On 2008-02-03, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-02-02, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-02-01, Joseph Gwinn wrote:

[ ... ]

Understood. I'm just wondering how long a thread your ring can
have. IIRC, I measured mine at 1-1/4" OAL from the face of the
headstock, so possibly 1" of thread engagement.

I'll measure it next time I have the collet holder out.

O.K. But you don't need the collet holder out to duplicate the
measurement that I did. I measured the length from the face of the
headstock to the end of the ring, not the internal thread length.

It's a hair under 15/16 of an inch: 0.926".

O.K. That makes the difference -- your ring puts the stress on
fewer threads.

[ ... ]

I suspect that it is turned (and finish ground) from a rather
tough steel, but that no attempts to harden it after turning have been
done. That risks warping too much. So -- it should be harder than
12L14, but probably something like 1040 I think.

Or rough machined, hardened, and ground to final size? But ~1040 steel
is likely in either case.

Yep. Lots of places to grind -- starting with the OD of the
bearing seats. BTW -- I've got evidence that the spindle is *not*
hardened. When you pull the spindle (to change belts) you have to file
off the ding left by the setscrew on the bull gear before re-assembling
it.

I now have a set of new belts, so I'll soon have a report.

O.K. I thought that the 5900 had the belts outboard of the
headstock (under the gear cover), so you don't have to remove the
spindle to change that. My 5418 has three belts in parallel between the
spindle and the layshaft in the pedestal.

I would be tempted to file a small flat, so the setscrew ding doesn't
interfere with future removal of the bull gear.

Sort of a tradeoff. You don't want it too deep or you won't get
as much grip. (Hmm ... do I remember a key in there?)

O.K. According to the manual, there is a Woodruff key both in
the bull gear and in the pickoff gear at the outboard end of the
spindle.

And step (1) of "RE-ASSEMBLING THE HEADSTOCK SPINDLE" says:

"Clean all parts thoroughly, including the bearings,
and lightly file off all burrs from the spindle"

therefore -- not hardened. :-)

Also -- there is a brass plug under the setscrew holding the
preload collar adjustment onto the spindle. (It engages the threads, so
it must have that brass plug to avoid damage to the threads.)

[ ... ]

Note, BTW, that it is old enough so it has a two-pin power plug and a
separate ground wire. This should give some idea of the age. :-)

Mine came without power plug; don't know why.

Mine had a replaced power cord with the modern 3-pin plug, but
note the illustration on the front page of the manual.

[ ... ]

Good. There was only one for this one, based on the manual. It
is a split collet which screws onto the end of the spindle and accepts a
1/8" shank "point".

That's what I have, if memory serves.

O.K. Easier to have one than to make one. :-)

My spindle takes almost no effort to turn. I suspect that I
could breathe on the edge of the larger pulley and move it.

Mine is a bit stiff to turn, which is probably why it heats up. I
haven't figured out why it is so stiff. If I tighten the bearing caps
down until they seat, the spindle is too tight. If I leave them
unscrewed, they walk off. I suspect that a bearing was not pressed
quite home on the spindle shaft.

That is possible. Or a bearing is dying.

I will take the whole thing apart and see. I don't recall any bearing
being hard to turn when I had the caps off. My suspicion is that a
bearing was replaced, and for some reason they didn't or couldn't fully
seat the bearing race on the spindle shaft. With the lathe, I ought to
be able to make a pusher tool.

Yep.

[ ... ]

I'm making a new T-nut and spacer for the Dickson style toolpost that
came with the lathe.

O.K. So make a spare to fit the rod which comes with the
toolpost grinder. (BTW -- the manual says that it is for up to an 11"
lathe, but I feel quite happy with it on my 12" Clausing.)

Close enough, given that I will need to make the spacer. I may already
have the post, attached to a brass plate. The Dumore appears to have
been used on a bench.

Mine was attached to a steel plate, about 1/8" thick IIRC, and
it bent when I tightened up the nut to lock the grinder column onto the
compound.

[ ... ]

I suppose I could ask DuMore. Perhaps some oltdtimer will recall.

Perhaps -- though I think that a few years ago (shortly after I
got the manual for my DuMore Drill grinder) they cleared out the old
manuals -- and perhaps the older employees as well.

Right. I do know that they were polite, but didn't really want to talk
to me about something that old.

They want to forget about them, which is why I feel comfortable
posting the scans of the manuals.

[ ... ]

Right. The 90-degree rotations are to prevent the plates from coming to
a common cylindrical surface, versus a plane. The underlying
mathematical trick is to choose motions that collectively exclude all
but the desired surface. This is the key to origination of specified
shapes.

