Impeller size?

[keith ouellette]

I am thinking about a used DC. It is a 3hp motor and the guy says it delivers about 2500 cfm (don't know where he got the number from) and it has about a 14" impeller.

Does that sound about right?

[Chris Padilla]

What kind of DC is it? What vendor/brand name? What size motor on it?

My shop built Bill Pentz cyclone DC has a 14" impeller and is driven with a "5 hp" Leeson motor. It really sucks but I don't have any numbers.

Ignore his CFM comment as this number depends on a great many things.

[Chris Damm]

I have a 3 HP jet twin bag DC and it's rated at 1900 cfm. It's probably a little less than in a real world setting. I believe it has a 14" impeller.

[keith ouellette]

What kind of DC is it? What vendor/brand name? What size motor on it?

My shop built Bill Pentz cyclone DC has a 14" impeller and is driven with a "5 hp" Leeson motor. It really sucks but I don't have any numbers.

Ignore his CFM comment as this number depends on a great many things.

It is also a Leeson motor model number L5k34fk43 and I did mention it was a 3hp. They did not mention the brand of the DC other than stating the motor type and maker

I does sound like a 14" impeller is right for the motor side.

[Scott Wigginton]

Ditto the others, Powermatic 3 HP with 14" impeller rated at 1900 CFM.

[Chris Padilla]

14" is probably fine, Keith, and sorry that I didn't notice you had stated the motor power.

Is the DC a cyclone? (yes, I double checked your first post to make sure you didn't tell us this already! )

Without getting into the details, however, not all 14" impellers are created the same but I suspect this one is probably ok. I think a lot of the larger cyclones are using 15" and larger impellers.

check out my DC build thread...you can see a pic of the impeller and housing.

[Chip Lindley]

HI Keith! My trusty ol' Oneida is a 3hp Leeson and 15" impeller, FWIW. While obcessing over whether 14" is big enough, remember that the design of your ductwork for proper flow is paramount to a successful DC system!

While you are designing, check out the latest in Molybdenum interior powder-coated ducting to decrease molecular friction, and a very experimental new DC technology of injecting 8 percent helium into the shop atmosphere so that the DC system pushes *Lighter Air* thus increasing efficiency for any given impeller size.

Geez, your 14" could easily rival my 15", BUT you may talk like a *chipmunk* for some considerable time after departing the shop!

[Rod Sheridan]

HI Keith! My trusty ol' Oneida is a 3hp Leeson and 15" impeller, FWIW. While obcessing over whether 14" is big enough, remember that the design of your ductwork for proper flow is paramount to a successful DC system!

While you are designing, check out the latest in Molybdenum interior powder-coated ducting to decrease molecular friction, and a very experimental new DC technology of injecting 8 percent helium into the shop atmosphere so that the DC system pushes *Lighter Air* thus increasing efficiency for any given impeller size.

Geez, your 14" could easily rival my 15", BUT you may talk like a *chipmunk* for some considerable time after departing the shop!

Molybdenum??????? DOH!!! That's what went wrong, I used a ceramic coating with teflon covering.

Regards, Rod.