to follow up on by baffle install:
I installed a baffle in a Harbor Freight DC unit that uses a Wynn 0.5 micron filter. I installed the baffle made from 3/4 MDF in the center section of the HF below the funnel and the intake. I ran a threaded rod up from the baffles center to hold the Wynn Filter in place with a threaded knob.
Without Baffle.
Before the baffle, in a short time the filter would be clogged and I would clean by thumping and blowing air out to in. The clogging was significant as all the pleats inside the filter were packed with dust and shavings. I would have to repeat this often to get acceptable draw and when the bag got over 1/2 full it would clog in just a few minutes. I guess the cyclone was actually blowing the bag discard back up into the filter. When I change the bag out I also clean the filter thoroughly with compressed and shop vac. I will get at least 1 gal of dust/debris out of the filter pleats.
WIth the Baffle.
I used the DC with the baffle for a few weeks now. DO all sorts of tasks from planning to sanding. The bag is about 1/4 full. During this entire time, I never felt that the DC had diminished much at all without ever cleaning the filter. I removed the filter today and inspected it. The pleats were remakably clean with 0 evidence of shavings.....just fine just. I used a shop vac and blew compressed air outside in to thoroughly clean the filter. When done there was about 1/4" of find dust in the shopvac. Also I noticed most of the dust was capture near the bottom of the filter suggesting the baffle is doing its thing.
Its not scientific, but the baffle seems to work exceptionally well as the DC continued to provide excellent draw, similar to what I remember with a brand new filter, and even after several seeks of use and without cleaning the filter.