Programmable servo-motor quality controlled continuous multiple coil spring forming method and apparatus

A spring forming machine is provided with closed-loop feedback from sensors which monitor dimensions of the coils and heads of the spring being formed, servo motors which control wire feed speed, coil radius and pitch forming elements, and coiling direction. Video cameras form pictorial images of the spring being formed. The images are digitized and fed to a central computer, along with images from similar machines forming similar springs, which compares the signals, such as photometric images, from the different machines, which represent actual spring dimensions, with a single stored image relating to the desired dimensions, such as head shape, coil diameter, and the positions and angles of bends. Discrepancies are correlated with causation data, such as feed roll slippage or material hardness variations, and adjustment signals are sent to the machines. Machines producing errors are interrogated more frequently by the computer. Large errors or failures to respond to adjustments triggers an alarm.