If the available traverse of the vertical slide does not enable you to machine both
sides at this setting, as in my case, fit and set the saddle stop so that the casting
can be turned over and the other side then machined at the same level. The viewer
having a lathe only workshop should equip the lathe with a saddle stop as I do believe
one is all but essential for milling on the lathe.
With the base now machined it can be returned to the slide without packing. Fix,
using screws through the vice's own fixing slots at the lower edge and bar clamps
above, making sure that it is reasonably horizontal. Machine the four faces, that
is, outer and inner ends.
Whilst I prefer to use tipped tungsten tooling on the outer surface of cast iron,
using their outer cutting edges to machine the inner and outer surfaces of the ends
will present excessive load on the vertical slide if wide cuts are taken. Do therefore,
step the cutter down each face about 3mm at each pass, then, using an high speed
end mill, take a very light finishing cut, Photograph 4.
Having machined both sides of the jaw at this setting they will be parallel. This
enabling a square to be used off the outer face for setting up when in use. Whilst
still on the slide also machine the surface on which the jaw will eventually slide,
Once more, reverse and mount the casting on the slide with the two top faces against
the slide's surface. With two T nuts in the lower slot place a stud in each one and
with a washer and nut lock them onto the slide's surface, doing this at a pitch of
1 9/16", the pitch of the vice's fixings. The next stage is to make the slot in which
the jaw will slide. An essential requirement for this is that the slot must be at
right angles to the fixed jaw. As this has already been machined some means of achieving
this objective is necessary. For this purpose, mount a short length of steel onto
the slide's surface setting it accurately using an engineers square off the lathe's
bed, Photograph 6. A workpiece clamp, as shown, will be ideal
Now, use a toolmakers clamp to hold the vice jaw against this and clamp the casting
to the slide using two nuts on the studs and two bar clamps above, Photograph 7.
It is essential that the four fixings must be progressively tightened so at to avoid
the casting tilting, it would though be preferable that the top clamps were longer
than shown on the photograph so that they held the casting nearer its centre.