OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

Andrew VK3BFA fired this volley in news:db3ca6b6-
:

No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.


You cannot assume the bed is level and true. That would be a fundamental
and fatal mistake. Beg, borrow, or steal one, or buy an inexpensive
Chinese version and true it up yourself before you use it. Truing a
level is quite easy; just make sure it can indicate 0.001" per foot.

CLEAN the level's base and the surface upon which you place it.

On small lathes that tend to flex a bit under cutting pressure, it's
common to have the tailstock center riding a couple of thousanths higher
than the spindle center. It should be dead-on fore and aft.

Note, I said, "center"(s). Clean the spindle bore and the tailstock
socket. Clean the centers. Gently "thump" them into place, but don't
drive them in. Make sure they have sharp, well-centered points. Don't
file them to a point, either have them re-turned on a precision lathe, or
buy some brand new ones.

After truing everything as well as you can, turn a "truing bar" between
centers, and as long as you can conveniently hold between the centers,
then check the diameters at both ends. If they're off, move the
tailstock fore or aft by half the error, and turn the bar's ends again to
check.

A truing bar is a length of stock that's thinner in the middle (by only,
say, 0.1") and with "hubs" on both ends upon which you do the actual cuts
for measuring. Take only very light cuts, and check frequently.

LLoyd

Andrew VK3BFA wrote:
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

DO NOT assume the bed is flat and true !! Beg borrow or steal a level ,
because you're just ****in' upwind otherwise .
Google "Rollie's Dad's Method" for a way to check if the head is aligned
with the ways . To check tailstock alignment I use a bar that's got a larger
diameter section on both ends/smaller in the center between centers . Make a
light cut at one end , then the other without moving the cross
slide/compound . Checking the resulting diameters will tell you whether the
tailstock is aligned horizontally or not , and how much it's out .
--
Snag
Learning keeps
you young !

Lloyd E. Sponenburgh wrote:
Andrew VK3BFA fired this volley in news:db3ca6b6-
:

No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.


You cannot assume the bed is level and true. That would be a
fundamental and fatal mistake. Beg, borrow, or steal one, or buy an
inexpensive Chinese version and true it up yourself before you use
it. Truing a level is quite easy; just make sure it can indicate
0.001" per foot.

CLEAN the level's base and the surface upon which you place it.

On small lathes that tend to flex a bit under cutting pressure, it's
common to have the tailstock center riding a couple of thousanths
higher than the spindle center. It should be dead-on fore and aft.

Note, I said, "center"(s). Clean the spindle bore and the tailstock
socket. Clean the centers. Gently "thump" them into place, but don't
drive them in. Make sure they have sharp, well-centered points.
Don't file them to a point, either have them re-turned on a precision
lathe, or buy some brand new ones.

After truing everything as well as you can, turn a "truing bar"
between centers, and as long as you can conveniently hold between the
centers, then check the diameters at both ends. If they're off, move
the tailstock fore or aft by half the error, and turn the bar's ends
again to check.

A truing bar is a length of stock that's thinner in the middle (by
only, say, 0.1") and with "hubs" on both ends upon which you do the
actual cuts for measuring. Take only very light cuts, and check
frequently.

LLoyd

Damn , Lloyd , I just told him almost exactly the same thing !

Great minds and all that ...

--
Snag
Learning keeps
you young !

On Mon, 20 Jun 2011 08:27:25 -0500, "Snag"
wrote:

Andrew VK3BFA wrote:
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

DO NOT assume the bed is flat and true !! Beg borrow or steal a level ,
because you're just ****in' upwind otherwise .
Google "Rollie's Dad's Method" for a way to check if the head is aligned
with the ways . To check tailstock alignment I use a bar that's got a larger
diameter section on both ends/smaller in the center between centers . Make a
light cut at one end , then the other without moving the cross
slide/compound . Checking the resulting diameters will tell you whether the
tailstock is aligned horizontally or not , and how much it's out .

DAMN. I seen Loyd missed "Rollies dad's method". I was all ready to
chime in. Guess I got nothin' else to day.

Do what snag says.

"Andrew VK3BFA" wrote in message
...
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

To not level the lathe isn't a wise decision. Only when the bed is level
(in a common plane, even if it's not really level) can you do any meaningful
adjustments. If you rely on the chuck and tailstock, you may get the
reading to come true by tweaking the bed, or it may indicate it's true when
it's not, but that doesn't translate to a properly setup lathe. Beg,
borrow, or steal a decent level to get started. You can have minor twist
in the bed and not be any the wiser. If you happen to have, all your
setup time is wasted. Remember, the real purpose of a level isn't to
*truly* level the lathe, although getting it level is easier than trying to
remember how much error you have end to end, so you can duplicate the error.
The real purpose is to insure that the bed isn't twisted.

Harold

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
snip---


You cannot assume the bed is level and true. That would be a fundamental
and fatal mistake. Beg, borrow, or steal one,

Heh! Believe it or not, I said the same thing, even before reading your
response.

It's comforting to be in the company of wise people.

Harold

"Snag" wrote in message
...
snip---!! Beg borrow or steal a level ,

Chuckle!

You too, eh?

Harold

"Karl Townsend" wrote in message
...
snip---
DAMN. I seen Loyd missed "Rollies dad's method". I was all ready to
chime in. Guess I got nothin' else to day.


If memory serves, that will get the tailstock in proper alignment with the
spindle for a given length, but may or may not reflect a bed that is not
properly leveled. You'd make adjustments by setting over the tailstock,
that would yield a straight turn, that's true, but that may not reflect a
true condition of the bed as it relates to the spindle. Chucking a short
piece of large diameter stock would likely disclose error because of twist
in the bed. That's the condition that is addressed by the use of a level.

