What kind of lathe? What kind of spindle nose?

A faceplate held in the lathe chuck would be marginally useful IMO.

You can in general get *anything* for any normal lathe, whether it has a
threaded spindle nose, a D-n spindle nose, or an L-n spindle nose. Just look on
ebay.

Lathe dogs are excellent to buy imported. They are low precision items.

Buy a copy of "How To Run A Lathe" by the South Bend Lathe Works. Read it
several times. That book is a gem. Any edition is fine. Lindsay reprints it but
there are bazillions floating around used. I bet I own 4 of 'em.

GWE

xray wrote:

So I recently got myself a used matal lathe. It came with a pretty good
selection of accessories, but I am looking to fill what I don't have
that I may need.

First, I have almost no experience, so I have been studying. I have
several books including MH and "Machine Shop Practice." To firm this
stuff in my brain, I ordered the 5-DVD set from
http://technicalvideorental.com/rental_12.html

"Lathe Learnin'" made by Precision Measurement in San Antonio. Good
Stuff. I learned a lot that willl save me much wasted time.

In two sections near the end, he uses a faceplate that, rather than
being on the lathe spindle has its own spindle that is then clamped in
the lathe chuck. At one point the spindle has a point as it is used to
drive a dog for taper turning. Later, what appears to be the same
faceplate, is used to set up a piece clamped off of the lathe for
drilling and boring. I couldn't tell, but it seems that the center point
would be in the way for this operation. No mention was made either time
about the face plate and spindle itself.

So -- this seems useful -- the question: Are others doing this? Can I
easily buy a faceplate/spindle that I can clamp in my chuck.
With/without a center point? If so what do I look for and where to find
it.

----

Right now I've got nothing I can use on the headstock end for turning
between centers. The above questions offer one option that may be the
most flexible for my needs. I could order a big MT-5 center to fit my
spindle but the video made me think.

I have no dogs. Suppose I may encounter a need to turn something between
.5 inch and 2.5 inch. How many steps of dog capacity do I need? Is there
a rule of thumb? Is there a more flexible way of providing the drive
force?

Thanks in advance.

In article ,
xray wrote:
On Mon, 18 Jul 2005 18:58:30 -0700, Grant Erwin
wrote:

What kind of lathe? What kind of spindle nose?

Well, mine has a 2 1/4 x 8 TPI threaded spindle with an internal
(appears to be) MT 5 taper.

A faceplate held in the lathe chuck would be marginally useful IMO.

Why? It would not have occurred to me, but after seeing it in the video,
it seems like a reasonable idea with some real advantages (and maybe a
few disadvantages.)

Its advantage is that you can move a project between the lathe,
milling machine, and drill press. But, you can do the same with an
adaptor machined to duplicate the lathe spindle nose on a rotary table
on the milling machine or clamped to the drill press.

And -- if you can't easily find a faceplate for your lathe's
spindle, you could use it there -- with the disadvantage that the
faceplate may be more off center (in a 3-jaw chuck), or may require
tweaking (in a 4-jaw chuck), -- *plus* -- that moving the faceplate a
greater distance from the spindle nose increases the likelihood of
chatter.

[ ... ]

Lathe dogs are excellent to buy imported. They are low precision items.


You didn't answer my question about how many are needed to cover a range
of diamerters. Maybe it's a stupid question, but I don't know the
answer.

Neither did I. I didn't because different sets of lathe dogs
need different numbers to cover a given range. So -- start out with
*whose* lathe dog sets -- and the answer will be in front of you in
their catalog.

If you buy them used from eBay auctions, you will likely get
them one or two at a time. Beware that the tails of some may be too
thick to fit the slot of the dog driving plate for your lathe, so you
may have to grind down the thickness of the tail, or widen the slot.

Fork-tail dogs or straight-tail dogs are used with plain
faceplates, where a screw is fed through one of the slots in the
faceplate, and secured to the tail of the dog (if a straight tail dog),
or passed between the tails (with a fork-tail dog).

There are all kinds of designs. Straight-tail, bent-tail,
forked-tail. The older ones have a longer square-headed screw, which
has been superseeded by shorter slotted headless screws, because the
square heads are more likely to catch in a sleeve, and pull you into the
running machine. The slotted headless screws are shorter, so they cover
a smaller range, needing more to cover the whole of your range.

There are also bar-type dogs, which consist of two parallel
bars, joined by two square-headed screws, and a bent tail from one of
the two bars. One of the two bars will have a 'v' at the center, and
this will cover a much larger range (given long enough screws. But it
is normally used on a dividing head for turning a mandrel for something
like slotting the teeth in a gear.

To go with that, I've seen centers which had a T-bar at the
pointed end, with slots in the ends to steady the tail of such a dog as
in the paragraph above. The slots each had a screw to clamp the tail
into a fixed position. (Sometimes, lathe dogs were tied in place with
wet rawhide, which would then shrink as it dried, holding the workpiece
firmly against chatter.)

I've seen ones which were obviously made for a single diameter
workpiece, with two U-shaped slots on the ends for screws to attach it
to the faceplate. Those have a very short setscrew.

So -- I hope that you at least now understand why you aren't
getting a fixed number for the size range which you specified.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Mounting a face plate on a spindle in the chuck is, for the beginner,
a questionable procedure. The whole idea of turning between centres is
accuracy. Lathe chucks tend to have less than optimal accuracy when
requiring tight tolerances. Also, by moving the "centre" or point as
you referred to it, farther from the bearings in the head, you tend to
decrease rigidity in your setup. By using a spindle mounted faceplate
and a soft point MT5 (if that is what your spindle is) centre to do
you "between centres turning" you will have a setup on which you will
be able to produce the most accurate work your lathe is capable of
producing.
Buy the largest faceplate your lathe can swing, and a small dog drive
with a couple of drive dogs.

