Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 124
Default Which tool is needed. . . ?

If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL
  #2   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 147
Default Which tool is needed. . . ?

TwoGuns wrote:
A metal lathe a metal mill
or some other?

DL


It's hard to hold a job in the rotating spindle of a mill, but
relatively easy to mount a job on the saddle of a lathe, so lathe trumps
mill. In fact, a mill is a lathe, specialised for work with stationery
job and rotating cutter.

Jordan
  #3   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 4,562
Default Which tool is needed. . . ?

TwoGuns wrote:

If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL



Lathe. I've tried using a mill as a substitute before.

Wes
  #4   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 954
Default Which tool is needed. . . ?

On Nov 22, 3:36*pm, TwoGuns wrote:
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL


If you want to see how flexible a lathe can be, go look at back issues
of The Model Engineer. They had virtually nothing in the way of
modern machiine tools and came up with a lot of ways of doing with
what they had.

Stan
  #5   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,502
Default Which tool is needed. . . ?

On Sun, 22 Nov 2009 12:36:22 -0800 (PST), TwoGuns
wrote:

If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL



A mill.


"Aren't cats Libertarian? They just want to be left alone.
I think our dog is a Democrat, as he is always looking for a handout"
Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls.
Keyton


  #6   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,705
Default Which tool is needed. . . ?

TwoGuns wrote:
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL


A good lathe.
It can be used for far more things than a mill.

--
Steve W.
  #7   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 22, 3:36*pm, TwoGuns wrote:
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL


A horizontal boring machine with a spindle that accepts lathe chucks.

jsw
  #8   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 621
Default Which tool is needed. . . ?


"TwoGuns" wrote in message
...
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?


FWIW even at my level I seem to use a small lathe about 8 times as often as
a small mill.

On a Desert Island I would have a lathe, The Godfather DVD and Dylan's
Highway 61 revisited...

--
Michael Koblic
Campbell River, BC


  #9   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 230
Default Which tool is needed. . . ?


"TwoGuns" wrote in message
...
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL


A lathe can make another lathe, but a mill can not make another mill. No
CNC's allowed.


  #10   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 23, 4:58*am, "Rick Samuel"
wrote:
"TwoGuns" wrote in message
...
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?


DL


*A lathe can make another lathe, but a mill can not make another mill. *No
CNC's allowed.


A lathe can make shafts, bearings and threads but a mill is much
better for machining ways, dovetails, etc. I've tried, it wasn't fun.

I picked the horizontal boring machine because it combines elements of
both, the spindle and tailstock of a lathe plus the XYZ axes of a
mill. If for some strange artificial reason I had to build one machine
to do everything it would resemble a horizontal boring mill with a
leadscrew added for threading, but it wouldn't be nearly as easy to
set up as separate turning and milling machines.

jsw


  #11   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,224
Default Which tool is needed. . . ?

On Mon, 23 Nov 2009 03:57:55 -0800 (PST), Jim Wilkins
wrote:

On Nov 23, 4:58*am, "Rick Samuel"
wrote:
"TwoGuns" wrote in message
...
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?


DL


*A lathe can make another lathe, but a mill can not make another mill. *No
CNC's allowed.


A lathe can make shafts, bearings and threads but a mill is much
better for machining ways, dovetails, etc. I've tried, it wasn't fun.

I picked the horizontal boring machine because it combines elements of
both, the spindle and tailstock of a lathe plus the XYZ axes of a
mill. If for some strange artificial reason I had to build one machine
to do everything it would resemble a horizontal boring mill with a
leadscrew added for threading, but it wouldn't be nearly as easy to
set up as separate turning and milling machines.

jsw

Some years back, I got playing around with me SB "A" and some CI
plate. After making a milling attachment, I made a duplicator for my
wood lathe, one piece of which is a piece with 14 flat sides.
Gerry :-)}
London, Canada
  #12   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 23, 6:05*pm, Gerald Miller wrote:
On Mon, 23 Nov 2009 03:57:55 -0800 (PST), Jim Wilkins
...

Some years back, I got playing around with me SB "A" and some CI
plate. After making a milling attachment, I made a duplicator for my
wood lathe, one piece of which is a piece with 14 flat sides.
Gerry :-)}
London, Canada-


I made a lathe milling attachment, and then found a South Bend one.
Both work about equally poorly unless I take VERY light cuts. The
problem seems to be the inadequate clamps that hold the carriage down.

How did you index the 14 sided piece? A 14/28/56 tooth change gear?

jsw
  #13   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,224
Default Which tool is needed. . . ?

On Mon, 23 Nov 2009 15:55:42 -0800 (PST), Jim Wilkins
wrote:

On Nov 23, 6:05*pm, Gerald Miller wrote:
On Mon, 23 Nov 2009 03:57:55 -0800 (PST), Jim Wilkins
...

Some years back, I got playing around with me SB "A" and some CI
plate. After making a milling attachment, I made a duplicator for my
wood lathe, one piece of which is a piece with 14 flat sides.
Gerry :-)}
London, Canada-


I made a lathe milling attachment, and then found a South Bend one.
Both work about equally poorly unless I take VERY light cuts. The
problem seems to be the inadequate clamps that hold the carriage down.

How did you index the 14 sided piece? A 14/28/56 tooth change gear?

jsw

It is a flat rectangle (6 surfaces) with two corners cut off to give
two more surfaces, then the perimeter is chamfered.
Top, bottom, six vertical faces and six bevels = 14
I clamped the piece to the milling attachment and used a fly cutter on
the spindle.
Gerry :-)}
London, Canada
  #14   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,475
Default Which tool is needed. . . ?


"Rick Samuel" wrote in message
...

"TwoGuns" wrote in message
...
If you could only use one machine tool to make ALL or ANY machine
tools you want what tool would you choose? A metal lathe a metal mill
or some other?

DL


A lathe can make another lathe, but a mill can not make another mill. No
CNC's allowed.