Harold

On Tue, 21 Jun 2011 06:02:24 GMT, "Harold & Susan Vordos"
wrote:


"Andrew VK3BFA" wrote in message
...
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

To not level the lathe isn't a wise decision. Only when the bed is level
(in a common plane, even if it's not really level) can you do any meaningful
adjustments. If you rely on the chuck and tailstock, you may get the
reading to come true by tweaking the bed, or it may indicate it's true when
it's not, but that doesn't translate to a properly setup lathe. Beg,
borrow, or steal a decent level to get started. You can have minor twist
in the bed and not be any the wiser. If you happen to have, all your
setup time is wasted. Remember, the real purpose of a level isn't to
*truly* level the lathe, although getting it level is easier than trying to
remember how much error you have end to end, so you can duplicate the error.
The real purpose is to insure that the bed isn't twisted.

Harold

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.

I own the level and would probably get the next lathe close. But the
proof is in how it cuts. IMHO, skipping the level step on small lathes
might not hurt that much.

Karl

Karl Townsend fired this volley in
:

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.


I'll bet dollars to dougnuts that your headstock was/is out of alignment
with the bed. Unless there's a serious belly in the ways, and you're
cutting _exactly_ on the center of the work, a leveled and trued bed
cannot turn taper from the chuck unless the headstock is mis-aligned.

Rather than "not being a fan of leveling", I'd take it that your leveling
exercise disclosed a previously unknown problem. In fact, it did its job
perfectly, and I'm afraid you've perverted your setup to accommodate the
problem, rather than fixing it.

Headstocks _do_ get mis-aligned.

LLoyd

On Jun 21, 2:09*am, "Harold & Susan Vordos" wrote:
...
If memory serves, that will get the tailstock in proper alignment with the
spindle for a given length, but may or may not reflect a bed that is not
properly leveled. * You'd make adjustments by setting over the tailstock,
that would yield a straight turn, that's true, but that may not reflect a
true condition of the bed as it relates to the spindle. *Chucking a short
piece of large diameter stock would likely disclose error because of twist
in the bed. * That's the condition that is addressed by the use of a level.

Harold

If you slid the tailstock close to the headstock and aligned them with
the tailstock offset, then slid the tailstock to the end and shimmed
the bed to turn (or indicate) the same diameter at both ends, wouldn't
the bed and tailstock be correctly adjusted?

I have one of these South Bends on a sheet-metal cabinet.
http://users.consolidated.net/jimkull/10LDRO2.jpg
The tailstock end sits on a lengthwise pivot rod that lets the bed
straighten itself when the two opposing clamp screws are loosened. The
front one is within the red circle on the foot, a brass plate marked
"leveling screw".

The lathe has been temporarily parked on blocks where it was delivered
for the last 20 years and the head end isn't level. I shimmed the
level at the spindle to align one end of the bubble with a mark and
then moved level and shim to the tail end to put the bubble in the
same place with the leveling screws. It's not level but the tilt is
the same at both ends.
-----
Just rechecked. The rear way is 0.032" low at both ends. A genuine
South Bend lathe level is about 1/4 as sensitive as a VIS that reads
0.0005IN/10IN.

jsw

On Tue, 21 Jun 2011 04:46:07 -0700 (PDT), Jim Wilkins
wrote:

On Jun 21, 2:09Â*am, "Harold & Susan Vordos" wrote:
...
If memory serves, that will get the tailstock in proper alignment with the
spindle for a given length, but may or may not reflect a bed that is not
properly leveled. Â* You'd make adjustments by setting over the tailstock,
that would yield a straight turn, that's true, but that may not reflect a
true condition of the bed as it relates to the spindle. Â*Chucking a short
piece of large diameter stock would likely disclose error because of twist
in the bed. Â* That's the condition that is addressed by the use of a level.

Harold

If you slid the tailstock close to the headstock and aligned them with
the tailstock offset, then slid the tailstock to the end and shimmed
the bed to turn (or indicate) the same diameter at both ends, wouldn't
the bed and tailstock be correctly adjusted?

I have one of these South Bends on a sheet-metal cabinet.
http://users.consolidated.net/jimkull/10LDRO2.jpg

Dayum, is that a 500 hour rebuild? Fair lady!



The tailstock end sits on a lengthwise pivot rod that lets the bed
straighten itself when the two opposing clamp screws are loosened. The
front one is within the red circle on the foot, a brass plate marked
"leveling screw".

The lathe has been temporarily parked on blocks where it was delivered
for the last 20 years and the head end isn't level. I shimmed the
level at the spindle to align one end of the bubble with a mark and
then moved level and shim to the tail end to put the bubble in the
same place with the leveling screws. It's not level but the tilt is
the same at both ends.

Until this thread today, I had wondered why people went to so much
trouble to level a lathe. It wasn't until I saw the word "twist" that
I realized they were leveling it both ways, not just lengthwise.
DUH! whap, whap, whap


Just rechecked. The rear way is 0.032" low at both ends. A genuine
South Bend lathe level is about 1/4 as sensitive as a VIS that reads
0.0005IN/10IN.

You did that to enhance way oil migration, right?

--
"Human nature itself is evermore an advocate for liberty.
There is also in human nature a resentment of injury, and
indignation against wrong. A love of truth and a veneration
of virtue. These amiable passions, are the latent spark. If
the people are capable of understanding, seeing and feeling
the differences between true and false, right and wrong,
virtue and vice, to what better principle can the friends of
mankind apply than to the sense of this difference?"
--John Adams

On Tue, 21 Jun 2011 06:38:52 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Karl Townsend fired this volley in
:

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.


I'll bet dollars to dougnuts that your headstock was/is out of alignment
with the bed. Unless there's a serious belly in the ways, and you're
cutting _exactly_ on the center of the work, a leveled and trued bed
cannot turn taper from the chuck unless the headstock is mis-aligned.

