In article ,
"DoN. Nichols" wrote:

On 2008-03-18, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-03-14, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

[ ... ]

But the site does well with Opera on the Sun, after I turned on
cookies, JavaScript, and Flash. :-) I'm still downloading catalog
sections. Downloading "Cut-Off Systems" at the moment. I'll probably
skip the "milling systems" and "indexable drill systems" catalogs.

I haven't tried Opera recently, because when I first tried it, it
crashed my Mac, and also it lacked the ability to work through a proxy.

Hmm ... how long ago was it? The current one has the ability to
work through a proxy -- even on a site-by-site basis, just as you can
turn on JavaScript and the like on a site-by-site basis.

A few years. But it takes many years for me to try something again,
when it was originally vastly oversold. Usually the perp dies first.


I do notice that they have cut-style knurling tools which are
particularly nice -- low-force tools for cutting instead of embossing
knurling into a workpiece.

I looked at that too, but someday.

I've got a turret-mount version of the cut knurler. It looks
like a 3-jaw chuck on a Morse taper, but the jaws have tall extensions
on the arms, with each extension holding a tilted cut knurler. I intend
to try that next time I use the turret for producing the microphone
adaptors.

OK.


I find the straight-ahead tool holders on page A-91 called:

MTENN TOOLHOLDER
Style E - 30° Side Cutting Edge Angle
for negative triangle TNM_ inserts

though mine are a different brand ISCAR? Valenite? One of those.

Or just use the side of a triangle insert by angling the compound?

The whole idea is to *avoid* angling the compound or the
toolpost if at all possible. I normally only change it if going from
right-hand to left-hand thread cutting, or going from standard 60 degree
threads to Acme threads. The basic idea is to have the toolpost
properly set so threading inserts and parting tools are at the right
angle. For that matter, it also applies to knurling tools.

OK.


BTW While I was down there I checked the bearings of the DuMore
toolpost grinder, and find that my relubrication of the bearings
seems to be holding up nicely.

Hmm. Another project for me.

Of course, your bearings are the spindle ones, not the motor
ones. But I worked some Starrett "Tool and Instrument oil" into the
bearings and that smoothed things up nicely -- and they seem to be
staying that way.

The same lube might do for your spindle bearings, too.

Meaning the Clausing 5914 spindle? That's DTF24.

No -- meaning the spindle on your toolpost grinder, which I seem
to remember had bearing problems in the spindle, not the motor as I was
experiencing.

I wouldn't be surprised if DTF24 worked for DuMore spindles as well.


I bet the BXA-22 repeats pretty well, but it cannot be so good as a
block of steel. Nor can it be as rigid.

And in particular if you are loosening the clamp screw and
changing the insert angle frequently.

But the riffled clamping surfaces should cause accurate alignment to the
nearest 15 degrees.

*If* a chip doesn't make it in there as you are changing. :-) I
would rather set this sort of thing up *once* per project instead of
changing angles in mid-project with the likelihood of needing to return
to the same setting.

Well, one must always clean mating surfaces to keep chips out.

Yes -- but that can be difficult with the multi-angle tool
holder (the BXA-22) when changing in the middle of a project -- and
changing back again for the next part. To be sure, you have to remove
the holder from the toolpost, then unscrew the screw which holds the
insert arm, set it aside, clean the radial serrations, and then
reassemble it -- without dropping some crucial part into the chip pan of
the lathe.

Given that the ripple pattern is radial, it should locate in both angle
and location well enough.


I'm not visualizing this. The pancake nut cannot be brought down far
enough to matter, and so I adjust by hand every time. A little bit
(maybe 0.25") of the holder projects above the BXA toolpost. It doesn't
seem to matter.

Oh -- the block needs to be *higher*, not lower. In cases like
that, I've set the pancake nut on top of a 1/4" lathe bit (which is
nicely ground to 0.250") so I can get a repeatable height with a tool
which requires an unusually high setting. (IIRC, that was with a
threading tool held upside down for threading in reverse off the end of
thin-walled tubing.

Using a 0.25" square bit would have worked, as would a 0.250 spacer
plate between compound and toolpost.

Hmm ... the spacer plate would work -- if you knew to install it
before you started the project. :-)

WEll, it would become a permanent part of the setup. The BXA toolpost
has a 3/8" (by eye) blind hole in the bottom, clearly intended for an
anti-rotation pin. So such a spacer plate would have a ridge below and
a 3/8 hole to accept a short 3/8 dowel rod.


BTW -- I note that the BXA-4 does not specify how far the
centerline of the bore is from the dovetail, so the are not promising
that you could use a set of them as a replacement for a turret. :-)

Right. Aloris' turret replacement is the "Indexable" line.

Well ... that is their replacement for a turret *toolpost*, not
for a bed turret which is what I was talking about. Set the cross-slide
so the bore though the boring bar holder is concentric with the spindle,
and use that to hold the various turret tooling. And if they are truly
the same distance from dovetail to the center of the bore, you could
have multiple tools set up and just change them -- at least until you
need to use the cross-feed to part of the workpiece, after which you
have to re-establish the centering again.

