In article ,
"DoN. Nichols" wrote:

On 2008-03-11, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-03-10, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

[ ... ]

Solid Criterion or Criterion-like bars turn up used around here for a
few dollars, but usually need some cleanup with a grinder.

O.K. I wish that *I* could come up with such steals.

It's a city thing, as we live off the residue of what had been a
technological civilization.

Well ... I'm pretty close to a city -- but not one engaged in
manufacturing of anything other than legislation. :-)

So, the necessary tool is a snowblower? Or a ****shovel.


And the Chinese are learning how to make these as well.

But -- are they learning to make them *well*?

Not yet, but they will soon enough. You remember when Made in Japan
meant junk. Now it's the good stuff.

Oh yes -- I remember my set of butter-steel drill bits. :-) This
was around 1961 or so, IIRC. But since I was driving them with a
hand-cranked eggbeater drill, they still served fairly well for my needs
at the time.

Yep. The Chinese will figure it out before the Indians do, it seems.


There are smaller bits than 0.125", which is far larger than needed to
cut a 10 tpi acme thread. In round numbers, if the pitch is 0.100",
then the tool width is something like 0.060", which can be made from a
piece of 0.1" drill rod, leaving ample space for a small setscrew.

With round, you have the problem of rotational positioning which is
locked in nicely with square tool bit. Of course, you could grind a
flat on top prior to grinding the Acme profile on the end.

Well, file a flat, before hardening.

Or -- use my surface grinder to grind the flat -- since I used
the surface grinder to grind the Acme profile with custom relief angles
for the particular thread pitch and diameter which I was cutting. The
final pass was grinding back the tip until it fit the Acme thread gauge
for width.

Surface grinders can be had around here for reasonable money, but no
place to put one.


Also covered above. Jewelers and clockmakers do this kind of stuff all
the time - same idea, but in miniature.

I could picture them doing it for small boring, but not for
internal threading, since jeweler's lathes typically don't have power
feed, let alone threading feeds.

All we want are their bits, not their lathes.

But you were saying "Jewelers and clockmakers do this kind of
stuff all the time" -- suggesting that "this kind of stuff" meant
internal threading -- and I was pointing out that they were unlikely
to be threading -- internal or external -- on their lathes.

I think clockmakers do cut threads.


The axis perpendicular to the bed ways is also loose, but far less so.

While my compound leadscrew was quite tight (and still is),
while the cross-slide was the one with 0.075" backlash (3/4 of a turn of
the crank).

Wonder why. Demands of production, I suppose.

Certainly. Remember that the lathe had a bed turret, so most
cutting was done with the tooling on the turret. The cross-slide was
power feed and used for parting off -- and probably nothing else -- so
it got used a lot, while the crank on the compound was likely used only
for fine tuning of cutter position vs a bed stop. Probably set up
parallel to the ways.

The Clausing does have the power cross-feed, but the top (compound) axis
is the loosest.


O.K. Let me define *my* terms so we can be talking about the
same thing:

[ ... ]

It's a logical system for sure. But honored in the breech, as discussed
below. This is why I try to say how far from the T-slot or bed way an
item is.

O.K. Most of the "breech" which I have experienced was in UK
references to lathes -- which would also call a 12" lathe (like my 5418
or your 5914) a 6" lathe -- rating it by the radius from the center of
the spindle to the lathe bed.

They would also be likely to call a "compound" a "top-slide" --
in part because some common lathes had the compound only as an optional
fitting, not as a standard part of the lathe.

Ahh. Interestingly, the Dorian Tool catalog of toolposts has an
annotated drawing of a lathe naming the various parts of said lathe.

And what names do *they* use? I don't have that catalog.

Moving up from the bed ways, the items are called the cross-slide and
the compound respectively. Same as your terminology.


On the 5914, the slide is flat-topped, not humped.

You mean the compound, not the cross-slide? I wonder why?

