Transverse pen press

We designed, fabricated and supplied a machine for pushing pens into detachable tow bars. There are even so many different thicknesses in tow bars as there are in pens therefor, is there a big chance of incorrect assembly. We have therefor chosen for a vision system with a camera which takes images of the ball and the pen before they are compressed together. Belong the ball and pen together than they are pressed together, if not than their will folow a alarm of rejection.