Are you sure your spindle bore has a MT5 taper?

"xray" wrote in message
...
|
| So I recently got myself a used matal lathe. It came with a pretty
good
| selection of accessories, but I am looking to fill what I don't have
| that I may need.
|
| First, I have almost no experience, so I have been studying. I have
| several books including MH and "Machine Shop Practice." To firm this
| stuff in my brain, I ordered the 5-DVD set from
| http://technicalvideorental.com/rental_12.html
|
| "Lathe Learnin'" made by Precision Measurement in San Antonio. Good
| Stuff. I learned a lot that willl save me much wasted time.
|
| In two sections near the end, he uses a faceplate that, rather than
| being on the lathe spindle has its own spindle that is then clamped
in
| the lathe chuck. At one point the spindle has a point as it is used
to
| drive a dog for taper turning. Later, what appears to be the same
| faceplate, is used to set up a piece clamped off of the lathe for
| drilling and boring. I couldn't tell, but it seems that the center
point
| would be in the way for this operation. No mention was made either
time
| about the face plate and spindle itself.
|
| So -- this seems useful -- the question: Are others doing this? Can
I
| easily buy a faceplate/spindle that I can clamp in my chuck.
| With/without a center point? If so what do I look for and where to
find
| it.
|
| ----
|
| Right now I've got nothing I can use on the headstock end for
turning
| between centers. The above questions offer one option that may be
the
| most flexible for my needs. I could order a big MT-5 center to fit
my
| spindle but the video made me think.
|
| I have no dogs. Suppose I may encounter a need to turn something
between
| .5 inch and 2.5 inch. How many steps of dog capacity do I need? Is
there
| a rule of thumb? Is there a more flexible way of providing the drive
| force?
|
| Thanks in advance.
|

"xray" wrote in message
...
On Tue, 19 Jul 2005 00:41:01 -0400, "Mungo Bulge"
wrote:

Are you sure your spindle bore has a MT5 taper?

Not absolutely, but pretty sure.

I have a document for a similar lathe, but I see that it doesn't match
mine exactly. One option in those pages shows MT 5 for the spindle. My
measurements seem to agree with MT 5 pretty close, so I think it is
correct.

To be sure, I guess I should buy an MT 5 center and try it.

No, don't do that. There are spindle adapters that permit the use of
smaller centers, which should be your objective. Look for a #5/#3 adapter,
and use a #3 center, or one the same size as the tailstock center, if it's
different.

What size is your lathe?

Harold

xray wrote:

I have a document for a similar lathe, but I see that it doesn't match
mine exactly. One option in those pages shows MT 5 for the spindle. My
measurements seem to agree with MT 5 pretty close, so I think it is
correct.

To be sure, I guess I should buy an MT 5 center and try it.

I did that when I had a bigger lathe. I believe I still have a No. 5 lathe
center, NOS NIB. Email me offline if you're interested in it -- to email me, see
http://www.tinyisland.com/email.html, thanks.

GWE

"xray" wrote in message
...
On Tue, 19 Jul 2005 00:52:43 -0700, "Harold and Susan Vordos"
wrote:


"xray" wrote in message
.. .

To be sure, I guess I should buy an MT 5 center and try it.

No, don't do that. There are spindle adapters that permit the use of
smaller centers, which should be your objective. Look for a #5/#3
adapter,
and use a #3 center, or one the same size as the tailstock center, if
it's
different.

What size is your lathe?

It has a 13" swing. But this is digressing from my original question
about a separate piece of tooling.

I'm happy to hear about these suggestions/questions but I think I'd
rather hear about how to make or buy an adapter as I described.

Well and good, but is that in your best interest? Wouldn't you prefer to
learn things that are useful instead of things that may not be?

I worked as a machinist for 26 years of my life, including running my own
business for 16 of those years, and never encountered any such a setup.
Frankly, I wouldn't be too interested in one, either. If for no other
reason, on small machines, the more you add to length, the greater are your
machining problems. There are other methods to improve holding
capabilities, most of which would be more useful. Soft jaws is a good place
to start your learning curve, but reserve that for the time when you better
understand cutting tools and how to apply them. At this point, you're
worrying about things that may never be an issue when you are more familiar
with machining techniques.

Regards holding objects between centers, it's easy enough to chuck a short
length of stock and turn a 60 degree center if you'd like to avoid buying a
headstock center, which you'll find gets very little (if any) use when you
get better at machining. Working between centers is precise, but a complete
PITA as compared to holding your work by other methods (speaking of soft
jaws).


The spindle adapters are something that I might should learn about too.

The more I learn on this stuff, the more I find I have to learn.

We have no idea what you do for a living, but if you think you can master
machining in a few days, you're likely to be very unhappy. It takes most
guys that work in the trade several months to become even remotely
competent, assuming they're doing work of any quality. Anyone can make
chips, but it takes skill, talent and considerable experience for one to
make parts per print, reliably, and with reasonable speed. You'll come to
respect the talent of others as you struggle with what you may think are
simple procedures.

You're right about the more you have to learn. Few, if any, machinists
that have worked in the trade for a lifetime are well rounded enough to be
comfortable in all machining processes. There's just too much to know to
learn it all. You could easily spend a lifetime on gear cutting alone.
Don't let that bother you-----simply learn to do the things that are
important to you.

Harold