Dust separator size?

[Kevin Begos]

I just bought the Woodcraft 4" dust separator, and wonder how large the collection can/box needs to be. I checked Phil Thien's site, too - don't see this addressed.

I set up the lid with a 30 gal. can, but it seems unnecessarily big (I have a very small shop). I'm leaning towards returning the Woodcraft lid and making a Thien box.

But do I need that 30 gal. size for efficient chip separation on 4" hose? Thien makes a good case that a baffle is the key design element, so perhaps can size could be smaller?

I would think a small can/box might result in less CFM loss, too.
Or is all this nitpicking, and I should just go with 30 gal?
Thanks for any thoughts.

[Neil Brooks]

They also sell one that's sized for a 5gal bucket. If you need the space, maybe that would solve your issue.

[Kevin Begos]

Thanks, saw the 5 Gal., but that's for 2.5 hose.
I have a 4" dc system and don't want to reduce and lose cfm.

[John Gregory]

If you use a smaller bucket it will fill up faster and reduce the material collected in the bucket. I have the same set up and I find that if I empty the 30 gallon can when 40-50% full, I have to empty my dust collector less frequently.

[Kevin Begos]

Thanks, John. Good point.
Sawdust does build up awfully quickly....
Will just stick with the 30 Gal.

[Bruce Wrenn]

While a 30 gallon can does fill fast, remember that when the Thien baffle is located inside the can, you lose 1/3 of your can's capacity. That is why I built mine as a "Top Hat," so as to not lose can capacity.

[Jim Sebring]

A planer or jointer will fill that 30 gallon can half full in no time. If I go beyond half full, the dust collector starts sucking the big chips into its bag pretty quickly.

[Kevin Begos]

Thanks, all.
Feedback much appreciated. Sticking w/ 30 gal.

[Curt Harms]

I would go for the Thien baffle over the Woodcraft lid--and I did. I don't have engineering data but I know the lids don't work with 6" hoses. Every chip will go into the can, right back out of the can and into the DC, just too much air flow for the lid to work. The Thien baffle works fine with 6" ducting which indicates that the separation process is more efficient with the Thien baffle than with the lids. I just put my Thien baffle in the DC funnel for the space saving but a lot of people have made free standing setups and seem happy with them.