The part I'm cutting is basically a square. The material is 1/4" thick 3003 Aluminum and I'm using a 1/4" two flute end mill at 3050 RPM and 13 IPM. The program is coded to do conventional milling on the roughing cut, which starts in the upper right corner and works counter clockwise, cutting the outside of the blank away. Then the finishing pass is .005" on all edges with climb milling starting in the lower left corner and working clockwise. the problem is that on the finishing cut it's only removing material from 3 of the 4 sides. What could cause this problem? I've banged my head for over a week on it and have considered back lash, movement in the table, movement in the work piece, movement in the cutting tool, but nothing makes sense. The problem is repeatable and to get the 4th side correct I have to take .03" so it's off quite a lot. Any ideas?