What part of a mill can't a mill make? How do you machine a lathe bed in a
lathe?

I think I'd prefer to use a mill to make 90% of either a lathe or a mill.
And for the other 10% I think it would be easier to make a spindle on a mill
than it would be to mill a cross slide table, but then again I've never seen
a very nice milling setup in a lathe.

RogerN


  #15   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 1:24*am, "RogerN" wrote:

A lathe can make another lathe, but a mill can not make another mill. *No
CNC's allowed.


What part of a mill can't a mill make? *How do you machine a lathe bed in a
lathe?


I think the idea is to remove the head and tailstock and use a tool
bit in the carriage to plane the ways. You might want to hang the new
lathe bed upside down over the old one so you can plane all the way
surfaces parallel.

When I needed to remachine a worn lathe bed I used a large horizontal
milling machine.

I think I'd prefer to use a mill to make 90% of either a lathe or a mill.
And for the other 10% I think it would be easier to make a spindle on a mill
than it would be to mill a cross slide table, but then again I've never seen
a very nice milling setup in a lathe.

RogerN


You can mill cylindrical or conical surfaces on a rotary table or
between indexer centers. That's how I make tubing bender dies. I
suppose you could cut threads with a vee cutter or a fixed flycutter
bit by gearing the indexer to the table feed.

The American Precision Museum in Vermont has machine tools going back
to 1820 or so. By about 1860 practical experience had shaped them into
the forms we still have now. The smaller details such as quick-change
gearboxes and HSS tool bits were in place by 1900.

There are some versatile hybrids meant for moderate production runs
such as the Lincoln miller, which would be my model for a machine that
makes other machines.
http://www.sperdvac.org/Horizontal%2...ne_lincoln.jpg

I would make the tailstock support with two posts like the headstock
to better support it for tailstock drilling.

Scroll down to the bottom and look at "take-up" bearings:
http://www.baileynet.com/index.php?i...tegory=1000011

jsw


  #16   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 1:24 am, "RogerN" wrote:

A lathe can make another lathe, but a mill can not make another mill. No
CNC's allowed.


What part of a mill can't a mill make? How do you machine a lathe bed in a
lathe?


I think the idea is to remove the head and tailstock and use a tool
bit in the carriage to plane the ways. You might want to hang the new
lathe bed upside down over the old one so you can plane all the way
surfaces parallel.

When I needed to remachine a worn lathe bed I used a large horizontal
milling machine.


I recall some drawings that I saw in the '70s, at _American Machinist_, that
illustrated the self-replicating nature of the lathe. It was a hypothetical
machine, with many components machined flat and/or bored on the faceplate
and with cylindrical ways, like a chucker (American Lathe?) that gained some
interest around 1978 - 1980 or so. There also were very small lathes,
typically types of specialized screw machines, made that way in the early
part of the last century.

Some of the very earliest screw-cutting lathes, maybe even Maudslay's
machine, had a V-way in front and a flat bedway in the back. The idea behind
that was that the V-way didn't require perfect straightness; slight
compensations could be made by filing or scraping the flat way to
compensate, effectively tilting the cross slide up or down a bit. It always
seemed to me that this would help only at one diameter of work, but that's
the way it was done, and many of them were made by hand before planers were
in common use for the purpose. The idea of the self-replicating lathe may
have included an assumption that some of the work was done by hand.

In any case, the running parts of a lathe depend upon round journals and
bushings, and most parts can be made that way either for running or for
locating, so the lathe was the most capable of self-replication.

--
Ed Huntress


  #17   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 10:10*am, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
Some of the very earliest screw-cutting lathes, maybe even Maudslay's
machine, had a V-way in front and a flat bedway in the back. The idea behind
that was that the V-way didn't require perfect straightness; slight
compensations could be made by filing or scraping the flat way to
compensate, effectively tilting the cross slide up or down a bit.


Are you sure? One vee way constrains its side of the carriage
horizontally and vertically, the other flat way allows the carriage to
center itself on the vee without over-constraining it. My South Bend
has two inverted vees for the carriage, which will wear out any slight
spacing error, and a vee plus a flat for the head and tailstocks which
won't.

.... The idea of the self-replicating lathe may
have included an assumption that some of the work was done by hand.
Ed Huntress


What I've read in Holtzapffel et al suggests that the old lathe bed
was largely a reference for checking the new one as it was filed,
scraped and fitted by hand.

jsw
  #18   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 10:10 am, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
Some of the very earliest screw-cutting lathes, maybe even Maudslay's
machine, had a V-way in front and a flat bedway in the back. The idea
behind
that was that the V-way didn't require perfect straightness; slight
compensations could be made by filing or scraping the flat way to
compensate, effectively tilting the cross slide up or down a bit.


Are you sure?


I'm sure that's the way many lathes were built, prior to the mid- or late
1800s. I'm not sure that the people explaining it got their explanation
right. I've always questioned it, but I never had a lot of literature to go
on.

One vee way constrains its side of the carriage
horizontally and vertically, the other flat way allows the carriage to
center itself on the vee without over-constraining it.


Well, that's true, and the V-and-flat configuration has been used for the
simple reason that it requires little coordination between the location of
the two ways. That was always the way that I thought it was intended, from
the start. But a couple of sources that I used back when I was working on
the _AM_ 100th Anniversary Issue (1977) discussed the use of the flat way to
compensate for inaccuracies in the V-way.

It may be that one was just quoting the other unquestioningly. I suspect
that's the case, but I have no basis to question it except my own suspicion.

My South Bend
has two inverted vees for the carriage, which will wear out any slight
spacing error, and a vee plus a flat for the head and tailstocks which
won't.


Yeah. My South Bend, too. g

.... The idea of the self-replicating lathe may
have included an assumption that some of the work was done by hand.
Ed Huntress


What I've read in Holtzapffel et al suggests that the old lathe bed
was largely a reference for checking the new one as it was filed,
scraped and fitted by hand.


