A friend with that saw built a table for it with a table top that is exactly the height of the saw's table, shimming the saw slightly to make it exactly even. The open bottom spills into a box with a slightly slanted bottom and a 4 inch dust port on the back hooked to a 2 stage dust collection system (separator bin, blower, final filter), This stand is set up in a semi permanent spot, which allowed him to fix a 2x4 to the ceiling that drops down a foot or so behind the blade. He used 4 strips of aluminum to move a dust collection hood up and down over the blade. The dust collection hood could be commercially made, but he made his with a wood top and plexiglass sides, curved in the front to pass over the wood being cut. The dust collection 2.5 inch hose runs from the back top of the hood, up the 2x4 then off to the side to connect with a Y connector that joins the hose from the 4 inch port below. The parallel aluminum arms have a counterweight behind the 2x4 and a screen door spring pulling down lightly that lets the hood ride lightly on the stock being cut. This rig is really simple but depends on the saw being set up pretty much permanently in one spot. If you want to keep the saw on the portable rig, you'd have to find a way to reset it in exactly the same spot every time you use it in the shop, and put a bottom plate with dust port on it. I have a reduction hose that ends with a 1 inch PVC pipe for reaching into and cleaning out the sawdust that gets stuck in them mechanism.
I agree that this kind of setup is all about air flow, not necessarily vacuum pressure. Saw a very interesting home built dust collection system recently; instead of using a standard blower (Harbor freight, Rockler for example), the guy put a squirrel cage blower at the top of a large box. The intake is in the middle on one side into about a 6 inch chamber with a divider in it to deflect the air flow and debris down. Below that chamber is a well sealed, pull-out drawer that heavier debris falls into. An opening on the other end of the chamber above the debris drawer, pulls air up then across and through a couple of replaceable or washable filters, each mounted between chambers with room on the bottom of each filter chamber for dust to settle. Doors on this section allow for filter cleaning or replacement, and acces to cleanout any settled dust.
By the time the air reaches the big, commercial blower, its pretty clean and it is ported outside. There are doors for the middle section where the filters are so he can clean them out with a shop vac. This thing was maybe 3 feet wide and 6 feet tall but only about 16 inches thick, so you could mount it on a wall and port the blower output through the wall to the outside. If it was still spitting sawdust, you could add more or finer filters inside or outside to catch it. As I recall, the guy who made it actually ports the air back into the shop, which would be OK only if you have filtered out ALL of the finest dust or are a zealot about wearing a respirator at all times in the shop.
I have an oversized evaporative cooler that cools our 1800 sqft house and replaces the air in the house completely every couple of minutes. That would be overkill for a dust collection system, but there are some smaller but heavy duty blowers on Amazon that have incredible airflow specs that would fill the bill. I bet it would only take a day or two to build something like this with a couple of sheets of 18mm ply. The blowers were about $200 bucks for a high volume model. Without a lot of airflow there is no way you can keep the dust down with a portable or open bottom table saw.
Hope these possible solutions are helpful. I'm a throat cancer survivor and the warnings about sawdust as carcinogens and the ultra fine and invisible dust's causing serious and permanent lung damage made me very careful about dust collection.
One other thing I'm doing is adding a second, dust free finishing and storage shed so I can clear out the bottom 16 inches of floor all around the main shop. That will make it easier to clean up the dust that seems to drift into and permeate every nook and cranny. Dust collection is serious business and ignoring it will only lead to very bad health issues over the years. A ventilated mask is now standard for me, as well as an overhead filtering system to continuously remove that awful, nearly invisible airborne dust that is most damaging. Much as I'd love to just hang out with my tools, I'm only going in to work on projects these days. The new shed will become my get away cave, so I'm setting up power, insulation, finished walls, lights and extra double pane windows for my comfort. Even plan to paint the joint some cheerful yellow. I write a lot in my work, so there will be a small workstation there as well since it is in range of my wifi.
Thanks for putting up with the rant, I'm pretty fired up about this wood dust health issue.
Last edited by DesertRatTom; 10-11-2014 at 07:05 AM.
Reason: edit for clarity