Hello there, I'm working on a design project where I have come upon a mechanical problem that I'm having trouble with. Basically I'm making a kind of specialized stapler (at least I think that's a good translation...), and I want it to clamp the staplers using a mass accelerated by a spring, that strikes a surface on the tool that does the stapling. I've set the staples up in a machine that pushes on them with constant speed, and recorded the reaction force from the staples as they are pushed together. It's basically a rather steep curve that peaks at 400 N, over a distance of about 20 mm and a time of 0.67 seconds (with a constant speed of 30 mm/s). The background is that I'm trying to decide if I want to go with just a rack and pinion and an electric motor that generates a force of 0,4 kN, or if I should go with having a motor compress a spring that powers a hammer. It doesn't matter much if the compression is slow, but the clamping should happen pretty quickly after the button is pushed, so if I go with the rack and pinion, I have to get a pretty expensive motor to do the pushing. If the motor is permitted to work slower, while compressing the spring and preparing for the next cycle, I might save a bunch of money. All of this is, however, depending on what kind of spring and mass I should go with, and right now I'm completely clueless. So please, how do I go from knowing the force as a function of time and/or distance to knowing what spring/mass I need to smacking those staples together? Help would be greatly appreciated!