'Could be. I haven't read anything about it for decades, and there's been
quite a bit written about Maudslay's screw-cutting lathe. The trouble with
these informal histories is that they tend to use each other as sources,
which perpetuates a lot of wrong ideas.

--
Ed Huntress


  #19   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 11:00*am, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
......
'Could be. I haven't read anything about it for decades, and there's been
quite a bit written about Maudslay's screw-cutting lathe. The trouble with
these informal histories is that they tend to use each other as sources,
which perpetuates a lot of wrong ideas.

Ed Huntress


I just checked my two best sources, Holtzapffel #2 and Oscar Perrigo's
1916 "Lathe Design", Both skip quickly over the rationale for the
choice of flat vs vee lathe ways, and suggest that ease of production
was as much or more of a factor as sustained accuracy.

jsw
  #20   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 11:00 am, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
......
'Could be. I haven't read anything about it for decades, and there's been
quite a bit written about Maudslay's screw-cutting lathe. The trouble with
these informal histories is that they tend to use each other as sources,
which perpetuates a lot of wrong ideas.

Ed Huntress


I just checked my two best sources, Holtzapffel #2 and Oscar Perrigo's
1916 "Lathe Design", Both skip quickly over the rationale for the
choice of flat vs vee lathe ways, and suggest that ease of production
was as much or more of a factor as sustained accuracy.

jsw


Well, yeah, we know that's why it was done later, after planers came into
widespread use. It's a lot easier to make three planes work together than
four.

And that may be (and I agree with your conclusion; it probably is) the
reason it was done from the very beginning.

As I think about this, I'm remembering what I thought about it at the time,
30 years ago. I believed then that the issue was the difficulty, without
planers, mills, or big surface grinders, of getting the four planes of a
pair of V-ways coordinated for straight and smooth travel. One way to
interpret this is that you can adjust the single plane of the flat way a lot
easier than the pair of planes you have with a second V. So to say that it
was simpler to correct accuracy with the V-and-flat could just mean that; if
the ways are hand-finished, you're correcting accuracy, and V-and-flat is a
lot easier to correct than two V's.

Maybe. g

--
Ed Huntress




  #21   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 1:04*pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
I just checked my two best sources, Holtzapffel #2 and Oscar Perrigo's
1916 "Lathe Design", ...

...
As I think about this, I'm remembering what I thought about it at the time,
30 years ago. I believed then that the issue was the difficulty, without
planers, mills, or big surface grinders, of getting the four planes of a
pair of V-ways coordinated for straight and smooth travel. One way to
interpret this is that you can adjust the single plane of the flat way a lot
easier than the pair of planes you have with a second V. So to say that it
was simpler to correct accuracy with the V-and-flat could just mean that; if
the ways are hand-finished, you're correcting accuracy, and V-and-flat is a
lot easier to correct than two V's.

Maybe. g

--
Ed Huntress


If I read Holtzapffel correctly the two sides of inverted vee ways
were at first made separately, joined and aligned afterwards to fit
the fixed and moving poppit heads (headstock and tailstock to us).

"This slight width of base does not afford sufficient lateral support
to the heads, which with only moderate force in turning are liable to
vibration; while exact parallelism of the two angular edged bars is
also necessary. Improvement in stability was sought by making one side
of the bearers flat and broad, fig. 72, with a corresponding flat on
the underside of the lathe heads; retaining one angular side, to give
the direction or common axis. This arrangement also facilitated the
construction, as the parallelism of the two bars was no longer
essential,..."

Fig 72 shows one flat and one inverted vee way on a cast iron bed.

The difficulties of the early machine builders that Holtzapffel
recorded aren't that much different from those of a homebrew machine
tool maker today, except that we can buy ground drill rod and flat
stock and they could hire cheap child labor for tedious hand fitting.

jsw
  #22   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 1:04 pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
I just checked my two best sources, Holtzapffel #2 and Oscar Perrigo's
1916 "Lathe Design", ...

...
As I think about this, I'm remembering what I thought about it at the
time,
30 years ago. I believed then that the issue was the difficulty, without
planers, mills, or big surface grinders, of getting the four planes of a
pair of V-ways coordinated for straight and smooth travel. One way to
interpret this is that you can adjust the single plane of the flat way a
lot
easier than the pair of planes you have with a second V. So to say that it
was simpler to correct accuracy with the V-and-flat could just mean that;
if
the ways are hand-finished, you're correcting accuracy, and V-and-flat is
a
lot easier to correct than two V's.

Maybe. g

--
Ed Huntress


If I read Holtzapffel correctly the two sides of inverted vee ways
were at first made separately, joined and aligned afterwards to fit
the fixed and moving poppit heads (headstock and tailstock to us).


Yeah. In the very beginning of modern lathes, the V-and-flat combinations
were assembled the same way. The first screw-cutting lathes had wood beds
with bolted-on iron ways, IIRC. (I'm doing this from memory; don't bite me.
g)

"This slight width of base does not afford sufficient lateral support
to the heads, which with only moderate force in turning are liable to
vibration; while exact parallelism of the two angular edged bars is
also necessary. Improvement in stability was sought by making one side
of the bearers flat and broad, fig. 72, with a corresponding flat on
the underside of the lathe heads; retaining one angular side, to give
the direction or common axis. This arrangement also facilitated the
construction, as the parallelism of the two bars was no longer
essential,..."


Right. That sounds familiar.


Fig 72 shows one flat and one inverted vee way on a cast iron bed.

The difficulties of the early machine builders that Holtzapffel
recorded aren't that much different from those of a homebrew machine
tool maker today, except that we can buy ground drill rod and flat
stock and they could hire cheap child labor for tedious hand fitting.


Right. Maybe you've peeked at my ideas for a ferrocement lathe with steel
ways. d8-)

(Having finished reading Naaman's _Ferrocement & Laminated Cementitious
Composites_, I'm less enthusiastic about that construction.)

