My husband is building me a sewing table and I have a structural integrity question. The table base consists of four purchased (Home Depot) metal brackets. Each bracket has three slots for one vertical and two horizontal 2"x2"s. The table base measures 22 1/2" x 64" and the legs are 24" long. The table top consists of 3/4" thick particle board sandwiched between layers of melamine and measures 36"x78". In addition to the weight of the table top, the table base needs to support three sewing/serger machines (approx. 30 lbs. each) plus drapery fabric or quilts being sewn and other miscellaneous items. Should the center of the table have anymore supporting legs or are the four legs enough to support the weight without the table sagging or giving way?
If it doesn't bow, it should be fine. 2x2 is pretty stiff over a short run (5') like that. I have a tape cabinet that holds 120 VHS tapes and is topped with a 30x30x1 piece of marble that is supported by 4 2x2 legs.