One problem with budget import machinery can be ‘slop’ or ‘backlash’ in the
shafts controlling the table. With dials fitted to the handles, this can lead to errors
in positioning the work accurately. My milling machine had about 1mm of slop, even
with the adjusters done up tightly.
Professional readouts or D.R.O.’s as they are called can be very expensive but there is a
budget version suitable for home workshops. It works on the same system as digital vernier
calipers and is more than adequate for its intended use.
The silver boxes, one at the rear and one on the left side of the front apron house the two linear measuring devices which record the actual position of the table. With these fitted, it does not matter how much slop there is in the shafts, the position displayed will always show the correct point.
The positions for left/right (X axis) and front/back (Y axis) are displayed on the readouts above. The system is accurate to 0.01mm and works very well. These boxes are magnetic and can be stuck anywhere required.