This thread is for me to discuss and receive feedback on my ideas to rebuild my RAS table and make a rip sled for it. While initially writing this post, I am feeling like heading back out to the shop, so will edit the thread later.
The RAS is a Delta 33-890 as pictured in my shop here and here.
Underneath the melamine are two sections of laminated MDF (total thickness of MDF = 1 1/2"). By laminated, I mean bolted together with 1/4-20 hardware. Not glued. Including the laminated MDF section behind the fence, this makes three sections. I want to return to a three section table - with the turret style design of my RAS, if I move my fence to be between the frontmost and middle sections I gain the capability of miters to about 80 degrees. Not something I need to do everyday, but just often enough that I would like to be able to easily make the switch. This would also have been helpful during the horizontal blade operation depicted in the second picture (above).
The frontmost MDF section is bolted to the RAS stand frame and the other two sections are pulled forward by 1/4"-20 threaded rod (the bottom of the MDF has a 1/4" dado for the threaded rod). These are the two knobs on either side of the blade height handle. The top melamine (currently one piece) is then bolted to the front MDF section using countersunk 1/4"-20 hardware.
My shop is small with very limited horizontal surfaces. I am also easily overcome by the rampages of the clutter monster. Sometimes stuff accumulates on the RAS table. While I will try to eliminate the occurrence of clutter, I also want to add some reinforcement to the table. To this end, I want to add some steel flat stock, 1/8" thick (maybe 1/4" thick - we'll see what Mr. Wallet says when I price flat stock) between each of the sections. This will be two pieces of flat stock. The installation of the flat stock will also serve to lock the MDF sections together, helping to force a perfectly flat table top without unevenness between the front and middle sections when the fence is between the rearmost and middle sections (as it is in both pictures, above). I want to have a minimum of 1" width of steel inside each MDF section regardless where the fence is. Applying some algebra (this is a good word problem for kids) indicated that I want to use 3.5" wide flat stock with 1.75" slots in the MDF since I typically use a 3/4" fence. This likely means that I will need 4" wide flat stock with 2" slots depending on market availability of flat stock widths.
My idea for this is to start with a quarter sheet of melamine. Make a reference trim with the EZ Smart and then rout two 1/4" deep by 3/4" wide dadoes relative to this reference cut. One will be on the bottom of the sled maybe a third from the rear - this will be the guide slot - I'll make a short fence for use with the sled. The second dado will then be on the top very close to the rear for the installation of a fence on the sled to support the workpiece. I might well also make 2 - 4 T - slots from front to back for use as sliding clamp holders. I could then tap a couple 1/4"-20 holes near the front of the sled and scavenge the handles from my angle grinders to keep my hands well away from the blade.
If I do decide to use T-slots, maybe I should laminate a couple quarter sheets of melamine together, or even one melamine for the bottom and MDF on top.