That was tramming the node or the Y axis in the pic.If I understand your question correctly, I would only tram a vise in if I was sure I would not be moving the knee up and down. Tramming the head to a piece in the vice would in fact align the spindle with the piece, but if that piece were not perfectly in the same plane as the table top (perpendicular to the knee's vertical axis) then moving the knee up or down would throw things off since the spindle travel would not be perpendicular with the knee's vertical travel. The spindle would be at a slight angle to the knee's vertical travel.
Ted
That was tramming the node or the Y axis in the pic.
Hi Guys,
If you are going to tram the head, you really need to use the table surface, particularly if your mill is adjustable for nod as well as angle. Have you actually checked to see if the bed is truly flat and doesn't have any twist in it ? Once you have then you can tram the head in both planes and be reasonably sure it is square to the table.