--
Ed Huntress


  #23   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 2:03*pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...

Right. Maybe you've peeked at my ideas for a ferrocement lathe with steel
ways. d8-)

(Having finished reading Naaman's _Ferrocement & Laminated Cementitious
Composites_, I'm less enthusiastic about that construction.)
Ed Huntress-


Too late. There's one from ~1830? at the American Precision Museum
with wrought iron ways mortared into grooves in a granite base.

Another possibility is to make the ways rigid but not precise, like
spacers blocks between two channel irons, and use a bolt-on X-Y table
to control the tool. I would make the head and tailstock spindles a
standard drill rod size and use a separate piece of it to align the
head, tail and X-Y table axes after moving them.

jsw
  #24   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 2:03 pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...

Right. Maybe you've peeked at my ideas for a ferrocement lathe with steel
ways. d8-)

(Having finished reading Naaman's _Ferrocement & Laminated Cementitious
Composites_, I'm less enthusiastic about that construction.)
Ed Huntress-


Too late. There's one from ~1830? at the American Precision Museum
with wrought iron ways mortared into grooves in a granite base.


g Yes, there have been lots of concrete lathes, and stone-base lathes. I
ran a photo of one cast in reinforced concrete in _AM_ around 1978, made in
the USSR, that had a 65-foot-long bed.

My never-ending project is about a lathe for hobbyists. My original idea was
post-tensioned concrete. I may go back to that, based on some things I
learned about ferrocement. Or I may stick with the ferro and change a few
things to deal with issues. Post-tensioned concrete has its own issues.
Neither ferro nor post-tensioned answers all of the problems.

Another possibility is to make the ways rigid but not precise, like
spacers blocks between two channel irons, and use a bolt-on X-Y table
to control the tool. I would make the head and tailstock spindles a
standard drill rod size and use a separate piece of it to align the
head, tail and X-Y table axes after moving them.


Good ideas. Lining things up is one of the issues, of course. Finish-honing
the headstock bearing retainers, using a simplified honing head (closer to a
lapping tool, actually) that runs on the lathe bedways, is a design I worked
on in the early '80s. I still think it would work OK.

--
Ed Huntress


  #25   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 2:50*pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
....

Good ideas. Lining things up is one of the issues, of course. Finish-honing
the headstock bearing retainers, using a simplified honing head (closer to a
lapping tool, actually) that runs on the lathe bedways, is a design I worked
on in the early '80s. I still think it would work OK.

--
Ed Huntress


I would try pillow blocks with setscrews or shaft clamps and jam two
of them together to get preloaded angular contact at the working end
of the spindle. Then the spindle (key-slotted shafting) could be
easily swapped so you could weld a plate on one to mount a chuck, for
instance.

jsw


  #26   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,502
Default Which tool is needed. . . ?

On Tue, 24 Nov 2009 22:46:10 +0000, Mark Rand
wrote:

(Hardinge Dovetail excepted, that works)



Indeed it does...and its actually 3 surfaces..or 5 if you are counting


Gunner
  #27   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 8:38*pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message

...
On Nov 24, 6:42 pm, "Ed Huntress" wrote:





"Jim Wilkins" wrote in message


Interesting, but I think you'd have growth problems at the back end,
unless
you made the spindle float in the inner race of the backside bearing -- or
had the backside bearings run right on the spindle, with clearance.


I'd use a tubular bearing holder (a piece of pipe) cast into a ferrocement
headstock, with floating rollers at the tail end and a pair of facing
tapered roller bearings on the head end. That's one traditional setup for
lathes, and it combines Z-axis stability, high load capacity, and
free-floating at the tail end to deal with Z-axis growth of the spindle..


I'd have to look at what kinds of bearings are cheaply available first.
Ed Huntress-
So you have the drive pulley on the end of the spindle instead of
between the bearings?


Yeah, I worked that out in one of my first sketches, and I saw no real
disadvantage. I was thinking about a pretty large (2 inch) hollow spindle..
In my original version, I didn't even have a drive or gears for threading..
It was going to use thread follower attachments, like the ones used on an
old Unimat or some screw machines.

The idea here was to build a little tank of a lathe with only the basics,
which you could build up as you go along. First you make a speed lathe;
learn some freehand turning and spin-forming; then add a tailstock; (do some
wood-turning); then a cross slide (using it like a gang-turn Wasino), and
eventually, a compound. You could add a power Z-axis feedscrew and my
thought at the time (around 1980) was that CNC was going to become cheap
enough that you might never have geared thread-cutting at all, going
straight to servos for CNC threading.

The reason for the ferrocement over other kinds of reinforced concrete was
twofold. First, it allows free-form shapes, so you could make the headstock
a hollow monocoque type, like modern lathes, rather than deal with the lack
of lateral (X-axis) flexibility of old designs with pillow-block or
stantion-type bearing supports. The structure of the bed would be a torque
box, rather than parallel beams. That would give you rigidity throughout,
without adding a lot of mass.

The second reason is that it's isotropic; you don't have to engineer around
the lines of tensile stress that can be tolerated. It's more like a metal
than reinforced concrete in its mechanical properties. That's easier for us
amateurs.

It wasn't really a conventional design but it combined separate elements of
well-tried lathe types. I had some suppositions about the ability of
ferrocement to handle tensile loads which I've since learned, after reading
Naaman's book, *are not exactly true. (It will handle the loads, but it will
microcrack under tension).

But ferrocement still has some big advantages over other kinds of
reinforcement. It still could be the best choice, perhaps with a bit of
hybridization, using post-tensioned tendons at the bottoms of the lathe bed,
or maybe some fibers to prevent microcracks. 'Dunno. If I get some time,
I'll have to re-think it now that I have the engineering data to help me
along.