Rather than "not being a fan of leveling", I'd take it that your leveling
exercise disclosed a previously unknown problem. In fact, it did its job
perfectly, and I'm afraid you've perverted your setup to accommodate the
problem, rather than fixing it.

Headstocks _do_ get mis-aligned.


I'm sure you're technically correct. No doubt this lathe had a schmuck
in its past. But raising one leg and test cutting took maybe an hour
tops. Tearing the headstock off and re pinning or grinding etc.
*should* fix it at a cost of many hours. For most, my suggestion is
just make it cut the best you can without a rebuild.

Now if you're making parts for NASA or Medtronic, this advice would
not apply.

Karl


Karl
LLoyd

"Karl Townsend" wrote in message
...
On Tue, 21 Jun 2011 06:38:52 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Karl Townsend fired this volley in
m:

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.


I'll bet dollars to dougnuts that your headstock was/is out of alignment
with the bed. Unless there's a serious belly in the ways, and you're
cutting _exactly_ on the center of the work, a leveled and trued bed
cannot turn taper from the chuck unless the headstock is mis-aligned.

Rather than "not being a fan of leveling", I'd take it that your leveling
exercise disclosed a previously unknown problem. In fact, it did its job
perfectly, and I'm afraid you've perverted your setup to accommodate the
problem, rather than fixing it.

Headstocks _do_ get mis-aligned.


I'm sure you're technically correct. No doubt this lathe had a schmuck
in its past. But raising one leg and test cutting took maybe an hour
tops. Tearing the headstock off and re pinning or grinding etc.
*should* fix it at a cost of many hours. For most, my suggestion is
just make it cut the best you can without a rebuild.

Now if you're making parts for NASA or Medtronic, this advice would
not apply.


Leveling is especially important for shipboard use.

--

The bed isn't flat or true, and if one were to adjust it so it was perfect,
it won't stay that way unless the environment is tightly controlled.

That's why companys involved in real precision construct underground
facilities.

Generally, for light-duty machines, the bed will flex.. and how much depends
upon the type of cuts being made at any particular time.

So I get a benchtop lathe from China, and decide to adjust it to a fair
degree of accuracy.. you know, to be able to submit a bid to manufacture
ultra-precise parts for a defence contractor.

There isn't much use in spending a lot of time/effort trying to get a
light-duty machine to register as perfectly straight.. because it won't be
tomorrow.

One can generally check a machine for straight/true if they want to be
disappointed about the money they spent.. otherwise, just make the parts fit
properly.

The benefit of having machines and tools is that now parts can be made to
fit properly.

If the part needs to be an accurate size, for say a press-fit bearing, then
measure it as the metal is being removed, not after.
A lot of low cost machines can't hold much accuracy to their dials' markings
because the screws aren't precise (that's only one factor).

When one is attempting to check a lathe for accuracy over a length of stock,
with the test piece between centers, the first thing to check would be the
spindle center to make sure the point is concentric to the spindle's axis..
and touch up the center if needed.
If a discrepancy in accuracy exists in the spindle, the center would need to
be retouched after every time it's reinserted, to compensate for the error.

For a workpiece that's chucked, the area that's cut will still be concentric
to the spindle's axis, which may not (most likely not) be concentric to any
other dimensions of the workpiece.. and the cut area of the workpiece may
exhibit a taper (depending upon several factors).

--
WB
..........


"Andrew VK3BFA" wrote in message
...
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

"PrecisionmachinisT" fired this volley in
:


Leveling is especially important for shipboard use.

Some of the bigger machines I saw on a mechanical tender in RVN had granite
slabs upon which the machines were mounted as a "false deck", because the
real decks could warp in heavy seas.

That's sorta-like the little concrete table I made for my 6x24 Atlas
decades ago, except mine was the table top, rather than the floor.

LLoyd

On Tue, 21 Jun 2011 11:21:24 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"PrecisionmachinisT" fired this volley in
:


Leveling is especially important for shipboard use.

Some of the bigger machines I saw on a mechanical tender in RVN had granite
slabs upon which the machines were mounted as a "false deck", because the
real decks could warp in heavy seas.

That's sorta-like the little concrete table I made for my 6x24 Atlas
decades ago, except mine was the table top, rather than the floor.

LLoyd
Greetings Lloyd,
Years ago I did some volunteer work on a Lightship. This boat was
called the "RELIEF" and was used to relieve other Lightships that were
doing the same duty as a lighthouse. There was a machine shop on board
and all the machines were leather belt drive. The lathe and mill were
adapted to ship use. I remember the lathe particularly. It was
originally made to be bolted to legs but was instead bolted to a thick
(about 1 inch) steel bench. Granite slabs would make a much better
mounting base. Lighter and stiffer. I wonder if subs use the same
thing? I had a friend who was stationed on a nuclear sub years ago. He
did some type of maintenance work and told me the machine shop was
usually busy.
Eric

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"PrecisionmachinisT" fired this volley in
:


Leveling is especially important for shipboard use.

Some of the bigger machines I saw on a mechanical tender in RVN had
granite
slabs upon which the machines were mounted as a "false deck", because the
real decks could warp in heavy seas.

That's sorta-like the little concrete table I made for my 6x24 Atlas
decades ago, except mine was the table top, rather than the floor.



Zoom....

--

"PrecisionmachinisT" fired this volley in
news:ItednWiCaM2sep3TnZ2dnUVZ_gWdnZ2d@scnresearch. com:

Zoom....


???

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"PrecisionmachinisT" fired this volley in
news:ItednWiCaM2sep3TnZ2dnUVZ_gWdnZ2d@scnresearch. com:

Zoom....


???


On a rocking ship, a level.is more useless than a lawnmower.

--

"PrecisionmachinisT" fired this volley in
news:jsGdnfYr1aSnbp3TnZ2dnUVZ_rudnZ2d@scnresearch. com:

On a rocking ship, a level.is more useless than a lawnmower.


