There does not seem to be a shoe the width of the slot that the grub screw can sit in which would firm up the rotational slack, as it were. So even when the grub screw has been tightened so it is a tight sliding fit in the 'keyway slot', there is still some rotational movement on the column assembly evident. The end of the grub screw on my machine has been reduced to a stub about 3mm diameter by the same deep. The grub screw screws onto/into what looks like a keyway slot about 8mm wide by 2mm deep. On the left had side of the head, adjacent the coil spring, is a grub screw locked by a hex nut that takes up slack in the column/spindle assembly.
Looking at the quill arrangement, it has a circular column which is wound up and down with an internal spindle which whizzs around and holds the tool which makes all the swarf, but it's the circular column that I am interested in here. It's a smaller brother of the Warco 'Major', the Axminster ZX30 and the Chester Eagle 30. I have a Warco 'Economy' round column mill, no longer offered by Warco but similar to those once sold by Axminster as the ZX25 and by Chester as the Eagle 25 (I think).
