CFM loss when reducing hose sizes.

[Larry Frank]

I can not verify others but the Oneida published performance curve was close to what I measured. Taking accurate numbers is difficult. I tried to do a good job but know that at best I am likely +/-10%.

Not only are some mfg numbers over estimates but people using a fan anemometer are way off.

[james manutes]

Over the years , I've had 3 1HP collectors . Penn State , Rikon , and an old Craftsman . The Rikon was the worst , the other 2 fine for what they are . Impeller's 10" in size can only do so much . Putting them with a single tool only is about all they can handle , in the right situation . Hoping for better results is just not in the cards . Using 2.5 " pipe is a waste of time .

[Curt Harms]

Over the years , I've had 3 1HP collectors . Penn State , Rikon , and an old Craftsman . The Rikon was the worst , the other 2 fine for what they are . Impeller's 10" in size can only do so much . Putting them with a single tool only is about all they can handle , in the right situation . Hoping for better results is just not in the cards . Using 2.5 " pipe is a waste of time .

2 1/2" pipe is fine --- when used with a shop vac. I do have a 2 1/2" hose connected to a router table fence and dust collector. It isn't practical to put a larger fitting on the router table fence. It collects chips pretty well but the chamber the fitting is attached to is pretty small and tight. Using a 2 1/2" hose for something like a stationary belt sander or table saw base? I would have low expectations.