Then, while building the table, I found it was a little hard to adjust without some diagonal bracing to hold it in place while attaching the top crossmembers. I added the diagonal braces you can see in the photo, made of 1/2″ x 1/2″ x 0.062″ square tubing, pounded flat at the ends, drilled, and bolted to the tops of the leg assemblies with 1/4-20 bolts. This way I could adjust the table for squareness and it wouldn’t change when I tightened the top crossmember attachment bolts.