Keeping the pieces together and properly oriented is vitally important if we are to acheive a "perimeter wrap" sometimes called a "box-makers wrap" which results in the grain pattern of the wood flowing around the tray in an uninterrupted pattern. By using one very long strip to cut the rail pieces we can acheive three perfectly matched corners, but to get all four matched requires this box makers secret. To explain that, I'm going to try a video...
So I spend some time tagging the rails with pieces of masking tape on the outside faces of each set identifying which pieces will the the front rail, right rail, back rail and left rail.
The final step will be to mill the groove on the inside face of the rails into which the panel will fit. That is done with a dado head on the table saw.
I set up the table saw with a stacked dado head, I test the cut width and cut depth on some scrap wood and tune it in to perfection. When it's ready I bring my tagged rails over and stack them all so the outside faces are up and teh bottoms of teh rails are on my right - which will be against the fence when I make the cuts. By having them all properly positioned before I start milling them, I have less to fool with and can pay more attention to making he cuts properly.
I have a narrow push stick to feed the rail into the blade, a fixed feather board to keep the rail tight against the fence, and a hand held feather board to keep the rail held down tightly against the table saw top, insuring that the groove I cut will be a consistent depth.
The final step is to set up the router table with a small radius dound-over bit so I can round off the inside top edge of these rails stock. Why just the inside-top edge? Why now? Why not wait until later or do all the edges now? Because the rail height above the panel - once it is installed will not be tall enough to run a router bit on teh inside edge without allowing the top of the router bit (that cap screw that holds the bearing in place) to damage the panel itself, so this edge must be done before assembly. Doing the outside edges after the tray is assembled will make nicer looking corners: no misalignments.
I run all the strips through, using feather boards to insure a consistant cut, and when I'm done, I have enough rail stock made up and shaped to make 10 tray tables. I only need enough to make 8, but I like to have some extra just in case I mess up. If I mis-cut a piece, and have no fall-back plan, I'd have to start from scratch amd mill out and shape another set of rail stock. If I make no mistakes, I'll tuck the extra away and use it another time.
And that's going to do it for this session. See you next time.