A cyclone is definitely the way to go, but I think you will be up sizing the blower horsepower before long. You will probably also be having fits trying to get a leak tight seal on that metal trash can lid. Although metal trash cans are easy to find, they tend to be hard to seal the lid and seams when using them for this purpose. I went with a metal grease barrel because the barrel has welded seams and a smooth top lip to seal to the lid. When running, any leak in the hose connection or barrel below the cyclone will significantly reduce the efficiency of your system, and it will also result in considerable amounts of dust and chips getting past the cyclone and into your filter bag. A cyclone depends on no up air flow from below or the dust and chips won't fall out the bottom of the cyclone into the collection container and some will end up getting past the cyclone.
I used some 1" wide "closed cell" foam Weather stripping applied where the lid of my collection drum and the drum top edge come together with the sticky side of it attaching it to the lid. I carefully cut the two ends of the Weatherstrip at the same time using a razor blade, so there is no leak between them. The vacuum pulls the lid tight to the barrel when it's running, so I haven't needed any mechanical fasteners, just gravity keeps the lid on when the vacuum is turned off. I used a smoke generator held close to possible leak points to see if I had any leaks after I had assembled my system. They sell smoke detector test spray that works well for this. A smoldering piece of clothes line rope works, but don't use it if you have any dust or wood chips in the system because a spark from it might be drawn in. The smoke spray is the safest and most reasonably priced way to test for vacuum leaks. You need to spray it near the possible leak and then watch to see if any is being drawn in. Use good lighting so you can see if this is happening. Leaks in the joints of your system can be found the same way. The HVAC guys use a rubbery paint-on sealer for duct leaks, or you could just use the silver duct tape and carefully apply it to avoid wrinkles which might leak. Any leak in the pipes between your machines and the cyclone will reduce the vacuum level at your machines. With only a 1 1/2 hp system you can't afford to have any leaks or efficiency losses.
Central North Carolina
Last edited by CharleyL; 12-29-2018 at 11:30 AM.