Carry out preliminary machining, sides and bottom, for the area where the jaw keep
plate will fit followed by the slot in which the jaw will slide. Despite the jaw
having limited movement the slot runs the complete length of the casting. Centralising
the slot on the drilled holes will ensure that it is adequately central, not easy
to measure by other means. With the slot finished, return to the keep plate slide
and finish mill both base and sides of the groove.
This is not an easy item to mount for machining due to its small size, irregular
shape, and taper that runs from the working face back. Mount the angle plate onto
the slide and onto this mount two supports for the jaw. These are positioned against
the web on the bottom of the jaw that eventually will slide in the slot in the vice.
The web is tapered as mentioned and the support pieces are angled to suit, Photograph
8. The jaw is then held in place using a bar clamp mounted from the angle plate and
its working face machined.
Now with a flat face the jaw can be reversed and easily mounted directly onto the
vertical slide using two bar clamps and the available surface machined. Place a piece
of close fitting bar into the lower tee slot to act as added support for the jaw,
thereby preventing the jaw from being pulled from the clamps holding it. This simple
bar really is an essential piece of kit for the vertical slide and will see many
uses, see later Photographs 12 & 14.
Next, mount the jaw and machine the web, Photograph 9, making it a close fit in the
slot in the body, but a little on the tall side. Note the rear support also being
used in addition to the bar clamp.
Now, using a micrometer, measure the distance from the face on which the jaw is to
slide to the face on which the keep plate is to slide. Add to this, say 0.002", and
with a suitable piece of metal and a feeler gauge or two, or three, create a pack
to this dimension. With the jaw still on the vertical slide, place the pack onto
the sliding face of the jaw and using the saddle carefully bring it up to the cutting
edges of the end mill and lock the saddle. Check that the pack will just move without
play. At this setting machine the face on which the keep plate will be mounted. If
you have slip gauges they would be even better. Do though aim to be on the high side,
you will file a little off later.