Hey & thx to all who've offered their 25 cents so far! If it makes any difference to what anyone might suggest, I'll give a bit more of my system. (Should have done that initially) I've just newly aquired a Grizz 3hp cyclone. Plan to run 6" mains, 6" drops, and then either 5" or 6" hose to my table saw, jointer, planer. (I'll prob be running more than this to the drill press, edge sander, router table, bandsaw etc) but specifically these machines are my mains. My unisaw is older in that it has the rectangular shoot (no port) where the sawdust just slides out onto the floor. My General 350 (also older) ... kinda like me has no port at all on it. I'll try the metal HVAC shop approach & bring along my 6" spiral hose to see what they might be able to make. Just a shame no-one makes a 5" or 6" PVC "toilet flange" kinda thing that I could just sheet metal screw on after I enlarge or make a hole. That pic of the circular metal flange with the tabs looks pretty good. Maybe I'll print that & take it to the HVAC shop. Odd isn't it that my General (Canadian model) 350, doesn't have a port at all on it don't 'cha think?