PCB VISE intended for mounting on a board (I used 3/4 melamime) to prevent sliding around on your bench. Ithis implementation uses 1/2" EMT and 1/4-20x1" screws for the vise. Attachment to the base is 1/4-20 x 3/4 screws ant countersunk teenuts. I added some posts for securing wires and added a mousepad on the bottom for friction. The jaws are 80mm to match 100mm boards and for larger boards adjust the arm and jaw lengths.

Freecad files are supplied with parameters in spreadsheets so you can adjust to your needs.