Harold Hall
An alternative setup
Having machined the jaws as above I realised that for some this may be the workshop's first vice and not having another vice available. Photo 7 shows an alternative using what I call “square squares”, as opposed to circular squares, workshop grade of course.
To make these, take two pieces of square material (25mm Sq. would be about right)
and say 40mm long. Place one in the four jaw chuck checking to see that all four
sides are at right angles to the chuck's face using a small engineer's square. Face
the end and drill through with a hole size to suit the clamping stud size used on
the milling machine. Turn over, check that it is square once more and face the second
end. Repeat for the second one, but making this the same height as the first, at
least within +/-
Now, add one to the mill table and set its front face parallel with the X axis (left right) of the machine and secure. Place the two adjacent jaw faces securely against this, also fitting the second square square and secure. Make some bar clamps, or use toolmakers clamps, and machine the surface for the jaw plate. The jaw can then be removed and with the face just machined against the “square square's”, and the small step resting on the squares top face, machine the faces that slide on the base. Doing this generally as explained if using a vice.
The face on which the keep plate slides
The next stage is to machine the faces on which the jaw keep plate slides as shown in Photo 8. This, from the photograph, looks a relatively straight forward set up but that is not totally the case. The clamps are acting on the surface under the vice jaw and under the portion threaded for the closing screw at the other end. Unfortunately, these are lower in this setup than the 321 blocks and some packing needs to be added to them so that the clamp can act on them.
The surfaces are also rough cast and not level so localise the clamping point by using a narrow packing piece, Photo 9. Note how the height of the other end of the clamp is adjusted by a nut on a stud, the stud being supported by a tee nut in the tables tee slot, just visible in photograph 8.
The thickness of the portion being machined is important as it must be a little less than the height of the raised portion of the moving jaw. As on some of the vices there was clearance between the jaw and the keep plate it may not be just a case of skimming the surface to give a good finish. More may need removing.
Therefore, measure the height of the central portion of the jaw and then work to this dimension, say minus 0.2mm to 0.4mm, its not critical at this stage. To measure the result as machining is taking place add a piece of steel of known height and measure the total height. From this the actual height being achieved can be calculated. Photo 10 shows the process using a micrometer but a calliper would be equally suitable for the task.
Metalworking
Workshop Projects
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