Look at a "standard" center rail punching setup. As you cycle the key through it's normal (not exaggerated) range of motion, you'll see the fulcrum point shift from the rear of the punching to the center to the front, through a range of about 10mm. Thicker punchings are more compressible, and the effective fulcrum points moves through a narrower range. The key, meanwhile moves visibly down, then up the pin during the stroke. In an accelerated action, the fulcrum point looks to me to be moving no more than about a millimeter or so on the half round. Making the hole off center wouldn't change that a bit, but would increase movement of the key balance hole up and down the pin. The key ratio in an accelerated action remains more constant through the range of key travel than that in a standard setup so, if anything, the half round fulcrum decelerates the system. Ron N
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