I have a Sears Craftsman hand-powered, reel-style lawn mower. The handle is shaped like a U. It connects to the lower U-shaped piece with four bolts (two on each side). The handle and lower parts are made out of metal tubes, about 1/2″ diameter and about 1/16″ wall thickness. Where the handle bolts to the bottom part, the handle is flattened. I bought this lawn mower two years ago to replace the hand operated reel mower that worked for 30 or 40 years. Unfortunately, parts were no longer available.
About six months after buying the new one, the handle sheared off at the top bolt. Sears replaced the lawnmower, but only after claiming my yard was larger than what the lawnmower was designed for. I tried to explain the replacement would also break because the design is faulty. The replacement mower lasted over a year. Yep, you guessed it, the handle sheared off at the top bolt. Still under warranty, so Sears will give me another faulty mower. The Sears design monkeys must not understand how to calculate mechanical stresses, especially in flattened tubes that have bolt holes drilled in them.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.