I work for a driveshaft manufacturer and we use Gauge R&R as a tool for approving all of our driveshaft gauges. The other day I was running an R&R on our new Jenoptik Opticline gauge. The shaft variant has a stub shaft on one end and a U-Joint yoke on the other. Our gauge engineer stated that we need to make sure and mark the shafts so that every operator puts the part in the exact same way. With this being a cylinder, I told him that radial position shouldnt matter because the shafts are pretty much symmetrical and we are measuring length and 2 runouts. I told him that if you mark the shafts to ensure every operator is putting the shaft in the exact same way, are you really getting a true R&R or are you just checking to see if the gauge will repeat?