“I’m using a small diameter split drill bushing and I can’t seem to get the drill parallel to the centerline of the spindle. Why?"

• A common cause for this problem is locking the second set screw on the bushing. The holes for small diameter drills do not extend
  the full length of the bushing. The back end of the bushing usually has a large internal chamfer or a counterbore. This cleared area is under the second lock screw. When you tighten this screw, the bushing may distort, shifting the drill’s position. There may be line contact on which the drill will pivot. The solution is to use the front locking screw only.
• A second cause is that the bushing is too short. The first set screw is locking on the back of the bushing, causing it to collapse instead of gripping the shank of the tool.