Second Separator done - minor design tweaks.

[NCTinkerer]

My first separator was just thrown together without much finesse.  I just wanted to be sure I could make it work.  It works really well.  Not content to leave well enough alone, now I've got the second one done.  I tweaked the design a little.  I switched to 1/2 inch plywood for the top and bottom.  Since I'm using a 2.5 inch Shop Vac hose for the inlet,  I tapered the inlet port so that the rectangular cross sectional area where the air enters the cyclone area matches the area of the round inlet.  In my case the transition is from a 2.25 inch round hose to a 1.75" x 2.25" rectangle.  I also increased the outlet port diameter to 3 inches ID.  I know I'm messing with a tested design, but in my case I have my Shop Vac sitting directly on the top hat.  It seemed to me that having the 2.25 "outlet added additional resistance.  I also thought that by increasing the outlet size, I could reduce air velocity at the outlet and maybe pick up less of the fine sawdust.  Probably should have just left it alone, but that has never been my way.  I should be able to test it tomorrow.

[NCTinkerer]

This new separator works even better than the first.  There is more suction.  It is quieter.  And, I think it has better dust separation too.  I know it's unscientific, but with the first separator I could vacuum off my floor mats without them sticking too much.  Now I have to stand on one end to clean them off.  The dust separation seems better, but it is hard to tell because both of them work great.  So, I'm ready for an extended test.  I have inserted the new .3 micron filter and will go back to my woodworking knowing that when I'm catching sanding dust off the lathe or cleaning up the shop, I'm not just stirring the fine stuff around anymore.  I may have to re-prioritize some money and get one of the cheap 2 HP dust collectors now that I know it could be made to work as well as an expensive one.

Here are pics of my test and a shot of the filter label.  I'm really happy to get it.  About 20 bucks at Lowes, what a deal.

About a gallon of mixed sized dust, all but a puff or two of really fine stuff stayed in the can.

P.S. Phil, that small donation I made was some of the smartest spending I've done all year.  Thanks for your ideas.