Question about an alternative configuration: Harbor Freight DC

[marks1]

Please forgive if this is answered somewhere else; I searched to no avail, both on and off this forum, and am kind of surprised the following question seems not to have been discussed.

I have a Harbor Freight DC and long ago abandoned the bag filter filter for a Wynn cartridge. Is there is a good reason the Thien baffle cannot be built and attached underneath the ring that comes with this DC? I understand this puts the baffle and the chip collection container, in this case just the usual plastic bag, on the exhaust side of the blower and makes the impeller subject to "chunks", but aside from that I see no reason not to put it there. Am I missing something fundamental? In my case, the DC serves only a table saw, and occasionally, a jointer. A separate air cleaner runs for airborne dust.

Thanks...

[bbain]

Yes, you could do this.  baffle on the bottom of the ring, seal the top except for the exhaust stack/tube and it will work.  you could ditch the bag for a rigid garbage can if you integrate the baffle into a bottom plate on the ring that has a circular dado to fit the top edge of the garbage can.  It is just nicer to have the blower after the separator so you don't get the chunks banging around the impeller if you happen to suck one up, but the separator will work in both "push" and "pull" scenarios.

[Holsterguy]

Sorry so late with this, but check out April Wilkerson on utube. She pretty much does this exact thing with her hf collector.

[ProfessorGT]

marks1,

I did exactly what you stated, about 10 years ago with my HF 2hp DC (added a Thien baffle and a Wynn Pleated filter in place of the filter bag). I have no problems with it at all, other than in hindsight, I would have, (and plan to do so in the future), reconfigured my system to add a "TopHat" Thien Chamber on top of a garbage can (either a plastic Brute or a 32 gallon galvanized garbage pail), to the inlet side of the dust collector, in effect making it a 2-stage system.

As you can see online many have done this already with great results. With the Thien baffle under the original HF mid-section, it still is a single-stage process, albeit improved from the standpoint of better separation, so less filter loading.

The reason I responded is because the most compelling reason, IMHO, for going to a 2-stage system, aside from less frequent filter loading is this: I have had small pen pieces, sanding pads, etc., get sucked up into the vac. Unfortunately, they fall prey to the impeller, and typically the impeller wins!

So, by going to a 2-Stage system, anything that mistakenly gets sucked up into the system will hopefully find it's way into the bottom of the waste collection barrel, and thereby be easily retrievable, without being damaged! Something to consider if you work on a lathe with small items like pens. The other benefit, as you mentioned is less chance if damaging the impeller itself.

I mention the TopHat style, as opposed to one that hangs inside the barrel, because it makes emptying out the waste easier, and allows filling the waste pail more (when the baffle is inside, versus on top of the pail you lose waste space, so that equates to the need for more frequent emptying). One design I saw, had a simple connection with two pieces of plywood at the top (outlet) of the TopHat screwed together with four handwheels (bolts with attached wooden knobs). Remove the handwheels the the barrel slides right out, as the flexible hose connection from this top piece of plywood to the blower motor allows enough room to slide the pail out with the TopHat in place. Yes, you then need to remove the TopHat from the pail and set it aside to empty the pail, but it's simple and effective.

Additionally, I've seen other designs where the TopHat is hard mounted to the frame just like the blower motor, but in these cases some sort of mechanism to lower the pail for disconnection is required. I may go that route, but it's a bit more challenging to make some sort of a pail lift. I've seen some use wooden wedges under a bottom plate that the pail sits on, but I don't care for that method. Maybe a plate with a hinge at the back that would allow it to swing down, but that may not allow a properly sealed pail to drop away properly. Ah yes, the options are almost endless!

Don't mean to ramble, but you get the idea.

Enjoy, and good luck with your design, ........ if you haven't already got it done!

GT