Ironworker Prototype II Geometry
See the OSE Ironworker Prototype II for other details. Prototype II has the following geometries:
- The cylinder has a 5" bore, 16" stroke, 2.5" shaft thickness
- The upper shear blade is in line with the line from the main pivot
- The end of the upper shear blade closest to the main pivot is 19" away from the main pivot
- The blade is approximately 14.5" long
- At full open shear position, the end of the blade closest to the pivot is open 1.5" wide, and the end farther away from the pivot is open 3" wide
- In the fully closed shear position, the upper blade edge closer to the pivot is about 1/4" below the edge of the lower blade, while the far end is just closed
- In the 1" open position of the blades closer to the pivot, the farther end of the blades from the pivot is 1.5" open
- When just closed at the position closest to the pivot, the end of the blades farther from the pivot is 5/16" open
- Conclusions: the far end of the blade from the pivot travels a total of 3" vertical motion; the close end of the blade travels 1-5/8" vertically
- End point of shear blades closest to the pivot has a mechanical advantage of (cylinder travel/ blade travel) = 16/1.6 ~ 10
- End point of shear blades farthest from pivot has a mechanical advantage of 16/3 ~ 5.3
- To obtain 10x mechanical advantage with a simple lever design ironworker machine - if we use a 5" cylinder - then we need to use a cylinder with a stroke of 12 inches to travel 1.2 inches. An 8" cylinder gets us a ~7x mechanical advantage.
Conclusions: we can likely shear 10" slabs with the 7x mechanical advantage - 140 tons at the beginning of cut. Need to figure out mechanical advantage at end of cut based on geometry of having a 1" opening at the end closer to the pivot. We want to have the farther end of blades be about .5" higher than the closer end of blades (accprding to point 7 above). Thus, whatever location of blades we choose, we need to have far end .5" above the close end of the blades.