That does allow a higher reduction ratio, and
perhaps a crank handle for threading to a shoulder. Schedule 80 pipe
might have enough wall thickness to make a bearing seat and you could
clamp the bearings with bored-out pipe caps, as long as you can get
the pipe to run true both ways to make the seats parallel.


The idea here was to turn a piece of tubing of some sort to all of the
inside and outside dimensions, including threading for the bearing
retainers, to within a couple of thousandths. One hopes that you have a
friend with a lathe. g Or, if it was a club-type project, these parts
could be made and sold.

Then make a rig that fits tightly into the bore and which has three pads
that rest on the bedways to align the spindle-holding tube close enough
while the structure is curing that you could hone the tube bore to final
dimensions, without a lot of wasted effort.

I would rather be able to adjust the spindle vertically for the Z axis
milling feed, or to turn an oversized pulley or bore a taper in the
spindle end.


OK, there's a lot of room for variation in the basic idea.



I don't see the spindle heating and expanding enough to cause a
problem with the relatively light and flexible bearing support
framework of a homebrew machine.


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the tail
end of the spindle was held in a single- or double-row bearing that allowed
linear movement -- either straight rollers, or ball bearings that allow the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).

Anyway, it's been a good thought exercise for me from time to time. My ideas
about it have changed a bit, but, basically, the objective is to design a
lathe that a determined amateur with no experience could build at home. Some
parts are tricky and will require machining; I've never worked out a really
good saddle, cross-slide, and compound that can be made easily at home.

As I said, I see it as a progressive design. You could start using it as
soon as you complete the basic steps, learning and gaining some experience
while making some fun and useful things, and then build it up in stages to a
full-blown thread-cutting engine lathe. With CNC threading, no less. g

I would love to see someone with more time and the ambition for it take some
of these thoughts and carry it through. I've been diddling with it for so
long that I'm losing heart to do it.

--
Ed Huntress


I used different design criteria, this machine would take on
occasional jobs too large for my lathe and mill. That means it can be
built lighter and cheaper than normal and only have to take finishing
cuts on pieces roughed out with a saw or cutting torch.
(pause to watch Mya dance)
As a bootstrap machine it could make parts to upgrade itself.

The other similar project is a Harig-style cylindrical and tool
grinding attachment for my Toolmaker surface grinder, to make it more
like a Quorn.

This would resemble a small and precise lathe headstock and spindle
that includes sliding motion. The 5C spindle of a spin index might be
a decent start if it can be cleaned up well enough and converted to an
air bearing. The grinder has a Y leadscrew so the Quorn's complexity
can be reduced.

I bought a Morse taper adapter with the outside ground to 1.000 OD for
this project and discovered that it had bulged slightly around the
release key slot.

jsw
  #28   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Jim Wilkins" wrote in message
...
On Nov 24, 8:38 pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message

...
On Nov 24, 6:42 pm, "Ed Huntress" wrote:





"Jim Wilkins" wrote in message


Interesting, but I think you'd have growth problems at the back end,
unless
you made the spindle float in the inner race of the backside bearing --
or
had the backside bearings run right on the spindle, with clearance.


I'd use a tubular bearing holder (a piece of pipe) cast into a
ferrocement
headstock, with floating rollers at the tail end and a pair of facing
tapered roller bearings on the head end. That's one traditional setup
for
lathes, and it combines Z-axis stability, high load capacity, and
free-floating at the tail end to deal with Z-axis growth of the spindle.


I'd have to look at what kinds of bearings are cheaply available first.
Ed Huntress-
So you have the drive pulley on the end of the spindle instead of
between the bearings?


Yeah, I worked that out in one of my first sketches, and I saw no real
disadvantage. I was thinking about a pretty large (2 inch) hollow spindle.
In my original version, I didn't even have a drive or gears for threading.
It was going to use thread follower attachments, like the ones used on an
old Unimat or some screw machines.

The idea here was to build a little tank of a lathe with only the basics,
which you could build up as you go along. First you make a speed lathe;
learn some freehand turning and spin-forming; then add a tailstock; (do
some
wood-turning); then a cross slide (using it like a gang-turn Wasino), and
eventually, a compound. You could add a power Z-axis feedscrew and my
thought at the time (around 1980) was that CNC was going to become cheap
enough that you might never have geared thread-cutting at all, going
straight to servos for CNC threading.

The reason for the ferrocement over other kinds of reinforced concrete was
twofold. First, it allows free-form shapes, so you could make the
headstock
a hollow monocoque type, like modern lathes, rather than deal with the
lack
of lateral (X-axis) flexibility of old designs with pillow-block or
stantion-type bearing supports. The structure of the bed would be a torque
box, rather than parallel beams. That would give you rigidity throughout,
without adding a lot of mass.

The second reason is that it's isotropic; you don't have to engineer
around
the lines of tensile stress that can be tolerated. It's more like a metal
than reinforced concrete in its mechanical properties. That's easier for
us
amateurs.

It wasn't really a conventional design but it combined separate elements
of
well-tried lathe types. I had some suppositions about the ability of
ferrocement to handle tensile loads which I've since learned, after
reading
Naaman's book, are not exactly true. (It will handle the loads, but it
will
microcrack under tension).

But ferrocement still has some big advantages over other kinds of
reinforcement. It still could be the best choice, perhaps with a bit of
hybridization, using post-tensioned tendons at the bottoms of the lathe
bed,
or maybe some fibers to prevent microcracks. 'Dunno. If I get some time,
I'll have to re-think it now that I have the engineering data to help me
along.

That does allow a higher reduction ratio, and
perhaps a crank handle for threading to a shoulder. Schedule 80 pipe
might have enough wall thickness to make a bearing seat and you could
clamp the bearings with bored-out pipe caps, as long as you can get
the pipe to run true both ways to make the seats parallel.


