15-21 Grippers Rise Unevenly

The main problem is most likely gunk where the gripper stems move up and down. Without looking at some prints that are upstairs in the Vandercook files, I believe these are the same as the Vandercook #4 grippers that pass through a sleeve that is held in place with a set screw in the gripper bar. If the “taken apart” didn’t include the disassembly of the grippers themselves, then this may be where the problem is. And people like to crank down on the set screws and set too hard, the screw can deform the gripper sleeve. Lubricate gripper stems only with powdered or flake graphite. If the sleeve is deformed, that will bind the gripper stem, and replacement of the sleeve with a new one may solve the problem.

Fritz

Thanks for your help Fritz. Without (hopefully) murdering the terminology, here’s what I found.

When I removed the gripper assembly, had someone hold it stable and pushed on the lower bar, all the grippers were raised to the height they should be which indicated that the difficulty lie somewhere between the assembly and the pedal. Upon further examination I found the nut on the small vertical bolt that is on the opposite side of the handle was missing and not stable and that the springs and collars inside the cabinet which need to be tightened and exert some tension were loose as well. Once all that was remedied as best it could be, things worked much better. They still need the correct nut for that bolt and perhaps a new spring assembly but at least it is useable right now for class. Thanks once again. Neil