This is one solution for dust collection on a Delta 10" Unisaw. This funnel is my design and creation as a solution for my 1946 Delta Unisaw. It works very well for me, but there are other solutions out there.
The funnel is made to fit the inside of the Unisaw cabinet closely. The vertical seams on the inside of the cabinet prevent the funnel from touching the walls of the cabinet. This small gap can be closed by either make the funnel a little larger and cutting slots in the edges to accommodate the vertical cabinet seams, or by filling the gap with something such as foam.
So far, I haven't found the small gap to be a big enough issue to require solving. I had some carpet padding lying around, so I used thin strips of that to close the gap between the outer edge of the funnel and the inside wall of the cabinet. It only took a minute and prevents virtually all the sawdust from bypassing the funnel.
This funnel is designed to reduce down to 5" round, to which I connected a 5" elbow and continued out the lower wall of the cabinet. A minimum of two tabs should be used on the perimeter of the round portion in order to help connect to the elbow. More tabs can be cut out if desired. I only drew two on the downloadable pattern.
This pattern is only half of two identical pieces. It was necessary to keep it two separate pieces in order to get it through the holes in the cabinet. Even still, it can be challenging to get the two halves into the bottom of the cabinet and connect them to each other along the seam(s) with small screws. After connecting everything, it is advisable to tape the seams and joints with a good foil tape.
I chose to also place a 1/2" metal screen covering the hole to catch a wrench or the blade nut in case (when) they were dropped. I removed the screen because it got clogged. I'm just careful not to drop anything when doing a blade change.
To use the pattern, print out, align and assemble with tape if printing on multiple sheets of paper (alternatively, you can have a print shop print it on one piece of paper). Lay the pattern onto a piece of sheet metal (I used 26 gauge) and transfer the relevant points (A,B,C... 1,2,3... & fastener drill positions on seam) using a punch. Remove the paper and draw connecting lines to match the pattern on the metal using a straight edge. Cut out the pattern. Bend each dashed line approximately 13 degrees with a metal bending brake (I made my own with angle iron, a two-by-four, and some old door hinges). Drill the holes for fasteners along the seam(s).
After both identical halves of the pattern are bent and drilled, put them together and figure out how you're going to fit the elbow and exit the cabinet. When you've got that all figured out, it's time to get on the floor, contort your body, and assemble it all inside the cabinet. [UPDATE] I've been using this for 3 years now and really like it. I never have to clean out the cabinet. It works very well.
Download printable PDF of pattern:
Click following link to download pattern:
PDF of Delta Unisaw Dust Collection Funnel Pattern
Photos
 Pattern transferred to sheet metal |
 Sheet metal cut out |
 Sheet metal funnel halves fit together |
 Elbow test fit to funnel |
 Elbow and exit duct installed |
 Funnel installed |
Funnel installed