I’ve been planing to build a down-draft table for quite awhile. It’s probably as important as a dust collector for staying ahead of dust collection. Someone gave me a furnace blower that puts out a lot of air, and I’ve been planning and plotting. My big hangup has been that the filters will plug up fast and I’ll be cleaning them all the time.
This weekend I cut up a bunch of MDF and was surprised to see quite a pile of MDF dust in my dust seperator. When the air and dust enter the seperator, the velocity drops allowing the heavier dust particles to fall from the air stream. Having seen MDF dust hang in the air in the shop, I would never have thought it would drop out in the seperator, but it did! And it got me to thinking … what if the downdraft table could capture some or most the dust in a bin instead of sucking all of it into the filters? Great idea, but then I’ll just have a bin full of dust instead of filters full of dust. How to get the dust out of the bin? Make a drawer? Hinge the top of the table and clear it out with the dust collector? What about just hooking the dust collector to the bin?
I’m thinking right under the blower could be a port for the dust collector. The dust collector could run while the blower was running, or it could be just be turned on now and then to clear the bin. In the drawings, the green thing is a filter. I’m thinking perferated hardboard for the top (not shown). The slats are on an angle to avoid blocking the holes in the hardboard, but may have the secondary effect of directing the airflow. I’m wondering if there should be an additional baffle in front of the filters so that air is only taken from the top of the bin instead of the whole side.
Any thoughts? I’d appreciate suggestions and feedback and will post design and construction progress.