Hmm ... IIRC, it is a "saddle" surface in which any would mate
with any other in some rotation.

And since you can't rotate the orientation you may wind up with
a negative or positive bow to the taper even with multiple chucks
against one spindle.

Yes, if one goes that far. But for planing dings flat, it should work.

O.K.

[ ... ]

Note that the collet adaptor *is* hardened, even though the
spindle is not. So, you should have minimal dings in the adaptor.

The collet adapter has many dings in it. The lathe was carelessly used
for awhile.

Oops!

For the female 5C taper, I can use a brand new 5C collet of good
manufacture as a reference.

What has happened to the female taper of the adaptor? Given how
hardened they are, I would not expect dings there. Have you checked and
found any? (Granted, mine was acquired new.)

It has some dings there too.

O.K. I would then set up the toolpost grinder and re-grind the
taper there -- *after* fixing the external taper of the adaptor and the
internal taper of the spindle.

[ ... ]

The only solution is to get a taper attachment and make your own.

I have the taper attachment. The trick is setting the
attachment to the degree of precision suggested by the number of digits
after the decimal point in the Morse taper specs. :-)

Five significant digits. I'm sure that Morse hit that all the time.

:-)

They probably set it to a sine bar which might work out to a convenient
gauge size. O.K. 0.62400"/' is 0.05200"/", or 0.26000" for a 5" sine
bar. Actually -- half of that, 0.13000" for half of the taper for
setting a taper attachment. (Start with a test bar in the spindle or
between centers, set the taper attachment to match a sine bar with the
spacer held against it, then lock things down and use the taper
attachment to cut and grind your taper.

Actually, if the female taper in your spindle isn't too worn (versus
dinged), you can indicate the taper and use this to adjust the taper
attachment to exactly match that of the spindle, allowing a light
cleanup grind to eliminate dings et al.

Yes -- but for making a master taper for a different lathe (one
which you don't have to hand) the setting is a bit more tricky. When
cutting a Morse 2 or a Morse 3 on the lathe (with a Morse 4-1/2 in the
spindle), I set up a stop and a test bar, with a digital dial indicator
reading the movement of the carriage. (Someone had installed a mount for
the dial indicator long ago, and before I replaced the leadscrew and nut
with unworn ones.) Zero the indicator with the carriage against the
stop, then move it to clamp a 3" gauge between the carriage and the stop
and check the shift of the cross-slide. Adjust until it is right for
the taper which I want to turn (as close as I could read it with a
0.0001" digital dial indicator). I did this to set up both the 4-1/2
taper Which was backwards from the direction I was cutting) and to set
up the MT-3 and MT-2 bores for the inside of the spindle adaptors prior
to finishing with Morse Taper finish reamers. I have MT-0 through MT-5,
but not MT-4-1/2. 1-5 were in a set I got from eBay in a nice fitted
wooden box. 0 was one which I bought years ago to make tuning pegs for
an Appalachian Dulcimer which I was making. :-) A recent acquisition at a
local metalworking club meeting was a MT-2 roughing reamer.

I've got Morse taper gauges (both male and female) for 1, 2, and
3, and (so far) a female only for MT-4, but nothing for MT-4-1/2. I may
have to actually set up and make that and harden both sides and use the
surface grinder to finish.

BTW I have an interesting sine micrometer. it has a tiny captive
1" sine bar, with a micrometer spindle controlling one end, and
a T-shaped anvil for the other side of the workpiece. Pity it
isn't a full 5" sine bar.

[ ... ]

Ah. This sounds more practical. The crossfeed on the 5914 doesn't seem
long enough for convenient cutting on the back side, especially with
large workpieces.

Unless you have the cross-slide made for turret work, which has
multiple T-slots for mounting alternate toolposts on the back. This is
usually used for mounting a parting tool upside down, so the chips pour
out of the slot instead of potentially jamming.

Ah. I always wondered why upside down helped.

It also helps with a plain bearing lathe in that the wear
normally allows the spindle to lift, and it is pretty much un-worn in
the opposite direction which is where the forces are with an inverted
parting tool coming from the back.

I tried the cutoff tool for the first time yesterday. The blade is
mounted in a Hardinge C31 holder which is in turn clamped in a Dickson
toolholder. The setup does work, but the force caused the entire
toolpost assembly to rotate slowly, causing all manner of problems until
I realized what was happening. I suspect that the crooked T-Nut is
preventing me from tightening things adequately.

