Encoder Products Company designed and implemented the first flexible tether mount for rotary encoders several decades ago. The tether serves two purposes. First, it keeps a hollow bore or thru-bore encoder from rotating with the shaft on which it’s mounted. Second, it allows the encoder to accommodate shaft end play and run out without transmitting those loads to the encoder bearings. EPC anti-rotation tether mounts are engineered to achieve a perfect balance of flexibility and stiffness. For best encoder performance and longevity, we recommend using only EPC flex mounts on all Accu-Coder™ encoders.