I found a set of plans at http://www.shigshop.com/thickness-sander.html for a thickness sander, bought them, and embarked on the task of building this project.
It is a lot of fun -- and a reasonable amount of work. Since I am making this at Tech Shop, I have all of the space and tools necessary to make the job easy.
So far, I have the sanding drum and four conveyor supports done. It has taken me about 20 hours to get this far.
Step 1: Cut out the MDF disks
I made these on a CNC shopbot using vCarve Pro. The MDF is 3/4" thick.
Click here to see the ShoBot do it's stuff: http://youtu.be/Febtki81qE0
Step 2: Prepare blocks for use as rams for the glue-up process
I then cut 2" square blocks of pine and drilled 1 1/8 holes in them. I built a jig to allow me to quickly and safely drill the large holes. I used a forstner bit,
When I was done, I had about 35 blocks.
Step 3: Glue the MDF Disks to 1" Steel Shafts
I drilled a hole in a 4x4 and placed the shaft in the hole. I then placed the disks over the rod and used a 10 Ton arbor press to force the MDF disks down the shaft.
I used Original Titebond PVA glue and liberally applied glue to the disks. I then used the wooden squares and the arbor press to ram the disks together on the steel shaft.
This took a while , but I was able to apply pressure. Note the glue squeeze-out.
I used long clamps to apply pressure while the glue dried.