Don't know if y'all are familiar with http://www.Instructables.com
They have tons of how-to's for most anything.
I recently uploaded how I made a downdraft sanding table. I used our SLOMakerspace Vcarve and CNC for the tricky bits like the top and the funnel (concentrator?)
Here's the link if you want to take a look. http://www.instructables.com/id/Down-Dr ... the-Cheap/
I'll try to upload an image if I can figure it out.