OhhhKay... I guess I wasn't referring to "level", but how to keep a lathe
true on a deck that might bend under it.

I don't know, but they might've even trucked those lathes into the
maintenance bay pre-mounted AND pre-trued on those big slabs. For sure,
they won't warp before they break.

Actual _level_ isn't all that important unless you're turning really
heavy work with a long overhang. Close is good on leveling, truing must
be perfect.

LLoyd

On Tue, 21 Jun 2011 04:29:36 -0500, Karl Townsend
wrote:

On Tue, 21 Jun 2011 06:02:24 GMT, "Harold & Susan Vordos"
wrote:


"Andrew VK3BFA" wrote in message
...
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

To not level the lathe isn't a wise decision. Only when the bed is level
(in a common plane, even if it's not really level) can you do any meaningful
adjustments. If you rely on the chuck and tailstock, you may get the
reading to come true by tweaking the bed, or it may indicate it's true when
it's not, but that doesn't translate to a properly setup lathe. Beg,
borrow, or steal a decent level to get started. You can have minor twist
in the bed and not be any the wiser. If you happen to have, all your
setup time is wasted. Remember, the real purpose of a level isn't to
*truly* level the lathe, although getting it level is easier than trying to
remember how much error you have end to end, so you can duplicate the error.
The real purpose is to insure that the bed isn't twisted.

Harold

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.

I own the level and would probably get the next lathe close. But the
proof is in how it cuts. IMHO, skipping the level step on small lathes
might not hurt that much.

Karl


Much of this has been said before but it's perhaps worth
summarising.

With normal ( anything short of Gigantic! ) lathes errors arising
from the direction of gravity are negligible so absolute level is
unimportant. Bed level to within a few degrees is more than
good enough. However, dependent on how it is mounted, the long
narrow length of the bed is relatively easily twisted.

A precision level is commonly used to check bed twist by noting
the change in bubble position as it is placed at different
positons along the bed . This has to be done pretty carefully to
be sure that dirt is not affecting the measurement and that the
chosen surfaces are accurately representative of the surfaces
that actually guide the carriage. It's also necessary for the
lathe to be first levelled to within the very narrow range of
available bubble movement.

An alternative method is to first place the level on the
carriage and adjust with shims to approximately centre the
bubble. The carriage can now be traversed over its full range.
The bubble movement now directly indicates the twist (and wear
errors) in the guidance surfaces.

While it's interesting to know how the bed is behaving, the
usual end aim is to set up the lathe so that the tool as
supported by the carriage moves accurately parallel to the axis
of rotation of the headstock spindle i.e. it cuts a true constant
diameter workpieces. This can be done elegantly and accurately
By " Rollie Dads Method". This does not require a precision level
or even an accurately straight test bar.

Whichever method is used, care is needed in the method of
correcting the twist. While shims or screw adjustment between
the lathe and a very solid stiff surface would seem desirable
it needs extraordinary fine adjustment to reach the desirable
tenths accuracy . In addition, undesirable stresses result
unless the mounting surface has both similar thermal expansion
coeficient and thermal time constant.

Many manufacturers use the simpler solution of mounting the lathe
on a comparatively flimsy sheet metal cabinet. In this case the
torsional stiffness of the cabinet is much less tha the lathe
bed and this means the effect of screw or shim adjustment is
divided between the cabinet and the bed and it becomes much
less critical.

The twist adjustment should be between the bed feet and the
cabinet. The location of the cabinet feet is relatively
unimportant and may even be rubber mounted.

Jim

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"PrecisionmachinisT" fired this volley in
news:jsGdnfYr1aSnbp3TnZ2dnUVZ_rudnZ2d@scnresearch. com:

On a rocking ship, a level.is more useless than a lawnmower.


OhhhKay... I guess I wasn't referring to "level", but how to keep a lathe
true on a deck that might bend under it.


Sorry, but I couldn't resist..


I don't know, but they might've even trucked those lathes into the
maintenance bay pre-mounted AND pre-trued on those big slabs. For sure,
they won't warp before they break.

Actual _level_ isn't all that important unless you're turning really
heavy work with a long overhang. Close is good on leveling, truing must
be perfect.


When you think about it, the machine that ground the ways would have had to
be perfectly "earth level" in order for it to be able to grind ways that
would end up being "earth level"...and so on...

The reality is, "earth level" is nothing more than a good reference point
that you can always to go back to if things seem to be getting worse instead
of better after you've started into fiddling around with the jackscrews.

That said, where you have a vertical column bed mill with 4 or 6 leveling
jacks, you most certainly can obtain better z axis perpendicularity by
taking it slightly off-level.....

....BUT...

--You still need to insure that there is roughly equal weight being borne by
ALL of the feet or else you are going to find that the bed will have warped
and the whole works is messed up probably even worse than before after just
a few days have passed.

"Jim Wilkins" wrote in message
...
On Jun 21, 2:09 am, "Harold & Susan Vordos" wrote:
...
If memory serves, that will get the tailstock in proper alignment with the
spindle for a given length, but may or may not reflect a bed that is not
properly leveled. You'd make adjustments by setting over the tailstock,
that would yield a straight turn, that's true, but that may not reflect a
true condition of the bed as it relates to the spindle. Chucking a short
piece of large diameter stock would likely disclose error because of twist
in the bed. That's the condition that is addressed by the use of a level.

Harold

If you slid the tailstock close to the headstock and aligned them with
the tailstock offset, then slid the tailstock to the end and shimmed
the bed to turn (or indicate) the same diameter at both ends, wouldn't
the bed and tailstock be correctly adjusted?
***************

Not necessarily.
Tailstock adjustment isn't as simple as just having the alignment front to
back. Because height is rarely the same as the spindle, you actually
compromise the tailstock offset so the end result is a straight turn. I'm
not suggesting that it's a great amount, but it's a part of the process when
taking taper out. What appears to be a slight misalignment may yield a
straight turn (between centers). Starting with the bed level, end to end,
is really a good idea. As you alluded, it may be low in front or back by
an equal amount----which really makes no difference. Just insure that it's
not twisted---that's really what leveling is all about.

