. This one is relatively small for a shopvac but I would size it up for the CNC DC. The top surfaces of the bottom ring and baffle would be coplanar, by the way.

A refinement of the design could be to use another strip of polycarbonate to support the outside edge of the 1/2" baltic birch top and bottom to make it look a bit more finished.  Also thinking about integrating the baffle into the bottom.  There may be a way to get rid of the supporting bolts which would serve to reduce turbulence and wind resistance (if that is the correct term).

I am interested in anyone's thoughts on this.  Stupid idea?  Needs work?  Any gotchas?

[phil from seattle]

I see schrek's posts and they give me some improvement ideas.  Foremost is to add a bell output on top.  Super easy to make on a CNC router. Thanks!

Also I was planning on 4" ducting throughout - from the dust shoe on the spindle to the DC input manifold. Maybe a bell manifold to larger input on the DC if necessary. I haven't selected the DC yet, leaning towards a Griz 1.5 HP model with 1250 CFM (yeah, I know CFM numbers a kind of a fantasy). Of course, it is currently out of stock.  Sigh.