Level and crown first
Tennsmith states that the brake will not bend properly if it is not level.
Its base is set slightly crowned in the center, and checked so an equal amount of light shows at either end.
Six steps in order: level the brake and check the crown, set the clearance (2 t within four gauges of capacity, 1.5 t if lighter), set the clamping pressure, make a test bend, bend the piece, and verify the angles at both ends and the center.
- 1
- Level the brake; equal light at both ends shows the crown is right
- 2
- Set the clearance from the metal's thickness
- 3
- Set the clamping pressure at the ends, then match the center
- 4
- Test bend in scrap and adjust
- 5
- Bend line at the front edge of the fingers; overbend if springback requires it
- 6
- Check the angle at both ends and the center against the drawing
Sources
- HBU48-12 and HBU72-16 floor model box and pan brake - operating manual - Tennsmith Inc. (copy hosted by Conklin Metal Industries)