Harold

"Karl Townsend" wrote in message
...
On Tue, 21 Jun 2011 06:02:24 GMT, "Harold & Susan Vordos"
wrote:


"Andrew VK3BFA" wrote in message
...
OK, whats the preffered way of doing the horizontal and vertical
alignment of the headstock and tailstock. I have a calibrated bar and
finger indicator. No machinists level, so will take it as a given the
bed is flat and true.

Is it between centres each end. (my first choice.)

If you did it using the 3-jaw chuck and the dead centre at the
tailstock method, as I have seen in places, would this not just
introduce more error into the process as the 3-jaw certainly aint
true ...and it would give a different offset every time you chucked
something up anyway.

Replies appreciated,

Andrew VK3BFA.

To not level the lathe isn't a wise decision. Only when the bed is
level
(in a common plane, even if it's not really level) can you do any
meaningful
adjustments. If you rely on the chuck and tailstock, you may get the
reading to come true by tweaking the bed, or it may indicate it's true
when
it's not, but that doesn't translate to a properly setup lathe. Beg,
borrow, or steal a decent level to get started. You can have minor twist
in the bed and not be any the wiser. If you happen to have, all your
setup time is wasted. Remember, the real purpose of a level isn't to
*truly* level the lathe, although getting it level is easier than trying
to
remember how much error you have end to end, so you can duplicate the
error.
The real purpose is to insure that the bed isn't twisted.

Harold

Based on my experience with one lathe, I'm no longer a great fan of
leveling. I bought a very expensive level for our Mazak M4 lathe,
16,000 lb. 22" X 72", and leveled it perfectly.

Then chucked a 30" long 6" diameter rod. The idea here was the biggest
thing that could be run without a tailstock. A light cut showed a
taper. Started raising one of the legs on the tailstock end and got it
to cut true. Anyway, level shows twist, machine runs right.

I own the level and would probably get the next lathe close. But the
proof is in how it cuts. IMHO, skipping the level step on small lathes
might not hurt that much.

Karl


My concern would be tool pressure deflection. If you achieve repeatable
results with various materials, then I'd agree, level, at least for your
machine, may not be important. However, it may reflect the fact that the
spindle is not parallel to the ways. If that's the case, twisting the bed
can resolve the issue, assuming it's twisted in the proper direction.
Problem is, it's difficult to make the determination----which is why
leveling is recommended. That makes the reference plane easy to remember.

My Sag 12 Graziano has twist in the bed, and always has had, from the day it
was received (bought new back in '67). In my case, were it a big enough
problem, all I'd have to do is shim on the back side at the tailstock,
between the bed and base/chip pan, which, on the Graziano, is a very heavy
iron casting. Plain and simple, they screwed up when the lathe was
assembled.

Harold

On Jun 22, 12:46*am, "Harold & Susan Vordos" wrote:
...
My Sag 12 Graziano has twist in the bed, and always has had, from the day it
was received (bought new back in '67). * In my case, were it a big enough
problem, all I'd have to do is shim on the back side at the tailstock,
between the bed and base/chip pan, which, on the Graziano, is a very heavy
iron casting. *Plain and simple, they screwed up when the lathe was
assembled.

Harold-

So you know about the inaccuracy and have learned to live with it.

I don't turn thick press rolls. When I make an axle or such the
critical diameter sections aren't very long so deflection can be a
bigger source of taper error than lathe misalignment.
https://picasaweb.google.com/KB1DAL/...44360314674306
The general class is machine structural elements that need strength in
the middle and attachments at the ends, and may be too rough to run in
steady rests, steam engine rods for instance.

Do you know any good tricks for turning thin cylinders, particularly
on a lathe that lacks the collets and follower rest I use?

jsw

My concern would be tool pressure deflection. If you achieve repeatable
results with various materials, then I'd agree, level, at least for your
machine, may not be important. However, it may reflect the fact that the
spindle is not parallel to the ways. If that's the case, twisting the bed
can resolve the issue, assuming it's twisted in the proper direction.
Problem is, it's difficult to make the determination----which is why
leveling is recommended. That makes the reference plane easy to remember.


Yep, its important to remember the lathe and part is made of cheese.
it deflects under load. This effect is far larger than any alignment
issues. acutually easier to handle on the cnc, just command a taper
cut.

Now trying to hold a couple tenths on a long part in a manual lathe is
a real challenge. Thats why they pay real machinists the big bucks.

Karl

On Jun 22, 9:42*pm, Karl Townsend
wrote:

Isn't that why there are big, solid lathes, rather than just the
machinists skills?

Now trying to hold a couple tenths on a long part in a manual lathe is
a real challenge. Thats why they pay real machinists the big bucks.

Karl

Hi Karl,
thanks - to all - lots of information to assimilate, sort out,
examine, - . I have used 2 sorts of lathes - my Chinese one at home,
the big industrial machines at school. I can work to tolerance on the
school ones, I cant do it at home. I have learnt how to do a lot of
things, but not getting the machine time to get competent. So, I ask.
Hence my question - whats better to align between, centres or chuck
and centre? Because the way it is is total crap - very limited, and
horrible to do. I know its not a good machine, but....... Yes, lots of
good stuff in there folks, thanks, wont disagree with it. But tis not
my environment, dont have a lifetime of skill either. Theres a lot
like us, and esoteric debates about the finer points of lathe design
are well, interesting, yes. Relevant, No.

Still trying to "see" the lathe in 3-dimensions, see how they all
interact. Always was crap at geometry.

