In article ,
"DoN. Nichols" wrote:

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

On 2008-02-01, Joseph Gwinn wrote:

[ ... ]

The ring? Now it makes sense. Not that I want to replace or take the
headstock apart just yet.

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".


Are you *sure* that it is hardened? I know that the taper in
the tailstock yields to a No. 3 Morse Taper reamer to clean it up, as I
have done so.

Hmm. No, I have not tested it. But I'd bet that it is hardened, given
its manufacture and age. That isn't to say that the spindle will be
glass hard. It's probably hardened for some optimum combination of
toughness and resistance to surface damage. Like dings.

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.

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


I [Joe] don't yet have a toolpost grinder.

Well, actually I do, a partial kit inherited from my maternal
grandfather. It's a Dumore model 11G, and is too old for Dumore to have
parts.

Do you have a manual? I do, in PDF format. Mine is a "Series 11"
model 8119.

I don't know the model number - the block on the tag is blank.

Same on mine, FWIW.

I'd be interested in a copy of your Model 11 manual. The email above is
real, but this would be a nice addition to the dropbox (if it isn't
already there). Thanks.

Try going to:

http://www.d-and-d.com/misc/MANUALS/DuMore/DuMore_Series-11_TP_Grinder_Manual.pdf

Got it. Thanks.


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.


Do you have the collet for the end of the spindle for the
internal stones? I had to make one of my own.

It came with at least one collet.

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.


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.


I did make (aside from the collet) a new T-nut to fit the
Clausing toolpost.

While I was about it, I also made a collar to speed setting the
grinder at the proper height above the compound. It is stored in the
box with the grinder, of course.

I've just noticed that it is suggested in the manual. :-)

I'll also have to do this too.

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.


Alternately,
does anyone know the name of the inventor, perhaps also a founder of
Dumore?

I think that the DuMore company has been around a lot longer than
my Series 11 grinder at least -- and *it* is too old to get manuals or
parts from DuMore.

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.


Note that with the surface plates, you are also expected to
rotate them 90 degrees from time to time during the process. The
orientation here is fixed by the design, so you could wind up with a
concavity or convexity to the spindle nose which would be fine with all
of the mating parts which you have made -- but which would not work
properly with any new acquisitions, requiring you to start the lapping
process from the beginning with each new acquisition. I would not do it
this way.

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.

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.


In the present situation, the pieces are already almost in conformance,
and the theory or hope is that the dings will be preferentially ground
off first.

I would go for a known good reference, and scrape everything to
fit it. This would require finding a MT-4-1/2 gauge pair. I have yet
to see those on eBay -- or I would already have them. :-)

I think I'll do hi-spot blue and a hand stone to de-ding the spindle
female taper and the mating collet holder male taper, rotating the
collet in the spindle so the dings cannot nest.

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.


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.


If the MT-5 taper were the same as the MT-4-1/2, then you could
probably get away with the trick. But a MT-7 is just too big. The
taper alone is 10" long. :-) Frankly, I don't think that I would want to
have to lift a MT-7 gauge -- male or female. I think that the female
would be something like 6" diameter, and add to that the 10" length, and
even with the tapered hole, it would weigh a lot. The weight of the
male gauge would be similar, when you take into account the length and
diameter of the knurled handle.

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.

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.


Having the clutch kickout sounds like a really nice feature.

Especially during early education exercises.

:-)

By the time we get to about 20 TPI, I can do it at more
reasonable speeds.

But you can cut away from the headstock by mounting the
threading tool upside down -- you don't need to put it in back.

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.

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 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.

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.

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.

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


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.

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


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.


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.)


Joe Gwinn