Downdraft Table

The following posting is a project I started midstream of building an entertainment center for my basement.  While assembling the entertainment and cleaning the shop I was reminded of how the dust just seems to find its way to every part of the shop.  I then turned to the internet for a few ideas .... and quickly came to conclusion that converting my existing hard maple table saw outfeed table into a multipurpose work station would be ideal.  I quickly disappeared to the Home Depot for a few supplies and began crafting this project based off of a few pictures I saw on the internet.  I must credit the idea for this project from http://www.fineboxes.com/DowndraftTable.htm.  The outfeed table has now been converted into a fully functional downdraft table, outfeed table and storage cabinet.  The base of this cabinet consists of 1/2" plywood construction and 2"x2"s with Hard Maple for top.

If you want to attempt this project here is a list of supplies:

(3) 1/2" X 4' X 8' plywood

(9) 2" X 4" X 8'

(1) 60min timer switch

(1) 120VAC outlet

(10) Power cord 10-2AWG

(2) Box of Screws

(1) Door gasket / weather stripping (to seal the removable fan side)

(4) 20" X 20" furnace filters

(2) 1" X 1" steel angle iron to improve surface rigidity

(6) 1.25" Pan Head screws

(1) Hard Wood Top (Size to vary based on your shop)

(1) Old Furnace fan or blower

The finished dimensions for the base of my downdraft table are 39" X 43".  The height of my downdraft table was customized to match the height of my table saw and thickness of the hard maple top.  Since the downdraft table in my shop is a permanent fixture I finished the base with a hardwood trim to ensure it remains level with the floor and table saw. 


Base Construction

The shell of the downdraft table went together very quickly. I used several 2"x4"s to frame a simple pallet for the plywood base and sides to attach. The sides were then secured with 2"x2"s up the corners. A 16"x16" opening was created for the furnace fan exhaust. This opening will vary depending on the size of your fan. For maintenance of the fan / motor no glue or silicon were used to secure the fan side of the cabinet. I instead installed a strip of weather stripping around the perimeter of the side and utilized screws to compress the seal. This seal will help to ensure that no extra dust can enter the main vacuum cavity. 

The Top

The top is a grid of 5/8" holes spaced 1.5 in. center to center.  I selected a smaller hole given the size of my table and desired to prevent loosing lots of small parts into the bottom of the table.  With over 600 holes the table has had plenty of air flow.  I must say that drilling holes in hard maple took over 5hrs with a forest bit and by the time I was done I never thought I would be able to stand up again.  A small jig made from a scrap piece of plywood allowed me to make aligning the holes a breeze.  With the overall dimensions of the top and hole area being greater than 3'x3' I have had now issues with air flow.  I also reinforced the top with 1"x1" angle iron between the holes drilled on the top side.   I have also allowed for the top to be secured to the base with pocket screws that should allow for quick removal as needed.

Filter Frame

With the furnace fan installed into the plywood base and 2x4's I began assembly of the filter frame.  The filter frame is made to retain 2 sets of (2) 1"x20"x20" furnace filters. The frame was built to enable removal of the filter frame for easy cleaning and or replacement.  2x2's were used to guide the filter frame into place.  

Filter Frame Removal

After review the cabinet and need for filter maintenance a hole was cut into the side of the base cabinet to allow for easy filter frame removal similar that of a home furnace.  This simple modification to the design will allow for very quick maintenance and inspection of the filters.  I also cut a 4" hole near the bottom of the base for a 4" dust collection blast gate.  This will allow for removal of large debris and or dust removal that would have accumulated in the base of the cabinet.

Storage
To further utilize the space of this cabinet I cut into the main cabinet to create a small shelf for sanders, sandpaper, etc.  This shelf space is all sealed with silicon from the inside to prevent any air leaks from detracting from the airflow through the top of the cabinet.  You will also not the installation of the 60 min timer and outlet on the far upper right of the base cabinet.

Complete Slide Show.