Sorry if I have stepped on anyone's toes. Have found it to be like
this in most fields, same in amateur radio, my other passion.. Theres
a lot of assumed knowledge that the newcomer with a non trade
background would not understand. And I went back to trade school to
learn about all this, but somehow the replies here sometimes
are....not in any language I can understand.

So, another question - what came first, the lathe or the precision
level needed to set it up? If it was the lathe first (I got a drawing
of a tree branch one in a book) then how did they set it up? - before
precision levels were invented.

So saying all that, it was a good read, worthy of the bandwidth it
used. Thank you to all for replying.

Andrew VK3BFA.

On Jun 23, 12:36*am, "Ed Huntress" wrote:
"Andrew VK3BFA" wrote in message



You're getting the voices of a lot of experience in this thread, and I don't
have that kind of experience, but you're asking some general questions here
to which I may be able to contribute.



Thank you Ed - I will re-read the sections you mentioned. And I mean
absolutely no offense to those here who are obvious masters of the
craft. I was hoping to learn these things at trade school, but when I
asked, was told it was a machine setters job and they didn't teach it.
I was ****ed at this, I wanted to be able to set up my own one at
home......(and am still bloody trying, g)

So, I aint got a machinists level - and am not buying any new tools at
the moment. I will think about this, and figure out how to do it.

Andrew VK3BFA.

On Wed, 22 Jun 2011 08:16:59 -0700 (PDT), Andrew VK3BFA
wrote:

On Jun 23, 12:36*am, "Ed Huntress" wrote:
"Andrew VK3BFA" wrote in message



You're getting the voices of a lot of experience in this thread, and I don't
have that kind of experience, but you're asking some general questions here
to which I may be able to contribute.



Thank you Ed - I will re-read the sections you mentioned. And I mean
absolutely no offense to those here who are obvious masters of the
craft. I was hoping to learn these things at trade school, but when I
asked, was told it was a machine setters job and they didn't teach it.
I was ****ed at this, I wanted to be able to set up my own one at
home......(and am still bloody trying, g)

So, I aint got a machinists level - and am not buying any new tools at
the moment. I will think about this, and figure out how to do it.

Andrew VK3BFA.

I'd do "rollie's dad's method". No level needed.

Learn to both turn between centers and with tailstock and chuck. Both
have their place.

Ed mentioned laps. I often use a file. Cuts faster and may not be for
work to 2 tenths accuracy. But works great if you got 1 thou taper or
you're trying to get to a light press fit.

I see you're learning to appreciate fine lathes.

Karl

On Jun 22, 1:13*pm, Karl Townsend
wrote:
On Wed, 22 Jun 2011 08:16:59 -0700 (PDT), Andrew VK3BFA
...
Ed mentioned laps. I often use a file. Cuts faster and may not be for
work to 2 tenths accuracy. But works great *if you got 1 thou taper or
you're trying to get to a light press fit.
...
Karl-

Same here. If the workpiece is springy I cut short sections to a
thousandths or so over and blend them all with a single-cut file. I
can also cut a very slight taper for a press fit this way.

Waaay back when, machinists turned metal with hand-held chisels to a
caliper fit, as woodworkers still do. A twisted or even crooked lathe
bed didn't matter.

jsw

On Jun 23, 1:58*am, "Harold & Susan Vordos" wrote:
"Jim Wilkins" wrote in message
...
I might have a few suggestions (or not) if I knew the exact problem you
faced. * Virtually *everything* makes a difference---tool type, rake angle,
feed rate, surface speed, you name it.

Given a perfect world, you'd run the material through a centerless grinder
and enjoy wonderful success.

Harold

Thanks. I make parts either for myself or for electrical engineers who
will gladly take whatever they get without checking dimensions, so I
don't have an unsolved problem. I was asking for general hints to help
people deal with cheap import or old worn US machines.

jsw

On Jun 23, 11:39*am, Jim Wilkins wrote:
On Jun 22, 10:36*am, "Ed Huntress" wrote:

...
http://www.bluechipmachineshop.com/books/SB_H3.pdf
Ed Huntress

Thanks a lot, Ed.

I rechecked my lathe with a South Bend level as shown in the booklet
and one of these:http://www.penntoolco.com/catalog/pr...ategoryID=4511
which is several times as sensitive.

My VIS level may not be exactly centered. I bought it cheap, broken in
shipping, along with a replacement vial the shipper sent. If anyone
asks it's an instrument that always shows the direction to my home
planet.

jsw

Checking the level - measure in one plane, swing the level 180
degrees, should be same reading.

Andrew VK3BFA.

On Jun 23, 1:43*pm, "DoN. Nichols" wrote:
On 2011-06-22, Andrew VK3BFA wrote:

* * * * [ ... ]

things, but not getting the machine time to get competent. So, I ask.
Hence my question - whats better to align between, centres or chuck
and centre?

* * * * Actually -- you don't want the center involved at all at first.
It is good for turning long flexible workpieces, but it confuses the
issue with alignment.

* * * * So:

1) * * *Level the bed with a precision level (to take the bed twist
* * * * out of the equation).

2) * * *Chuck a beefy piece of stock in the chuck alone -- free length
* * * * no longer than say four or six times the diameter. *And hope
* * * * that the jaws of the chuck are not worn bell-mouthed, which will
* * * * make things more difficult.

3) * * *Turn down the middle of this enough to allow you to do a final
* * * * turn of just the ends with a light cut, and measure the results
* * * * with a micrometer.

* * * * There are precision bars with a Morse taper to fit the headstock
* * * * spindle and you measure this with an indicator in the carriage.
* * * * But these are quite expensive -- it is cheaper to turn the
* * * * two-collar bar in the previous paragraph. *It does not even need
* * * * to start out with a good finish -- you're making surfaces
* * * * centered around the axis with your turning.

4) * * *If the two ends measure the same, this part is done.

