The dust created by Kapex is nothing different from other miter saws. It might be getting too technical, but here is something I drawn up to explain it.

The saw dust travel in direction perpendicular to the tooth angle. Right after the cut, the initial speed of the dust is very high so that it appears that all dust are at Y direction, and the X direction is barely taking any effect, but it still there. So the dust is flying out. Unless the dust shroud very close to the cutting point and wrap around saw blade (Kapex is designed better than the rest), the dust will fly out.


The finer dust are very light and very easy to change the travel direction causing by air movement (dust collection), so they got sucked in (those are our major concern). The larger particles in the other hand are not very easy to change the direction will hit the dust shroud bounce out or fall onto the cutting table.
The more air movement (DC) the better chance to get all the particles. That's the reason for D36 hose instead of D27 because of the size of the air pass cross section. I used Shopvac with 2 1/2" hose to increase the volume of the air flow, but limited by the opening size of the Kapex dust port. (I think it's way to boring to show any air pressure and aerodynamic calculation so I am skipping that part
![Smile [smile]](http://festoolownersgroup.com/Smileys/default/smile.gif)
) Thus, technically you can only do so much.
But a simple bigger shroud with do much better job.
Kapex DC ShroudI did some work for my other miter saw too. The above thread showed the 12" Ridgid, it did a better DC job than Kapex without the shroud modification. Below pictures were from the 12" Bosch SCMS before I had my Kapex 3 years ago, it was as accurate as the Kapex. I used the Bosch to cut stuff indoor with CT22 or Shopvac hooded up, never had problem.
The reason for the Kapex is because the weight, size and space needed behind the saw for shop set up, not because of the DC capability, and 12" Bosch glider just too big and heavy for any mobility consideration.




