This post by Tom tickled my curiosity. Yesterday I spent a few hours to turn an old bucket into a miniature cyclone. I haven't had time yet to test it with my (tiny) table saw or other power tools. I just tried it on the contents of a bag of sawdust from my shop vac. I was positively surprised by how effective it was. All sawdust in the bucket, none appeared to make it into the vac.
Here's some pics of my miniature version. I scaled it down to the size of what materials I had available and what fits my saw and shop vac.
Detail: bucket edge.
At this time I have not yet made something that firmly closes the bucket. I routed a small circle in the top that matches the ridge on the bucket. Suction alone keeps it closed when the vac is running.
What's inside: the plumbing.
Hook it up to the vac for a test run.
The white bowl was filled with a vac bag of saw dust. All of it ended up in the bucket, none seemed to make it to the vac.
No final verdict yet as I have to see what it does on the table saw and other tools, but so far I'm pleased with initial tests. Spend some time on this if you don't do nothing yet about dust. It is simple, cheap and appears to be quite effective. Curious to hear what others do about dust.