* * * * If not -- then the mounting of the headstock to the bed has a
* * * * twist in it (not the bed has a twist -- you eliminated that with
* * * * the precision level). One end of the headstock points to the
* * * * front and the other end points to the back, and this needs to be
* * * * fixed before you attempt anything else.

* * * * Some lathes have setscrews which push on the headstock at the
* * * * front and the rear to adjust the alignment. *These are easy to
* * * * fix.

* * * * Other lathes have the V-ways extending under the headstock, and
* * * * used for the alignment. *Probably, the headstock was first
* * * * mounted to the ways, and then bored for bearing placement to
* * * * assure that the spindle is parallel to the ways. *If you have
* * * * parallelism problems with this type (probably a different
* * * * headstock mounted on the old ways), you'll have to work with
* * * * very fine shim stock to bring it in to alignment. *Or do some
* * * * precision scraping. *Or something else serious.

5) * * *Once the lathe is turning with no taper in the chuck, you then
* * * * adjust the tailstock offset so a bar turned between centers has
* * * * no taper. *(You really don't want to do from chuck to tailstock
* * * * center, as this will bend the workpiece if the center adjustment
* * * * is not quite right.

* * * * Note that tailstock center height on a good *new* lathe is a
* * * * little *above* headstock center height. *(maybe 0.0005" or so).
* * * * This is so as the tailstock wears through a long life, the
* * * * tailstock center height gets better for quite a while before it
* * * * starts getting worse.

* * * * [ ... ]

Still trying to "see" the lathe in 3-dimensions, see how they all
interact. Always was crap at geometry.

* * * * That is a handicap in the world of machining. *Both the number
part of geometry (working with angles and sines for setting precise
angles) and the visualizing how things interact.

* * * * [ ... ]

So, another question - what came first, the lathe or the precision
level needed to set it up? If it was the lathe first (I got a drawing
of a tree branch one in a book) then how did they set it up? - before
precision levels were invented.

* * * * Well ... the bent tree branch one was not a precision lathe.
The cutting tool was not guided by the machine -- it only provided some
form of rest, and the tool was guided purely by the operator's hands.
(And the workpiece material was wood, after all. :-)

* * * * I would say that the precision level came into being somewhere
along the progression from the bent branch powered wood lathe to the
precision industrial machines -- and its presence made it easier to set
up a lathe once it was moved from the factory to the machine shop where
it was expected to spend its life. *Before that, machines were mostly
built where they were going to be used, so during the construction
errors wre tuned out.

* * * * This is my take on it all.

* * * * Good Luck,
* * * * * * * * DoN.

--
* * * * * * * * * Remove oil spill source from e-mail
*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 ---

Hi Don - long time no hear. Granted all of the above, still need a
precision level. As soon as I figure out how to do it, I will give it
a try.

Made a test bar at school, measured accurate to 2 microns. (yeh, pure
chutzpah) as my reference point.
Stuck dead centres in both ends, with a dial gauge, checked them for
concentricity. (replaced one) Butted em up close for a loose pre-fit.
(if the whole thing looks like getting good, will use the finger
indicator for greater resolution) Also checked for any devaition or
runout in the headstock shaft - its accessible - was spot on. So the
headstock is probably aligned // with the bed.
the supplied MT3 dead centre at the headstock was crap - bought a new
one. Much better. The tailstock - always been problematical in that
under load it would spin the MT2 tapered shaft. Finally fixed that by
blueing the bore against a known good MT2 plug, then setting up the
dead centre(and the live centre) on the cylindrical grinder and
cleaning up the original supposedly MT2 taper - blueing it till it was
a good, even fit. it was out heaps - much better now, doesnt spin.
Checked // alignment in tailstock by measuring run out on the edge of
a live centre. Crude, I know - but at least an indicator of no major
stuffups. But now the tailstock ram thrashes around as the grub screw
(cheese, made of) locating it is too bloody small for the job...makes
drilling a bit difficult.
So, I do know a bit about machining, its tying it all together -
without a bloody precision level - and yes, it will still be a crap
lathe when its fixed, I know that, too much flex to use a
conventional knurler, dont do bit cuts if you want any accuracy - but
I want it to be better than it damm well is at the moment. And if I
totally stuff it up, it doesn't really worry me, I will by then know
enuff to be able to go out and appraise a used lathe. Dint know
anything before I started all this. Thanks fellas, a lot of knowledge
here.

Andrew VK3BFA.

On Jun 23, 3:26*pm, "Wild_Bill" wrote:
Nearly everyone has commented about using a level. A level is a helpful
universal tool for checking numerous machines (typically large machines).

I sure as hell wouldn't rely on a precision level to check my 7x14
mini-lathe.

A single machine can be checked with gages.. some which may need to be
fabricated for a particular machine, and measuring instruments.

A *calibrated bar* was mentioned, but wasn't described.. which could be one
of several different bars.

I made it at school while learning about cylindrical grinders which
lead to tapers which....its // enuff for setup this lathe...
they had to get specail instruments out of locked cupboards to measure
it accurately enough. (Yeh, I know - too many other variables ever to
get the same reading again....)

And yes, what you described is pretty much the way I was doing it
anyway - thanks, was wondering if I was totally nuts.

Yes, when I know what its doing, you can plug that into your final
cuts - fine by me, got taught about that, using the big machines at
school - whats the actual cut rather than what did you dial up? took
me personally a while, even getting used to using micrometers was a
new skill to be learnt.But I think my lathe, its capable of doing
better than what it is doing now, if I can check and fix as much as
possible, it will be progress.

Andrew VK3BFA.


Andrew VK3BFA.


WB
.........

"Andrew VK3BFA" wrote in message

...

