Since the majority of roll forming lines use a computer to control punch and shear operations, the majority are also using rotary encoders to measure length. If the computer control system is the brain of the machine, then the encoder is the eyes and ears of the brain. Everything the length control system knows about the material – distance, speed, direction of movement – comes from the encoder and the measuring wheel affixed to its shaft. It is for this reason that nearly all length variance problems are due to the encoder, the measuring wheel, and how they are tracking the material. The computer that controls the machine and its parameters are almost never the cause of length variance. Variance usually comes from the real world.
To understand how the encoder plays such a vital role in controlling length, it’s critical to understand how an encoder works. You must also understand some fundamentals about the geometry of the measuring wheel and how alignment and mechanical backlash (slop) affect consistency. This post will cover the fundamentals of encoder function.Continue reading “Encoder Basics”