I purchased a P/C not to long ago and have used iti a couple times but I noticed that I have to barley touch the paint to allow for the pad to rotate. If I apply any pressure whatsoever the pad will not spin but continues to vibrate. I have found that my results are good but wasn't sure if this is normal behaviour (CDN spelling). Any insight to this would be helpful thanks. Is this some sort of safety feature? If this is normal, what is the idea behind it?