Subject: Re: Enco 4" Milling Vise

From: Mike Rehmus <[email-masked]>
Date: 23 Apr 1996 16:12:35 GMT

The interesting thing you might like to know about the
'high-quality' vises is they are far from perfect.

The spec on a Kurt is 0.001, I assume plus or minus.

They grind many Kurt vises at a single time and the
potential is there for some inaccuracies.  If one
takes a Kurt to a good grinding shop, they can be
ground into 0.0001 alignment for a little while.

If you ever notice the center of the ways on a Kurt
or other vice, see how they discolor?  That is because
the way becomes hollow or 'U' shaped over time.  A
good grind job will clean that up and prevent it from
reforming if - if - if the vise is well aged before hand.

Even with Kurt or the other 'quality' vices, the work
does rise a bit when the jaw is tightened.  On my vise,
at least, there is an adjustment on the back of the movable
jaw that can me set to minimize rise.  However, if it is
adjusted to remove all rise, the jaw will no longer move.

It is always advisable to tap the work down as you tighten
the jaw.  Otherwise, at least with the ten or so quality
vises I've used, the last 0.001 of squareness will not 
obtainable.  And once in a while, 0.005 is a problem.

I'd guess this is why good fixtures positively hold the
work in all planes.

Best regards,

Mike Rehmus

---

From: [email-masked] (Edk4)
Date: 23 Apr 1996 17:38:31 -0400

>reforming if - if - if the vise is well aged before hand.

Ah ha!  *That* explains the 'stains' I've noticed on my 4" Enco. I
couldn't imagine what the heck it was. No amount of cleaning and oiling
made any difference. 
Mine, however, must have been pre-aged, because it arrived that way.

I've been thinking about machining a pair of 'soft' steel jaws, in situ,
with a small ledge at the bottom of each one to hold the parallel - not
depend on the ways at all. This make any sense to anyone, or not? This
way, I should have a reasonably accurate 'hold', as long as the jaws don't
get dinged-up.

Would it make any sense to (down) taper the moving jaw slightly to
compensate for the 'lift', or am I making things unnecessarily more
complicated (worse)?

Sorry to hear that Kurt is 'less' than perfect. I'd always hoped to have
one someday, along with nothing but Albrecht chucks. First the Easter
Bunny, then Santa Clause ....

Did anyone buy one of the 0-3/8" keyless chucks that Enco had on sale last
month?
I got one of the 0-1/2" and a 3/8". The 1/2" appears to actually be that
elusive Enco bargain, but there's axial play in the jaws of the 3/8"
(which is made quite a bit more cheaply than the 1/2") and it has a fair
amount of runout, presumably because of the play. Anyone else take the
bait?

------------------
Ed Kingsley

---

From: [email-masked] (Stephen Gaudio)
Date: 25 Apr 1996 10:04:39 GMT

>ground into 0.0001 alignment for a little while.

under a handful of warm chips, you can kiss those tenths goodbye.

>reforming if - if - if the vise is well aged before hand.

what is considered 'aged' and/or 'seasoned' steel? as far as i know,
99% of the 'aging' is accomplished a few minutes after pouring.

>adjusted to remove all rise, the jaw will no longer move.

Kurt is famous for their angle-lock: the movable jaw is forced down as
much as toward the fixed jaw when tightened. the movable jaw floats
angularly about the vertical axis, to firmly clamp parts whose sides
are slightly out of parallel (horizontal taper). 
but i have never noticed any displacement vertically.

perhps your workpiece is rotating up because the clamped faces are out
of parallel (vertical taper). to be sure, place a cylinder (axis horiz)
between the workpiece and the movable jaw. now the fixed jaw face establishes
orientation (there's no arguement between the jaws)

a clean Kurt vice is just about the only thing i'll trust on a milling
machine. i'll blame table error before i point a finger at the kurt.
(although the ways may be good to under a thou, the *angular* error
(pitching, rolling, yawing) spawns errors on the order of a thou for
anything but the newest, high quality machines. don't be sidetracked!)

i hate those cheap vices. they can't even paint the damn things right.

ranks up there with pink shop rags and buggered threads on fixure studs.

steve.

---

From: [email-masked] (James D. Szura)
Date: Fri, 26 Apr 1996 06:00:19 GMT

>Mine, however, must have been pre-aged, because it arrived that way.

I believe the black is iron oxide that has formed in an oxygen poor
environment, it will actually prevent the iron from rusting and it
won't hurt anything.

---

From: [email-masked] (David Erickson)
Date: 2 May 1996 03:52:34 GMT

Earlier in this thread, someone mentioned the 4" vise on sale at MSC
for $59.  I bought a pair of these, and they are nothing short of
fantastic for the price.  The jaws are about .001" out of plumb on
one and perfect on the other.  The movable jaw has an internal wedge
which pulls the jaw down as you tighten, and is adjustable at the
back end for clearance on the ways.

I did find some what I think are minor problems:

the vise needs to be completely dissassembled and cleaned and oiled.  There
was grit inside the spindle bearing, and the internal wedge has a half
ball bearing which needs some oil to do its wedging.

the setscrew at the back of the movable jaw would not stay put, and
the jaw kept losing its adjustment, so I replaced it with a bolt with
a locknut

the T bolts that attach the vise to the circular base are threaded
1/2"-12!!  Just try and find a replacement nut.

the spindle bearing has no thrust ball bearing, just a thrust flange
with no seal, so frequent cleanings and reoilings are a good idea.

--
-----------------------------------------------------------------------------
David Erickson    Technical Support Engineer    Rational Software Corporation
email: [email-masked]
-----------------------------------------------------------------------------