The idea here was to turn a piece of tubing of some sort to all of the
inside and outside dimensions, including threading for the bearing
retainers, to within a couple of thousandths. One hopes that you have a
friend with a lathe. g Or, if it was a club-type project, these parts
could be made and sold.

Then make a rig that fits tightly into the bore and which has three pads
that rest on the bedways to align the spindle-holding tube close enough
while the structure is curing that you could hone the tube bore to final
dimensions, without a lot of wasted effort.

I would rather be able to adjust the spindle vertically for the Z axis
milling feed, or to turn an oversized pulley or bore a taper in the
spindle end.


OK, there's a lot of room for variation in the basic idea.



I don't see the spindle heating and expanding enough to cause a
problem with the relatively light and flexible bearing support
framework of a homebrew machine.


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose
end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the
tail
end of the spindle was held in a single- or double-row bearing that
allowed
linear movement -- either straight rollers, or ball bearings that allow
the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which
will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).

Anyway, it's been a good thought exercise for me from time to time. My
ideas
about it have changed a bit, but, basically, the objective is to design a
lathe that a determined amateur with no experience could build at home.
Some
parts are tricky and will require machining; I've never worked out a
really
good saddle, cross-slide, and compound that can be made easily at home.

As I said, I see it as a progressive design. You could start using it as
soon as you complete the basic steps, learning and gaining some experience
while making some fun and useful things, and then build it up in stages to
a
full-blown thread-cutting engine lathe. With CNC threading, no less. g

I would love to see someone with more time and the ambition for it take
some
of these thoughts and carry it through. I've been diddling with it for so
long that I'm losing heart to do it.

--
Ed Huntress


I used different design criteria, this machine would take on
occasional jobs too large for my lathe and mill. That means it can be
built lighter and cheaper than normal and only have to take finishing
cuts on pieces roughed out with a saw or cutting torch.
(pause to watch Mya dance)
As a bootstrap machine it could make parts to upgrade itself.

The other similar project is a Harig-style cylindrical and tool
grinding attachment for my Toolmaker surface grinder, to make it more
like a Quorn.

This would resemble a small and precise lathe headstock and spindle
that includes sliding motion. The 5C spindle of a spin index might be
a decent start if it can be cleaned up well enough and converted to an
air bearing. The grinder has a Y leadscrew so the Quorn's complexity
can be reduced.

I bought a Morse taper adapter with the outside ground to 1.000 OD for
this project and discovered that it had bulged slightly around the
release key slot.


Those sound like good projects, too. Regarding the big machine, things like
gap-bed lathes with big swings are a natural for the ferrocement
construction method. You can span long distances at very low cost. It's also
a good place for cylindrical bedways. The travels typically are short, and
you have plenty of room to make their diameter as large as you need.

In fact, a big gap-bed lathe with short tool travels would be easier than a
thread-cutting engine lathe by a wide margin. If you have to face big disks,
however, the whole prospect is a lot more difficult.

--
Ed Huntress


  #29   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,803
Default Which tool is needed. . . ?

On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
wrote:


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the tail
end of the spindle was held in a single- or double-row bearing that allowed
linear movement -- either straight rollers, or ball bearings that allow the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).


Hardinge uses a single pair of angular contact bearings, one bearing
at either end of the spindle, in the HLVH headstock -- a 3000RPM
spindle with 25 millionths runout. The preload is controlled by a pair
of spacers that introduce an offset between the inner and outer races.
The drive belt is outboard of the rear bearing.

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.

--
Ned Simmons
  #30   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Ned Simmons" wrote in message
...
On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
wrote:


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose
end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the
tail
end of the spindle was held in a single- or double-row bearing that
allowed
linear movement -- either straight rollers, or ball bearings that allow
the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which
will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).


Hardinge uses a single pair of angular contact bearings, one bearing
at either end of the spindle, in the HLVH headstock -- a 3000RPM
spindle with 25 millionths runout.


Hmm. Is that right? I thought Hardinges had the classic two-bearing-front,
floating rear setup. But I don't know for sure. Maybe Gunner would know.

In any case, they use Class 9 bearings in their top-of-the-line, and those
spindles run exceptionally cool. They aren't a good example to follow for
any ordinary lathe. You'd never be able to duplicate the performance of that
spindle.

The preload is controlled by a pair
of spacers that introduce an offset between the inner and outer races.
The drive belt is outboard of the rear bearing.

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.

--
Ned Simmons





  #31   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,803
Default Which tool is needed. . . ?

On Wed, 25 Nov 2009 00:18:26 -0500, "Ed Huntress"
wrote:


"Ned Simmons" wrote in message
.. .
On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
wrote:


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose
end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the
tail
end of the spindle was held in a single- or double-row bearing that
allowed
linear movement -- either straight rollers, or ball bearings that allow
the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which
will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).


Hardinge uses a single pair of angular contact bearings, one bearing
at either end of the spindle, in the HLVH headstock -- a 3000RPM
spindle with 25 millionths runout.


Hmm. Is that right? I thought Hardinges had the classic two-bearing-front,
floating rear setup. But I don't know for sure. Maybe Gunner would know.


It's as I've described. I've been in there and have a picture here in
front of me.


In any case, they use Class 9 bearings in their top-of-the-line, and those
spindles run exceptionally cool. They aren't a good example to follow for
any ordinary lathe. You'd never be able to duplicate the performance of that
spindle.


The key to controlling the temperature rise is more closely related to
accurately setting the preload than the bearing class. In order to get
reasonable stiffness you'd probably not want to mount the nose
bearings directly back to back, and the most practical way to get the
required separation is with a pair of spacers. The length of those
spacers is critical to setting the preload, regardless of how long
they are.

I've designed quite a few spindles, and I think temperature effects
are way down on the list of things to worry about when thinking about
buliding a ball bearing headstock on the cheap with limited equipment.


The preload is controlled by a pair
of spacers that introduce an offset between the inner and outer races.
The drive belt is outboard of the rear bearing.

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.

