I tried to like this center. I really did. It's big, it feels substantial, and it's exactly what I'm looking for. The first one felt like it had positive stops every quater of a turn. I figure in any production line there will be duds, so I had Amazon send me another one (thank goodness for Amazon's easy return system). The second one is better, but I can still feel the bearings grind when I turn it. Hooked up to the lathe, at slow speeds, it feels and sounds like a pepper mill grinding pepper- not the smooth, quiet live center I was expecting. Still hopefull, I called PSI directly, figuring they would find me a good one and send it to me, I don't doubt all the other reviewer have good ones, I'm just seeing some poor QC up the chain. Anyway, I could hear the technician's superviser talking to him in the background, and he basically said that's how it's supposed to run. Maybe it will get better with time, he tells me. He said if I wanted a quiet, smoother center I should look into their more expensive package (~$80). I was pretty surprised since they advertise it as a "smooth running" center.