Hello. I'm trying to make a 5.3 long part on a sr-20 screw machine. The part has a .160 diameter 2.5 long. .There are two 7/16 diameter,one at the end of the .160 diameter and one at the end of the part and the middle is .215 diameter. The Stem is allowed a little bit of run out but the body has to run true within .001 to each other.. I'm getting about .0025-.0035 run out on datum A which is the two 7/16th diameters.
I'm not sure what to do here. The guide bushing is set right,no out of roundness at all. My cutting tool is a .004 nose radius and on center. Any help would be greatly appreciated. Thanks