I used 1/4" thick underlayment plywood for the dice tray, but you can use whatever you like, including MDF.
Just 1 piece 8″ × 12″ will do the trick for all the tray components. Simply cut out the parts and glue together. Optionally, you can add some felt to the bottom of the tray and of course you can finish the tray any way you like. Note: I didn’t glue the felt into place – I just let it lay there and stays in place just fine.
The YouTube video I added covers the whole build of both tray and dice tower and is less than 6 minutes long. The free plans for conventional tools can be downloaded in pdf format from my web site (link given in the YouTube video description below the video).
The dice tower was made using two pieces of 2×4 construction lumber that actually measures 1-1/2″ × 3-1/2" in cross section. Each length was 9" long. I started by ripping the rounded edges off each side, yielding a final width of 3" on each piece.
Each piece was individually loaded into the X-Carve and the inner run for the dice was carved out using a 3/8" straight router bit for he roughing pass, and a 1/8" straight bit for the finish pass. The second piece had the same shape but reversed horizontally so it mirrored the other piece when they were put together.
I painted the inside edges of the dice path on each tower half because it’s easier to do it before you glue the two together.
I then glued then together with wood glue and clamps, cleaning and sanding the surfaces afterwards. I finally finished the tower with a spray paint job.
That’s all there is to it.