I have this problem from time to time on the Compact-5/CNC.

Put some paper between the toolpost and the plate and more
between the plate and the top of the compound. This resists sliding a
bit better than than nicely ground surface on the bottom of the
toolpost. The paper deforms into every tiny imperfection in the
surface, and thus grips better.

The Phase-II clone of the Aloris is not so nicely finished on
the bottom and is better at resisting slipping. I presume that the
genuine Aloris is similar.

I am almost done making the new T-Nut. If this fails to prevent
rotation, I'll need to modify the 3/4" spacer plate to have a shallow
ridge that nests in the cross-feed's T-slot below and accepts the
locator pin from the toolpost above.

Try the paper, first. That may be all that you need. It is
often used to keep workpieces from slipping in milling vises.

Part of the problem is that the blade is far from the center of the
toolpost, giving the cutoff forces considerable leverage to rotate the
toolholder.

Of course.

And I did have chips catching as I tried to cut a 5/8" rod off, and the
rod grabbed and spun in the old 5C collet. No damage done, despite the
drama.

With only a 5/8" rod? perhaps the drawbar was not set tight
enough before locking it against rotation? (IIRC, you do have the lever
style drawbar, don't you?)

But there was no squealing or other drama otherwise, so the setup is
rigid enough, and the lathe strong enough.

Indeed. Now I did hit problems trying to part off some 6"
diameter 12L14. The parting tool was just not strong enough with the
amount of extension needed to reach the center of the workpiece.

Of course, it also allows a rear-mounted parting tool to work
without having to run the spindle in reverse.

Yes. And given that the 5814 is reversible, this sounds like the ticket.

A problem with the original spindle, since that was a 2-1/4x8
threaded spindle. However, I did change it out for a L-00 which does
not have that problem.

It's also a reason to buy a cutoff blade holder that is useable with
reverse rotation.

Yep. But you don't need reverse with a back-mounted parting
tool.

I also wondered what was different about a cross-slide meant for turret
work.

That is it. Typically the parting tool is kept on the rear
toolpost, and some other tool (perhaps a bevel tool or whatever is
needed -- perhaps multiple ones in a turret toolpost -- kept on the
front toolpost. (For a large enough production run, a turret style
toolpost can be worth the time to set it up. In the meanwhile, the bed
turret can carry an amazing array of tools doing things which you would
normally do with the normal toolpost. You can even have it turning two
diameter steps on the workpiece at the same time with the right tools.

Sounds worthwhile in production, but a pain to get set up correctly.

Exactly. I haven't ever set up the compound tooling (turning to
two diameters in a single pass), but I have set up the bed turret with
all six stations in service, and with one serving double -- both as a
stop for setting workpiece rod stock extension, and as a centerdrill
(which extends out of the center of the stop). I don't have the ability
to extend the workpiece with it still rotating, so I did not need to
make the stop a bearing mounted one. :-) The stations were as follows:

1) Stop/center drill

2) tap drill

3) releasing tap holder

4) OD knurling tool (T-shaped, with rolls coming in from opposite
sides)

5) turn to diameter in a single pass (roller box tool -- turning
tool with built-in steady rest.)

6) Geometric die head, to thread reduced part of workpiece.

In the meanwhile, I am also using the cross slide to cut a
runout groove (because the threads are not full depth to the
face, and the things which it mates need to screw up to the
face) and to part the workpiece off. While it is parting off, I
am using a file to bevel the end, and both sides of the
remaining knurled full OD.

Next time I set up, I'm going to try two changes:

3) Form tap instead of gun tap in the holder. No chips, so
I don't need to tap drill as deeply, and can do a fresh start of
the center hole for each piece. As it was, after about six or
eight pieces, the hole would walk far enough off center to need
to cut off an undrilled inch of waste stock to let me re-start
the center drilling.

4) Cut style knurling tool -- looks like a 3-jaw chuck but with
the angled cut style knurling cutters. Should produce sharper
knurling.

Setup. I recently fitted my Millrite MVI vertical mill with X and Y
DROs (Jenix). What a difference that makes. Before, I was having
endless trouble hitting a dimension because of the large backlash of an
aged machine. Now, I am hitting things to within 0.001" or so. I will
soon add the quill Z axis. (I have the scale for the table Z. but it
will be a pain to fit it, and the quill is turning out to be the more
immediate need.)

Some of these days I'll get around to mounting the Shooting Star
DRO on my Clausing lathe. I've had it for a few years now, but never
taken the time to do it right.

Enjoy,
DoN.

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