Hi Cabby,
Total dust removal from a scroll saw is extremely hard to achieve as dust is ejected from both the top and the bottom of the cut.
Some saws have dust extraction ports but this only deals with half of the problem.
I cut a lot of MDF and was very concerned when I read that the smallest particle the human eye can see is about 10 microns.
Dust that is harmful to us the most is the dust we can't even see !
As a point of interest, many freestanding workshop dust extractors only filter down to about 10 microns which means that harmful smaller particles are being recirculated through the extractors dust filter bag and back into the workshop. So, if dust is a concern and you don't mind paying a bit more, go for an extractor that filters out down to 1 micron.
I personally extract my dust straight through an outside wall as it's far more efficient with no chance of dust being recirculated through dust filter bags.
I originally had just a single heavy duty 'Squirrel' fan about 18 inches away from my saw that was extracting through the workshop wall. This works well and extracts a lot of air but at certain times of the day when the sun streams through the window I noticed not just large dust, but fine dust coming off the saw that's not noticable under normal lighting conditions.
I guessed what I was seeing was the fine dust we can't see but in a smoke like form.
This spurred me on to install 2 more extractors. One I put through the wall to the right of the saw and the other is right next to the saw table pulling the dust straight off the table and shunting it to the wall extractor.
The extractor close to the saw table came out of a kitchen cooker hood and shifts around 550m3/h. This set-up works well and when the sun streams in I can now see the smoke like dust being extracted very efficiently.
It's not my intention to scaremonger here but if like me you value your health, please don't rely on your machines dust port or just a single freestanding workshop extractor. In my opinion they are nowhere near up to the job when it comes to the fine dust ejected from a scroll saw or any other machine that generates fine dust.
I still get general dust settling from other machines in my workshop and every so often when the wind is strong, I open both front and back doors and blow it through using the blower function of a 'Hoover' type extractor I have attached to my Radial arm saw.
Hope this helps,
Alan