Tramming the Router or Spindle (Making Sure it's Perpendicular to the Table)
Tramming the head (spindle or router) of a CNC router can be done with a simple old machinist trick using a long bar bent in a special way so that you can very accurately ensure the router or spindle is perpendicular to the bed (table) of the CNC machine.
TableCheck from Patrick Hood-Daniel on Vimeo.
Thanks to one of my customers , Mike T., you can check and adjust the perpendicularity of the router or spindle (head of the machine) to the table bed. This is also called tramming the CNC router or milling machine. This technique can be done with most milling machines, CNC machines and CNC routers.
Typically, machinists these days will use a dial indicator to measure the error by extending a dial indicator along a bar that is perpendicular to the collet of the spindle. If you don't have a dial indicator, the same level of precision can be achieved using a long bar bent in a way so that one end can be inserted into the collet of the spindle or router, and the other end floats along the surface of the table.
To ensure that the measurement is done successfully, the table must be flat. If the table has not been surfaced, make sure to do this first. Also, make sure that the rails are straight. If your table is sagging, or exhibits any curve at all, tramming will be only as good as the flatness of the overall table.
Thank you Mike for creating this very simple to understand explanation!!