Hi Group, Recently acquired an import D1-4 5C Collet chuck for my 12x36 lathe and am experiencing massive runout and wobbling to unacceptable levels (about 12 mils!). I am wondering if there is any adjustment that you can think of or whether I am wasting my time with this guy here. The eBay seller told me that how deep I screw the D Lock cams will determine runout. I tried dozens of combinations and with all of them I got basically the same 9 to 12 mils worth of runout. Here is a picture of the screws that I have on the back: The intriguing thing is that if I measure runout at the base of the chuck, I get less than 1 mils worth of variation. The way this chuck is constructed is that there are two halves, so the base would be the first half. When I measure the second half, which is where the collet goes, then I see the variation of up to 12 mils. If I place a part on the collet, I get the same variation. Any idea on how this can be brought to usable levels? Thanks!