Newby wants to talk cyclones

[John Zimmerman]

I'm a newby on this net but was on rec.woodworking maybe 15 years ago and was one of the first members of the first neandrethal (hand tool group) on the net. I posted once on the spiral cutterhead thread but have also noticed a lot of dust collection, specifically cyclone, threads and was wondering if anyone here has built a Bill Pentz cyclone. Anyone interested in dust collection should visit this web site: http://billpentz.com//woodworking/cyclone/index.cfm.

Bill is a woodworker who has developed a lung disease and his passion is dust collection. He has become a student, designer and builder of cyclones and his web site must be hundreds of pages of everything you need or want to know about dust collection. I've built his first design and have all the pieces but am still in the process of putting them together (work, lots of travel and family stretch out these kind of projects). Anyway it should deliver >1400 cfm with a significant static pressure capability for an investment of less than $500.00 but lots of sweat equity. By the way, there is a feeling Grizzly ripped off his design with their latest cyclones, which means if they built them well they probably will work pretty good.

John Zimmerman

[Allan Johanson]

I've built his cyclone with the 5HP Leeson motor and 14" Sheldon impeller. I've also tested it with the proper equipment. Bill has done an excellent job and the performance is astounding. But just so you know you won't be getting a useable 1400cfm with 6" ducting. You'll need 7" for that. But then you'll have other problems with low velocity in that large duct if you aren't careful.

BTW, with 6" ducting and depending on the tool, you will probably get around 750-1200cfm depending on how restrictive the tool is combined with the length of the ducting. It can vary a lot.

If you want up to maybe 80 "free" cfm, make the exhaust be a full 8". Don't restrict it to 6" like suggested on his site.

Cheers,

Allan