First mount the body, base up, onto the milling machine table using two 321 blocks
or suitable parallels, Photo 4. Fully tighten one of the two clamping nuts but only
lightly the second just in case there is a minute amount of twist in the surface.
Because of that add an angle plate at one end for added support and machine the two
faces so that the machining forces are towards that end. As a cut of 0.2mm deep is
all that it needed it is probable that adding the angle plate is being over cautious.
Even so, when mounting items for machining on the milling machine caution is always
a good thing. The setup for all four vices will be essentially the same.
Now that the bottom faces are machined remove and check to see that there is no rock
when standing on the surface plate, or use the mill table if a surface plate is not
available. Any minor errors should be removed by scraping.
The faces on which the jaw slides
Next machine the face on which the jaw slides, Photo 5. This being one of the easier
tasks, but with the base of the vice having been machined parallel with this surface
in the last operation, remove only the minimum amount to achieve a fully machined
surface, hopefully, no more than 0.05mm. When done, do test using the setup shown
earlier in Photograph 2 you should be looking for a variation of no more than 0.03mm,
preferably better. Again the four vices will be machined with a very similar setup.
The moving jaw
It is necessary now to carry out some work on the moving jaw as a dimension from
this is required with the next operation. The task is to machine the surface on
which the jaw plate fits and the surfaces that slide on the base. The jaw face must
though be at right angles to the face which slides on the base, ensuring that the
jaw will eventually mate accurately with the fixed jaw.
Add the jaw to one side of the workshop vice as shown in Photo 6 and machine the
jaw plate face, machining up to the step existing for the present jaw plate. Note
that the jaw being machined is also firmly up against the side of the vice, theoretically
achieving both requirements. However, the face which slides on the base may not be
perfect and need lightly skimming.
Therefore, remove and return to the vice, this time the face just machined against
the vice's fixed jaw and the step mentioned above resting on the top of the jaw.
Then machine the two faces either side of the central portion. Again, do remove only
just enough to achieve fully machined faces else misalignment of the closing screw
with the hole in the jaw may become a problem, though not unsolvable. The process
will again be the same for all four vices.