--
Ned Simmons



--
Ned Simmons
  #32   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 12,529
Default Which tool is needed. . . ?


"Ned Simmons" wrote in message
...
On Wed, 25 Nov 2009 00:18:26 -0500, "Ed Huntress"
wrote:


"Ned Simmons" wrote in message
. ..
On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
wrote:


In good lathe designs, I believe you'll find that the typical setup is
to
have a pair of preloaded bearings facing each other at the spindle-nose
end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the
tail
end of the spindle was held in a single- or double-row bearing that
allowed
linear movement -- either straight rollers, or ball bearings that allow
the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which
will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little
wider
and probably a little shorter (mine has the 54" bed).

Hardinge uses a single pair of angular contact bearings, one bearing
at either end of the spindle, in the HLVH headstock -- a 3000RPM
spindle with 25 millionths runout.


Hmm. Is that right? I thought Hardinges had the classic two-bearing-front,
floating rear setup. But I don't know for sure. Maybe Gunner would know.


It's as I've described. I've been in there and have a picture here in
front of me.


Ok, then maybe it's just the HLVH? Because I used a cutaway drawing of a
Hardinge spindle once to illustrate exactly what we've been talking about
here, and, although I don't remember the drawing perfectly, I do remember
what I wrote for the caption. Are you familiar with the earlier Hardinges?



In any case, they use Class 9 bearings in their top-of-the-line, and those
spindles run exceptionally cool. They aren't a good example to follow for
any ordinary lathe. You'd never be able to duplicate the performance of
that
spindle.


The key to controlling the temperature rise is more closely related to
accurately setting the preload than the bearing class. In order to get
reasonable stiffness you'd probably not want to mount the nose
bearings directly back to back, and the most practical way to get the
required separation is with a pair of spacers. The length of those
spacers is critical to setting the preload, regardless of how long
they are.

I've designed quite a few spindles, and I think temperature effects
are way down on the list of things to worry about when thinking about
buliding a ball bearing headstock on the cheap with limited equipment.


Aha. Are you saying you'd run opposed, preloaded bearings at opposite ends
of the spindle on a lathe like we've described here? Because I was once
pretty familiar with bearing layouts in machine tools, and it just goes
against everything I was taught. I'm not saying you're wrong, but there is a
pretty fair amount of work behind the things I thought I learned when I was
writing about it. If it's all wrong, I have some work to do here in a hurry.



The preload is controlled by a pair
of spacers that introduce an offset between the inner and outer races.
The drive belt is outboard of the rear bearing.

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.

--
Ned Simmons



--
Ned Simmons



  #33   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,502
Default Which tool is needed. . . ?

On Tue, 24 Nov 2009 23:36:11 -0500, Ned Simmons
wrote:

On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
wrote:


In good lathe designs, I believe you'll find that the typical setup is to
have a pair of preloaded bearings facing each other at the spindle-nose end.
In classic designs, these were angular tapered-roller bearings in larger
lathes, and angular-contact ball bearings in smaller ones. All of your
Z-axis location is accomplished with these head-end bearings. Then the tail
end of the spindle was held in a single- or double-row bearing that allowed
linear movement -- either straight rollers, or ball bearings that allow the
spindle to move.

It doesn't take much heat to make the spindle grow substantially, which will
either overload your bearings or unload the preload on the head-end
bearings. Also, this lathe is no wimp. It would handle much higher loads
than my SB-10L and would be roughly the same size, although a little wider
and probably a little shorter (mine has the 54" bed).


Hardinge uses a single pair of angular contact bearings, one bearing
at either end of the spindle, in the HLVH headstock -- a 3000RPM
spindle with 25 millionths runout. The preload is controlled by a pair
of spacers that introduce an offset between the inner and outer races.
The drive belt is outboard of the rear bearing.

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.



They can be..yes.

Good post btw.


Gunner
  #34   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,502
Default Which tool is needed. . . ?

On Wed, 25 Nov 2009 00:47:42 -0500, Ned Simmons
wrote:


Hmm. Is that right? I thought Hardinges had the classic two-bearing-front,
floating rear setup. But I don't know for sure. Maybe Gunner would know.


It's as I've described. I've been in there and have a picture here in
front of me.



Very early Hardinges had the 2 bearing front..1940s-early 50s
vintage..but since the late 50s..all have been as Ned said.

Thats for manual and microswitch automatics.

Gunner
  #35   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 852
Default Which tool is needed. . . ?

On Tue, 24 Nov 2009 19:09:44 -0800, Gunner Asch
wrote:

On Tue, 24 Nov 2009 22:46:10 +0000, Mark Rand
wrote:

(Hardinge Dovetail excepted, that works)



Indeed it does...and its actually 3 surfaces..or 5 if you are counting


Gunner



Oops. Miscounted there. I don't know where the extra one crept in from...

Very definitely only three guiding surfaces on the dovetail beds of the
Brothers Hardinge.

Regards
Mark Rand
RTFM


  #36   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,502
Default Which tool is needed. . . ?

On Wed, 25 Nov 2009 09:29:32 +0000, Mark Rand
wrote:

On Tue, 24 Nov 2009 19:09:44 -0800, Gunner Asch
wrote:

On Tue, 24 Nov 2009 22:46:10 +0000, Mark Rand
wrote:

(Hardinge Dovetail excepted, that works)



Indeed it does...and its actually 3 surfaces..or 5 if you are counting


Gunner



Oops. Miscounted there. I don't know where the extra one crept in from...

Very definitely only three guiding surfaces on the dovetail beds of the
Brothers Hardinge.

Regards
Mark Rand
RTFM


G

Gunner
  #37   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 24, 11:36*pm, Ned Simmons wrote:
On Tue, 24 Nov 2009 20:38:12 -0500, "Ed Huntress"
...