Hi Karl,
thanks - to all - lots of information to assimilate, sort out,
examine, *- . I have used 2 sorts of lathes - my Chinese one at home,
the big industrial machines at school. I can work to tolerance on the
school ones, I cant do it at home. I have learnt how to do a lot of
things, but not getting the machine time to get competent. So, I ask.
Hence my question - whats better to align between, centres or chuck
and centre? Because the way it is is total crap - very limited, and
horrible to do. I know its not a good machine, but....... Yes, lots of
good stuff in there folks, thanks, wont disagree with it. But tis not
my environment, dont have a lifetime of skill either. Theres a lot
like us, and esoteric debates about the finer points of lathe design
are well, interesting, yes. Relevant, No.

Still trying to "see" the lathe in 3-dimensions, see how they all
interact. Always was crap at geometry.

Sorry if I have stepped on anyone's toes. Have found it to be like
this in most fields, same in amateur radio, my other passion.. Theres
a lot of assumed knowledge that the newcomer with a non trade
background would not understand. And I went back to trade school to
learn about all this, but somehow the replies here sometimes
are....not in any language I can understand.

So, another question - what came first, the lathe or the precision
level needed to set it up? If it was the lathe first (I got a drawing
of a tree branch one in a book) then how did they set it up? - before
precision levels were invented.

So saying all that, it was a good read, worthy of the bandwidth it
used. Thank you to all for replying.

Andrew VK3BFA.

On Jun 24, 9:34*am, Andrew VK3BFA wrote:
On Jun 23, 11:39*am, Jim Wilkins wrote:
...
My VIS level may not be exactly centered. I bought it cheap, broken in
shipping, along with a replacement vial the shipper sent. ...
jsw

Checking the level - measure in one plane, swing the level 180
degrees, should be same reading.

Andrew VK3BFA.

Doing that with a level sensitive to 0.0005" in 10" isn't easy. The
test surface has to be nearly level and finely adjustable, and not
shift when I stand anywhere near it or add the weight of the level..

The vial in those is glued with plaster into a pivoting brass block
with an adjustment screw. The block bottomed out against a plate on
one end, which may be what's supposed to happen. I couldn't keep the
surface plate level enough to check exact centering.

jsw

Jim Wilkins fired this volley in news:2fc04650-7e3b-
:

Doing that with a level sensitive to 0.0005" in 10" isn't easy.

Nope, but using fine wire placed carefully the same distance from each
end while testing is better than flat shims. A flat shim bears only on
one edge when slid under a tilted level.

My surface plate has adjustable legs, and although the adjustment thread
is coarse, I have no trouble getting it level to within a half-thou per
foot. Just gentle "taps" on the adjusting wrench results in almost
imperceptible movement of the screw, but noticably moves the plate.

Somehow, my concrete slab doesn't tend to tilt when I walk around near
the surface plate.

LLoyd

I admire you taking on a new frontier/challenge, much different from your
usual background, with a strong desire to learn more and gain confidence in
the new quest.

IIRC, you bought a 9x20 lathe or a similar model a while ago, and began
taking courses to familiarize yourself with metalworking machine practices.

The present day low cost machines are often referred to as a kit.. it
looky-like a real machine, but they all have room for improvement.
The 9x20 models have weak hold-downs for the compound/top slide which really
need to be addressed, as there is a lot of flex/deflection in the original
design.
I forget if you've already corrected that part, but it's the main flaw in an
otherwise fairly decent, versatile benchtop machine.

Much of the other issues are smaller, and some disassembly, cleaning,
deburring and adjustments are generally very much worthwhile.
A variable speed motor is another major improvement for most lathes.

The loose tailstock ram and some other small parts/fasteners typically
require replacement. I made new/better fitting small pieces for each of my
machines.

You're well on your way to attaining a full understanding of the machine's
capabilities and what's required of the operator to easily (more
conveiniently) attain the best results.

Much of the accuracy obtained from any machine is the operator's input.

Nearly any old lathe is much better than a file, hacksaw and drill motor.

--
WB
..........


"Andrew VK3BFA" wrote in message
...


A *calibrated bar* was mentioned, but wasn't described.. which could be
one
of several different bars.

I made it at school while learning about cylindrical grinders which
lead to tapers which....its // enuff for setup this lathe...
they had to get specail instruments out of locked cupboards to measure
it accurately enough. (Yeh, I know - too many other variables ever to
get the same reading again....)

And yes, what you described is pretty much the way I was doing it
anyway - thanks, was wondering if I was totally nuts.

Yes, when I know what its doing, you can plug that into your final
cuts - fine by me, got taught about that, using the big machines at
school - whats the actual cut rather than what did you dial up? took
me personally a while, even getting used to using micrometers was a
new skill to be learnt.But I think my lathe, its capable of doing
better than what it is doing now, if I can check and fix as much as
possible, it will be progress.

Andrew VK3BFA.

On 2011-06-24, Andrew VK3BFA wrote:
On Jun 23, 11:39*am, Jim Wilkins wrote:
On Jun 22, 10:36*am, "Ed Huntress" wrote:

...
http://www.bluechipmachineshop.com/books/SB_H3.pdf
Ed Huntress

Thanks a lot, Ed.

I rechecked my lathe with a South Bend level as shown in the booklet
and one of these:http://www.penntoolco.com/catalog/pr...ategoryID=4511
which is several times as sensitive.

My VIS level may not be exactly centered. I bought it cheap, broken in
shipping, along with a replacement vial the shipper sent. If anyone
asks it's an instrument that always shows the direction to my home
planet.

jsw

Checking the level - measure in one plane, swing the level 180
degrees, should be same reading.

And -- even if it is asymmetrical as described, just use it
pointed the same way for all cross measurements. No, it won't be
precisely level -- but it will be precisely the same angle, which is
good enough for the purpose.

I don't know about the VIS, but the Starrett "Mater Precision
Level" which I have has provisions for adjusting it os it is truly
consistent.

Enjoy,
DoN.

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