In the 5914 manual (page 30), that T-slotted part is flat-topped and
is
called the "Tool Post Slide" (704-033), and is dovetailed to the
"Compound Slide" (704-034), which in turn rotates upon the "Cross
Slide"
(704-032).

In the 5418 manual (page 19), that same part is humpbacked and is
called
simply the "Slide" (C-330), and is dovetailed to the "Lower Compound"
(DL-460), which rotates upon the "Cross Slide" (DL-458).

So, even within Clausing, the nomenclature varies. Thus the
confusion.

I think that the "cross slide" is a stable term, and anything
else is presumed to be the compound.

OK. As good a rule as we are likely to find.


O.K. if you are in doubt as to the correct term -- *ask* so we
can know that there is a possibility of difference.

Yep. Well, describe. What we have learned is that the nomenclature is
not uniform, so it is never enough to use the name; one must also
describe the part.

I still think that "cross slide" is sufficiently unambiguous.

OK. Perhaps that term is stable enough to be used without obsessive
explanation. What's above the cross slide seems to be the issue.



Remember that the traveling nut is shaped like a narrow but tall
quonset hut, and has a square bar bent into a very long and narrow 'U'
brazed to the bottom. The bar is inset into the base of the hut to
define the width like this (view with Courier again):

/// ///
____/// ///
/ /\/ /// -- part of long 'U' shape. U-turn is at the
/ / \ /// upper right and cut off in the drawing
/__ / \//
/ \ /|
/ () \ // -- this is the nut, and the top is not a meeting
/__ __\// of planes as shown, but rather a smooth curve
|__|__|__|/ which I can't draw with ASCII. Also the hole
shows as way too small.

And the bronze nut is silver brazed to the steel U shape.

Yes.

[ ... more trimmed ... ]

I think I visualize this correctly.


I'm going to Aloris as well.

The better way for almost everything. Unless you get to one of
those really expensive toolposts which let the tool holders lock at 15
degree intervals. :-)

Like the MultiFix.


I'm sorely tempted by a #22, the theory being that this replaces a
number of individual toolholders, and I'm more interested in flexibility
than simplicity.

Hmmm ... I would have to dig into the MSC catalog to figure out
a #22.

O.K. I see what it is now. It might be nice for occasional
tasks where a weird angle is needed, but for most purposes, I find the
BXA-16N to handle things nicely, with a pair of holders with straight
ahead mounted tools to cut bevels. The BXA-22 looks like a pain to
re-set in the middle of a task, so having it as the only one is not what
makes sense to me -- kind of like having a 3-in-1 machine where you have
to tear down the milling setup to turn a part needed for completing the
milling. :-)

Interesting. Why 16N versus plain 16?


I'm also sore tempted by a #5C, which accepts 5C collets and allows me
to utilize all those round shank tools.

Hmm ... I've got whatever the holder is which offers a 3MT
socket (matching the tailstock socket) which lets me put in anything
which I can use in the tailstock -- including drill chucks, of course.

I've thought of that, but I have lots of tools with cylindrical shanks,
especially boring bars.


I suppose I will outgrow the Clausing someday, but it won't be that
soon.

I don't think that I will -- unless someone gives me a Monarch
10EE or a Hardinge toolroom lathe -- and even so, I would probably keep
this for the turret and just keep the turret set up full time, instead
of the tailstock being set up most of the time.

It'll be a few years before the issue becomes salient for me. I'm still
chasing down causes of and cures for chatter.

Interestingly enough, the 5418 does not seem to experience much
chatter.

The latest observation is that if I pry the workpiece up wrt the
cross-slide, the workpiece moves far more than the 3-jaw chuck, so it
may be that the workpiece is too irregular for the 3-jaw to get a firm
grip on. This was discovered while I was trying to figure out why the
cutoff bar in the BXA-7 holder chattered so badly. This theory that
it's the workpiece will be tested. What will also be tested is cutoffs
using a collet chuck. I did tighten the various gibs a bit, to no avail.

Joe Gwinn