I'm sure that the claim is that this is almost as good as a turret, but
a fraction of the cost.

I'm sure that they would *not* claim that -- as this is using
the tool and holder in a way for which they were not designed.

And it lacks the per-station stop bars so each station stops its
feed in the right position.

The indexable toolposts do indeed have a positive locking system to
ensure angular accuracy.

That is *angular* accuracy -- not the longitudinal accuracy
provided by the turret stops on the bed turret. As you rotate the
turret to the next station, it rotates (though a pair of bevel gear) a
plate on the tail end of the turret ram which has the same number of
tapped holes as the turret has stations. In each hole is a long piece
of allthread, with a pair of flats for a special crank wrench on one
end. The one which is on the bottom hits a projection on the base when
you go far enough forward to prevent more motion. There is a setscrew
coming in from the edge to keep the long screw in position during a
project. So -- once you have taken the time to set it up, you get each
tool stopping at the right position.

The Dorian and Aloris setups ought to be able to achieve reasonable to
good longitudinal accuracy. Not that I've actually tried this, or will
anytime soon, but the design is plausible.


As an example, on my typical run,
I have the following setup:

1) Combination end stop and extendible center drill. The
workpiece is slid forward in the collet, then the collet is
partially closed to add drag and the turret is moved (with the
end stop in contact with the workpiece) until the turret stop
for that station is hit. At that point I push the collet lever
to lock the workpiece in place at the desired extension, then
start the spindle and extend the center drill so I can center
drill the workpiece.

2) I withdraw the turret fully away from the headstock and it
rotates the turret to the next station. I then bring it
forward, and the drill in a chuck drills the end of the stock to
a preset depth.

3) Again, the turret rotates on full withdrawal, presenting a
station with a tap in a releasing tap holder. At this point,
the depth stops really become important. The first stop defined
where the end of the workpiece stock was. The second stop
defined the depth of the drilled hole. The third stop stops the
motion of the turret ram during tapping, causing the tap holder
to release and the tap to spin freely with the workpiece.
Without this the tap would be likely to hit bottom and break off
in the workpiece. I intend to use thread forming taps the next
run so I don't have to drill the tap hole quite as deep.

4) The next turret station contains a T-style knurling tool (or
later will contain the cut-style knurling tool), and knurls the
full length of the workpiece to be made into the part, plus a
little overshot. The stop is not critical there, but it helps
to speed up the operation.

5) The next station contains a "roller box tool" (A turning tool
with a built in follower rest), and reduces the diameter from
3/4" to 5/8" in a single pass. Again the stop for that station
defines how long the reduced diameter is.

6) The final turret station contains a Geometric die head. The
head threads the reduced section to 5/8-27. Here again, the
stop setting is important so the die head releases at the right
point so the thread is as close to full length as possible
without running into the shoulder.

7) At this point, the turret is fully withdrawn again, indexing
around to the first station ready for the next part.

8) And the carriage is now moved to the right point using a
clamp-on bed stop, locked, and the cross-feed engaged, parting
off the part while I hand file a bevel on the end of the
workpiece, the leading and trailing edges of the knurled full
diameter part, and then move a wire basket to catch the
workpiece as it falls off.

9) If I still have enough stock in the spindle, I got back to step
one to make the next part.

Bear in mind that each turret tool has a different extension,
with the worst being a #7 drill bit in a 1/2" Jacobs chuck in a station.
The releasing tap holder is probably next in length. The shortest two
are the box tool and the Geometric die head.

Now -- I *do* have a bed stop with a turret of its own which has
four stops. But that is not enough stops for the needed six stations so
I would be more limited with what I could do if I were using turret
tooling in the quick change toolpost. And certainly the mass and bulk
of some of the turret tooling would be enough to prevent an indexing
toolpost from rotating freely.

All this is certainly way more complex that one would try with an
indexable toolpost system. That said, there are plenty of applications
where an indexable toolpost will more than pay for itself.


OK. MSC still has Cleveland cutoff blades, on page 626 of the 2007/2008
catalog.

O.K. I could not find them in the web page -- it suggested that
they were discontinued -- from Cleveland, or from their stock, they
didn't say. :-(

That's their generic response to a failed search.

O.K. But it did find some of an import brand which were of
similar design.

If the search failure was egregious, I would complain. MSC is quite
responsive to such things. And people really do read and respond to
those little post cards.


Right. I do need a large center drill anyway. The lathe came with a
Royal live center.

O.K. I got a set of five of different sizes in a nice screw-top
wooden holder so I've got some from 1/8" to 1/2" major OD. Each has its
uses.

Yes. I've seen those sets. I'll probably buy new here, as what I've
seen come up used is in bad shape.

I bought new -- twice. One to keep near the Clausing, the other
to keep fairly near the Compact-5/CNC and the drill press.

Matches my experience.


Joe Gwinn