A metal bending press brake I built for the shop press using tractor Cat 2 top link pins as guide pins. Spring is a high tensile fence tensioner spring cut in half (half for each side). The die is removable, aligned to the table with index pins.
Examples of bent flat bar and sheet metal using press brake:
Tweak - replaced guide pin top washers with set collars to raise press brake punch higher above die when resting to ease removal of workpiece after bending: