Since I know I need that kind of space, it was time to find something more useful as an actual workbench. While browsing reddit.com, a user called kurtz61 did his version and pointed me at the instructions on One Project Closer.
I decided on a few modifications before I went to the big box store. First I am not doing the reinforcing steel bar, instead I went with a torsion box for the top. Second, I shorted the bench to six foot from eight foot. This fits my garage a little better and gives me some correctly sized plywood to build a rolling cart or two for smaller tools such as my table saw or router table. Third, I used 2" casters. Total load is over 400 lbs and that should be plenty for this bench.
Off to the Big Box. I picked up a sheet of 3/4" AC sanded plywood, a sheet of 3/8" AC sanded plywood, seven 2x4s, eight Simpson ridge tie connectors, a box of 1 1/4" wood screws, four 2" casters, and a tube of construction adhesive.
While there, I had them rip the two sheets of plywood to 2' width. They will do one cut for free and will do a much better job than I can do with a circular saw.
I followed the cut list for the 2x4s from One Project Closer - except that I made the overall length six foot. I then cut off 24" from my 3/4 plywood sheets and one of the 3/8" sheets.
Here is all of the 2x4s dimensioned.
Next up was to build the top frame. I used the Simpson ridge ties with a scrap 2x4 as a leg to layout the stretchers and end cap pieces.
I then installed the legs and a middle stretcher for additional support.
Next up was the bottom of the torsion box. I used my jig saw and notched the corners of a piece of 3/8" plywood. Then using construction adhesive and screws, I attached it to the underside of the top.
This is what it looks like flipped back upright.
Then I used more glue and screws, I attached the 3/4" plywood top. I made sure to just countersink the screw heads so they will not snag on any projects I will work on.
I then used some scrap 2x4s to line up the structure for the bottom shelf and attached some more Simpson ties.
Once the shelf support was built, I added two caster supports. The casters won't attach well to the end grain of the legs, so this gives them something to solidly screw into.
Then I installed the four casters.
After I flipped the unit onto it's wheels it was time to fit the bottom shelf. I used 3/4" plywood and just like the base of the torsion box, I notched the corners. It was attached with more construction adhesive and screws.
The mobile work bench is complete! I jumped up on it as a test and it didn't move at all.
The left over plywood and 2x4s will be used to build a mobile table saw stand that lines up with this bench. I may also build a mobile router table stand for my router table project.