ABSTRACT
To illustrate the guided design process, suppose we wish to design a helical compression spring, having squared and ground ends (total number of turns = active turns + 2), to fit in a 50 mm diameter hole and to fit over a 25 mm diameter rod. The spring is to exert a force of 90 N when it is 87.5 mm long and a force of 630 N when it is 50 mm long. Loading is essentially static. Clash allowance should be >10%. The spring is to be made of music wire (ASTM A228) and is to be "set" after winding. A preferred wire diameter is to be used (Table 22.1) and the number of turns should be specified in half-tum increments.
