On Apr 2, 6:10 pm, F. George McDuffee gmcduf...@mcduffee-
associates.us wrote:
On 2 Apr 2008 21:41:32 GMT, "DoN. Nichols"
wrote:



On 2008-04-02, Steve Lusardi wrote:
wrote in message
...
I have a Sherline vertical mill (the 5000 series) and I keep having a
problem with my aluminum workpiece pulling loose from the mill vise.
I have NEVER had very good luck getting the Sherline mill vise to hold
aluminum terribly well. Is this a deficiency of their mill vise?
Would a different mill vise solve the problem? Is it possible that .
010" cuts are too much?

I cannot imagine what you are doing to cause this problem from your
information supplied, but it is highly unusual. Please describe what you are
doing and how.

I don't know whether there there was more to what you posted --
both quoted samples that I have seen have not shown more, so I don't
know whether the following applies or not.

If the workpiece is sticking out of the vise by a height in
excess of perhaps four times the height of the jaw grip, then there is a
major problem with leverage working against you.

If you are trying to hold something withoutparallel faces
against the jaws, such as round stock stood on end in the milling vise,
there is a great chance that it will slip under cutting forces -- even
on a machine as small as a Sherline.

A rectangular workpiece is better held with the wide dimension
across the width of the vise, and the end resting on the bottom of the
vise.

A workpiece with an irregular surface in contact with the jaws
is more likely to slip, because there is really very little material in
direct contact with the jaws. This can be helped somewhat by putting
cardboard between the workpiece and the jaw surface so it produces a
larger contact patch.

So yes, more detail about the workpiece and how you are
attempting to hold it would help us to figure out what is wrong.

Good Luck,
DoN.

===============
Good observation/question.

I had assumed (and so apparently had everyone else) that the
problem was a rectangular part in the vise, for no good reason.

It may indeed be round, irregular, etc.

Question to original poster -- what is the shape of the aluminum
piece you are trying to clamp?

Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

Square workpiece.