On 2008-01-01, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:
On 2007-12-31, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:
[ ... ]
What *I* have is labeled with an EMCO tag, with no clues
whether it was made by someone else. I have seen a set of the same size
[ ... ]
Emco also made a different version where the T-slot in the
holders is off center, and a T-headed bolt runs through the block
(clearing the center bolt) with a nut on the opposite side to lock the
tool holder down. I've never seen these except in the service manual
for the Compact-5/CNC.
So, Emco is another possible source.
Note that is *Emco* -- not *Enco*. Emco is the Austrian maker
of lathes and milling machines which made my little 5" CNC lathe. They
used to make a matching manual lathe, but no longer do so.
I was reading it as Enco. Oh well.
That is what I was afraid of. It is a pity that the two names
are so similar.
[ ... ]
I don't think this toolpost came with the lathe, as it is cobbled to the
lathe.
Note that when you get a new post -- even from Aloris -- unless
you have paid extra for the mounting plate to be specifically machined
for your lathe (in which case you will need to feed them information
about the lathe's T-slot), you will receive a blank mounting plate,
which you will need to mill to the proper dimensions for *your* T-slot.
Usually, this simply requires changing something like this:
/ /
/ /
+----------------------------------------+
| |
| | /
| |/
+----------------------------------------+
to something like this:
/ / / / / /
/ / / / / /
/ +------------------+ / / /
/ | |/ / /
+----------+ +----------+ /
| |/
+----------------------------------------+
So it will slide into the T-slot, leaving the height of the center just
a little below the top of the compound when it is pulled up as tight as
it can be. There is a pre-tapped hole in the center of the plate which
accepts the mounting rod on the toolpost.
Is the above plate what becomes the big T-nut that goes in the big
T-slot on the top of the compound rest?
That is correct. It comes as a blank with a new toolpost (at
least so with the new Phase-II toolpost, which is the only post which I
have had new.)
If so, it came with one of
these. It looks shopmade, by someone with a vertical mill. The T-nut
screws onto a piece of 5/8-18 UNF threaded rod that goes through the
toolpost body, a spacer, and a hex nut. The big problem with the
shopmade T-nut is that the 5/8-18 thread is not quite perpendicular to
the faces of the T-Nut, and so the nut wobbles visibly on the rod. The
rod threads are damaged, and the rod may also be slightly bent. So they
had the mill, but perhaps not quite the skill.
Hmm ... the Phase-II has a metric thread which is quite similar
to your 5/8-18 -- probably a 16mm thread. And the plate comes
pre-tapped in the center of the plate -- but you do have to mill down
the plate to make it into a 'T'.
What appears to be missing is the shallow "T-nut" plate that goes
between the top of the compound rest and the bottom of the toolpost
body, and has a series of 8mm holes to accept the index pin. I assume
that this plate also serves to space the toolpost up to the correct
height with respect to the spindle axis.
Did you see one in the Dickson catalog? (I got there too late
to download it, so I don't know what it has. Probably there is a new
one up by now. :-)
But my guess that the pin served for an index was assuming that
it was spring loaded and did not project very far. Looking at the
images from the Toolmex catalog, I see that there is a pin which goes
all the way through the body of the toolpost -- which suggests that it
is expecting a hole to be drilled to accept it for setting it properly,
but that won't work on a compound like what we have on the Clausings,
because those can be set to any angle. You might drill a hole to match
the pin at the single most common setting (on my Clausing and Phase-II
toolpost, that would be at the 29-1/2 degrees for right-hand threading.
However -- my Emco clone of a Dickson does *not* have such a
pin, and there is where such a pin would be most useful, since the
toolpost mounts directly to a steel plate on the cross slide, and it
can't be set to other angles.
As for the height -- that is handled by the nuts on the screws
on the tool holders -- so each is set to the proper height for its own
tool. I somehow doubt that you would need to block up the ToolMex or
Dickson on the Clausing compound.
But -- perhaps you should get some stock of the proper thickness
and size and make your own T-nut with the threading being done in the
lathe -- mark the center by scribing a pair of diagonal lines between
opposite corners. Hold it in the 4-jaw chuck and adjust so that
intersection point is truly on center. Then center drill for a start,
drill through tap drill size, and using the live center in the center
hole in the back end of the tap, drive the tap with a wrench as you use
the live center to push it. I would use a gun tap if available, to
avoid having to keep backing up the center and the tap to break chips.
Once the hole is on center -- and truly perpendicular to the
plate -- then mill the sides to make it into the right size T-nut. I've
done this to make a spare T-nut with the right post threads to allow
mounting a toolpost grinder on the compound. And *that* I also needed
to make a spacer cylinder to start it off at proper center height to
save time during subsequent setups. (I haven't actually *used* the
toolpost grinder yet -- but it is now ready for use. :-)
[ ... ]
I'll keep an eye out for BXA posts and holders. What's a reasonable
price?
There *is* no reasonable price in my opinion (as a retired
hobbyist on a fixed income) -- especially for a genuine Aloris. As a
result, I have a set of Phase-II wedge style which I got when they were
[ ... ]
Note that AXA size holds up to 1/2" shank tools, while the BXA
holds up to 5/8" shank tools -- and that extra 1/8" does make a
difference in rigidity.
Yes. Rigidity varies as the cube of the critical dimension (diameter in
this case), so (0.625/0.500)^3= 1.95, call it twice as rigid.
Well ... since the shanks are square, there is no diameter here,
but that is close enough. :-) Probably a little more strength for the
corners which would be missing in a round shank -- but pretty much the
same for both sizes of square shank so the ratio is probably the same.
I've also picked up some interesting Aloris only tools,
including a very nice knurling tool in which the knurls are held in two
arms which move on a vertical dovetail, with a leadscrew coupling them
with a left-hand thread for one and a right-hand thread for the other,
so they maintain the centering on the axis (once initially set), while
you adjust the spacing for the size of the workpiece being knurled. The
knurls apply to the top and bottom instead of having to be pressed in
with the cross-slide, so the load forces on the machine are much less
than with the common "bump" style knurlers -- which are often supplied
as part of an Aloris or Aloris-style kit. Those are mostly useful for
facing, using the half-toolholder in the other end. :-)
I think I need an Aloris catalog, to know the options and their prices.
That will tell you the options -- but I don't think that you
will find prices. For that, I use my MSC catalog as the reference. (It
also has a pretty good listing for all of the options available.)
Enjoy,
DoN.
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