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Posted by on April 2, 2008, 4:08 pm
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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?
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Posted by Alan Wright on April 2, 2008, 4:42 pm
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> 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?
There has been mention of this on the Sherline Yahoo group lately,
following extensive discussion and evaluation of Sherline chucks
with holding problems.
It appears that (assuming you are using the vise properly) you have
a defective vise. As best I can remember, mine has never let a part
loose even once in several years of use. It grips as well or better than
comparable models you could replace it with. .010" cuts are very
conservative in 6061.
I wonder if people use the trivial procedure of yanking on the
workpiece after gripping it in the vise. I've never had a workpiece
come loose from any vise on any mill if I could not pull it loose
by hand. I also do the obvious things like gripping enough of the
part (probably always 1/8" or more), and always either gripping
in the center of the vise or using a spacer on the opposing side.
If such practices do not yield perfectly reliable hold, then I have
to believe the vise is defective.
Alan
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Posted by Alan Wright on April 2, 2008, 4:47 pm
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>
> > 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?
>
> There has been mention of this on the Sherline Yahoo group lately,
> following extensive discussion and evaluation of Sherline chucks
> with holding problems.
>
> It appears that (assuming you are using the vise properly) you have
> a defective vise. As best I can remember, mine has never let a part
> loose even once in several years of use. It grips as well or better than
> comparable models you could replace it with. .010" cuts are very
> conservative in 6061.
>
> I wonder if people use the trivial procedure of yanking on the
> workpiece after gripping it in the vise. I've never had a workpiece
> come loose from any vise on any mill if I could not pull it loose
> by hand. I also do the obvious things like gripping enough of the
> part (probably always 1/8" or more), and always either gripping
> in the center of the vise or using a spacer on the opposing side.
> If such practices do not yield perfectly reliable hold, then I have
> to believe the vise is defective.
>
> Alan
>
One other note: these vises (i.e. screwless type) can pretend to
be tight when they are not. They will appear to tighten because
they are engaging the wrong notch underneath, and thus at full
tightness do not yet contact the part. However, in such case
the part will be loose to the touch. It is imperative to unscrew
the thing far enough to engage a notch far enough in to tighten
on the part. This should be apparent to anyone who has tried
one, but thought I would make sure.
Alan
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Posted by Steve Lusardi on April 2, 2008, 4:52 pm
Please log in for more thread options 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.
Steve
>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?
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Posted by DoN. Nichols on April 2, 2008, 5:41 pm
Please log in for more thread options >>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.
--
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
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> 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?