At home during a holiday, I found myself in need of a clamp larger than what I already had. With most stores closed I decided to make my own based of the Bessey clamp design. Total cost was $0 using scraps of metal I had laying around. compared to store bought ones which easily run for $50.
1x nut (mine is 2" long)
1x bolt that fits the nut
1x 20" of 1/4" thick x 1" flat bar
1x 5" of 1/4" thick x 1.5" flat bar
1x 6" of 1/4" thick x 1.5" flat bar
1x 2" round bar
first step is to weld the end of the 20" long 1" flat bar onto the center line of the 1.5", 5" long flat bar.
Obviously your going to want everything as close to 90 degrees and parallel as possible so everything lines up nicely when complete.
On the end of the 1.5" bar I welded a washer for a nice clamping surface.