About 2 years ago, I needed another shelving unit in my work shop. I made one, and made it about the same size as a steel shelving unit I already had. At that time, I did not document the design or how I built it, except for my Google Sketch-up design.
I just finished a project at my Son's house, which was finishing his basement. We bought a sheet of 1/2" MDF to cover the pool table during construction. After construction was done, he had no use for the sheet. I decided to make another shelving unit and consume the sheet, versus throwing it away. For another $32, I bought (8) 1x4x8's to make the shelf. I already has (4) 2x4x8's in stock for the legs.
Note that one of the shelves must be made of 2 pieces. I placed a spacer underneath and glued up the 2 pieces. They are shown above as the 8-3/4 wide piece, plus the piece in the upper LH corner.
I sawed the 4 legs to their 72 inch length. I then used a big square to transfer the shelf heights to all 4 legs. I will later use these marks to position each shelf when I install them to the legs.
Cutting the grooves in the shelf sides
There are several alternatives to which process to use to cut the 3/8" by 1/2" deep grooves in the shelf sides...that hold the 1/2" thick MDF shelves. One can use a router table, but it will take several passes because you can only route about 1/4" deep max per pass.
Another option is to set up the table saw to remove the 3/8x1/2 rectangle on 2 pieces. This takes a lot of trial and error set-up on the table saw.
I chose to use the dado blade option. It takes trial and error to set up the table saw fence and blade height, but you can run all the boards through in just one pass.
A while back I bought 2 clamps from Rockler that allow you to clamp a scrap piece of wood to the fence. You sacrifice the scrap wood piece versus running the dado blades into the metal fence.
I used my Harbor Freight dado kit for this project...........
I made a nice pile of wood chips on the table-saw doing the dado operation !!
I used my Kreig fixture to pocket screw the shelves together..........
The special Kreig clamp plyers are really handy for holding the corner in the right position while you install the 1st screw:
Finished shelf frames
Counter-sink Drilling on Shelf sides
I drilled the side boards before assembling them, so I could screw the sides to the 2x4's with #8 by 1-1/4" wood screws...
I assembled the top and bottom frames to the 2x4's, on the ground. Then I set it up vertically to install the rest of the shelf frames..........
Finished Framed Unit
Finished 6-Shelf Unit
If you are building this shelf unit, select your 2x4's so they are straight and not twisted. I chose to use up 4 boards in my inventory, and they were either twisted to start with, or twisted over time. I had to use some bar clamps to straighten them as I assembled the unit.
This is a relatively low cost and quick to make shelf unit. It is sturdy enough to support heavy tools.