2-stage DC, smaller "fines" bag?

[Eddie Ziegler]

I, like many others, have added a 2nd stage to my 2HP HF dust collector by way of the 30gal can/Thien baffle combo. I'd like to put the can on the cart that came with the DC to retain the system's mobility; most conversions I've seen out there end up putting the can where the motor mounts, then building some additional support to mount the motor above the can.

Since I get so little material actually making it to the large plastic bag that came with the DC, I'm wondering if I could instead put the can there and just make the "fines" bag smaller? Is there some physics involved that I don't understand which makes this impractical? I may need to upload a clarifying sketch.

Thanks

[glenn bradley]

If your separation is good enough the last bag can certainly be reduced. The Dust Deputy on my shop vac catches so much of the spoil I got rid of the vac's barrel and built the motor/filter into a small box; maybe .5 cubic foot of space for spoil that gets past the DD. I get about a tablespoon of talc sized dust in there every 10 buckets of spoil or so.

[Andy Giddings]

Eddie, if you look at some of the bigger cyclone systems from Oneida and such, there is no dust bag as such - just a clean out box underneath the filter. Agree with Glenn, there's no reason not to replace the large bag with something smaller - as long as you never over fill of course.
I think a lot of people retain the bag under the filter as its fairly easy to build it that way instead of a separate container.