I cannot see John how a tilting vice
could be used satisfactorily to machine a Keats angle plate, even
using a robust vice.

Incidentally, the site now runs to
almost 350 pages and includes 50 workshop projects and 20 workshop
processes, with many more to follow over the next few months. These
will be most of the articles I have provided in ME and MEW.

Harold

Edited By Harold Hall 1 on 22/09/2011 16:37:18

Edited By Harold Hall 1 on 22/09/2011 17:06:31

Sorry John for having been slow in
replying to your question.

This is a very difficult question to
answer as there are so many variables so can only give a few pointers
and will start with castings.

Do remove all the high spots on the
face to be placed on the faceplate, machine table or angle plate.

Even with that done the face will be
far from perfect so place a piece of thin hard card between the
workpiece and mounting surface. Sheet copper is often mentioned but
is expensive and card is freely available. This will increase the
contact between the surfaces.

However, contact will still not be
perfect so do make sure, if possible, that the end of the clamps
being used are well in from the workpiece’s edge which does in some
cases fall away. Say at least 10mm. I think this is possibly one of
the more likely causes of the problem

The packing end must be higher than the
workpiece, but only just, say plus 1mm. Much more, especially with a
short clamp, and the clamp stud will have to approach at an angle so
that the nut/washer sit cleanly on the clamp surface.

If you are using clamps with jacking
screws, as I mostly do, above say 40mm workpiece thickness, add and
tighten a nut against the clamp to make the assembly more ridged. If
the clamps have a clearance hole, add a nut below and above for the
same reason.

With multiple clamps, gradually tighten
each one in turn.

In particularly difficult situations,
if possible, add supports around the base of the workpiece.

Avoid using multiple pieces of steel,
etc. to make up the packing height. If you have to do this make sure it is
stable. Don’t do this on the faceplate!

Try, wherever possible, to have the
angle plate horizontal in the bench vice whilst mounting the
workpiece, then moving it to the machine.

If securing a more regular item, rather
than a casting, you should not need the card packing, otherwise the
other comments all have some relevance.

I would like to think that I have
solved your problem, but I am not confident, however, the above
should provide a starting point.

Harold