Forces, Friction, and Torque (Oh My)
In this chapter we’ll look at static (unmoving) forces and figure out what torque and friction really mean. Why study statics in a book about things that move? 1) A static problem (one that is balanced and unmoving) can be a snapshot of a dynamic (moving) problem, and 2) most of the time we can isolate a statics problem that represents the worst case of a dynamic one (i.e. when the weight is farthest from the motor shaft and hardest to turn). I’ll cover essential tools to predict forces and torques, go over vocabulary and define units (what the heck is a gram-centimeter?) that will help you choose components. Time will be spent describing what friction is, then describing ways to get rid of it. From WD-40 to proper clearances, this is one of the handiest reference sections for DIY mechanism troubleshooting.