One problem with tapered roller bearings, depending on how fussy you
are, is that the runout specs on standard bearings is pretty bad
compared to run of the mill ball bearings. And precision grade roller
bearings are horribly expensive and can be difficult to source.

Ned Simmons-


Does bearing runout matter as much if you finish the spindle nose -
after- keying and clamping it in place?

For my version you swap spindles rather than making precise threads
and tapers on the nose, so keying or at least putting the clamp
setscrews back in the same depressions is important.

jsw
  #38   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 211
Default Which tool is needed. . . ?

On Nov 24, 8:04*am, Jim Wilkins wrote:
On Nov 24, 1:24*am, "RogerN" wrote:



A lathe can make another lathe, but a mill can not make another mill. *No
CNC's allowed.


What part of a mill can't a mill make? *How do you machine a lathe bed in a
lathe?


I think the idea is to remove the head and tailstock and use a tool
bit in the carriage to plane the ways. You might want to hang the new
lathe bed upside down over the old one so you can plane all the way
surfaces parallel.

When I needed to remachine a worn lathe bed I used a large horizontal
milling machine.



I think I'd prefer to use a mill to make 90% of either a lathe or a mill.
And for the other 10% I think it would be easier to make a spindle on a mill
than it would be to mill a cross slide table, but then again I've never seen
a very nice milling setup in a lathe.


RogerN


You can mill cylindrical or conical surfaces on a rotary table or
between indexer centers. That's how I make tubing bender dies. I
suppose you could cut threads with a vee cutter or a fixed flycutter
bit by gearing the indexer to the table feed.

The American Precision Museum in Vermont has machine tools going back
to 1820 or so. By about 1860 practical experience had shaped them into
the forms we still have now. The smaller details such as quick-change
gearboxes and HSS tool bits were in place by 1900.

There are some versatile hybrids meant for moderate production runs
such as the Lincoln miller, which would be my model for a machine that
makes other machines.http://www.sperdvac.org/Horizontal%2...ne_lincoln.jpg

I would make the tailstock support with two posts like the headstock
to better support it for tailstock drilling.

Scroll down to the bottom and look at "take-up" bearings:http://www.baileynet.com/index.php?i...tegory=1000011

jsw


The picture of the "Lincoln miller" seems to have a "Pratt & Whitney"
logo on the bed.
  #39   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,966
Default Which tool is needed. . . ?

In article ,
"Ed Huntress" wrote:

"Jim Wilkins" wrote in message
...
On Nov 24, 1:04 pm, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
I just checked my two best sources, Holtzapffel #2 and Oscar Perrigo's
1916 "Lathe Design", ...

...
As I think about this, I'm remembering what I thought about it at the
time,
30 years ago. I believed then that the issue was the difficulty, without
planers, mills, or big surface grinders, of getting the four planes of a
pair of V-ways coordinated for straight and smooth travel. One way to
interpret this is that you can adjust the single plane of the flat way a
lot
easier than the pair of planes you have with a second V. So to say that it
was simpler to correct accuracy with the V-and-flat could just mean that;
if
the ways are hand-finished, you're correcting accuracy, and V-and-flat is
a
lot easier to correct than two V's.

Maybe. g

--
Ed Huntress


If I read Holtzapffel correctly the two sides of inverted vee ways
were at first made separately, joined and aligned afterwards to fit
the fixed and moving poppit heads (headstock and tailstock to us).


Yeah. In the very beginning of modern lathes, the V-and-flat combinations
were assembled the same way. The first screw-cutting lathes had wood beds
with bolted-on iron ways, IIRC. (I'm doing this from memory; don't bite me.
g)

"This slight width of base does not afford sufficient lateral support
to the heads, which with only moderate force in turning are liable to
vibration; while exact parallelism of the two angular edged bars is
also necessary. Improvement in stability was sought by making one side
of the bearers flat and broad, fig. 72, with a corresponding flat on
the underside of the lathe heads; retaining one angular side, to give
the direction or common axis. This arrangement also facilitated the
construction, as the parallelism of the two bars was no longer
essential,..."


Right. That sounds familiar.


Fig 72 shows one flat and one inverted vee way on a cast iron bed.

The difficulties of the early machine builders that Holtzapffel
recorded aren't that much different from those of a homebrew machine
tool maker today, except that we can buy ground drill rod and flat
stock and they could hire cheap child labor for tedious hand fitting.


Right. Maybe you've peeked at my ideas for a ferrocement lathe with steel
ways. d8-)

(Having finished reading Naaman's _Ferrocement & Laminated Cementitious
Composites_, I'm less enthusiastic about that construction.)


Significant work has been done on concrete-filled fabricated metal
frames for precision machine tools.

The place to start is MIT professor Alexander H. Slocum
(http://meche.mit.edu:16080/people/index.html?id=80). A good discussion
and many references may be found in his book "Precision Machine Design".

Joe Gwinn
  #40   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,146
Default Which tool is needed. . . ?

On Nov 25, 7:37*am, "Denis G." wrote:
On Nov 24, 8:04*am, Jim Wilkins wrote:
...
Scroll down to the bottom and look at "take-up" bearings:http://www.baileynet.com/index.php?i...tegory=1000011


jsw


The picture of the "Lincoln miller" seems to have a "Pratt & Whitney"
logo on the bed.-


Here's a little of the interrelationship between the machine builders
of Hartford, which somewhat like Maudslay's group in England:
http://www.hogriver.org/issues/v02n03/miracle.htm

jsw
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Another tool ID needed XXV R.H. Metalworking 20 December 5th 04 04:00 PM
Another tool ID needed VII R.H. Woodworking 2 September 11th 04 10:50 AM
Another tool ID needed V R.H. Woodworking 25 September 8th 04 12:17 AM
Another tool ID needed VI R.H. Woodworking 7 September 6th 04 05:16 PM
Another tool ID needed III R.H. Woodworking 15 August 24th 04 10:08 PM


All times are GMT +1. The time now is 06:51 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"