I talked to Clausing today. One question I had was how much of a cut
the lathe ought to be able to handle without chattering. The guy I
talked to didn't recall such a spec. Later, I asked if there was spec
on spindle runout et al, and he said that there was a sheet that gave
that information, which he was happy to fax to me, and did.

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Joe Gwinn

"Joseph Gwinn" wrote in message
...
I talked to Clausing today. One question I had was how much of a cut
the lathe ought to be able to handle without chattering. The guy I
talked to didn't recall such a spec. Later, I asked if there was spec
on spindle runout et al, and he said that there was a sheet that gave
that information, which he was happy to fax to me, and did.

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive for
the 5900-series lathes. This from a Clausing brochure I have of unknown
vintage.

In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
[snip]

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive for
the 5900-series lathes. This from a Clausing brochure I have of unknown
vintage.

That agrees with the scales on the control wheel, but there is a hard
stop at 1900 rpm. Thus my question.

Joe Gwinn

Joe,

Don't believe that dial...

When I rebuilt mine I checked the speeds with a tach...
In direct drive I got 300 not the 360 listed on the dial.
And at the top end I got 2150 not the 2000 listed on the dial.
Not many of the speeds on the dial matched EXACTLY what the tach said, but
in truth it's plenty close for the "4 x D calc in your mind" numbers.

Sorry to hear you have chatter on heavy cuts, I was just blasting through
some 4 inch cast iron wheels in back gear taking nice 0.100 cuts, and yeah I
know that aint CRS but...

I also did a couple of axels out of some .750 drill rod I had kicking around
and a fine finish cut of .005 at the slowest longitidunal speed came out
like glass.. :-)))

--.- Dave

..
"Joseph Gwinn" wrote in message
...
I talked to Clausing today. One question I had was how much of a cut
the lathe ought to be able to handle without chattering. The guy I
talked to didn't recall such a spec. Later, I asked if there was spec
on spindle runout et al, and he said that there was a sheet that gave
that information, which he was happy to fax to me, and did.

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Joe Gwinn

In article ,
"Dave August" wrote:

Joe,

Don't believe that dial...

I don't. The Clausing manual suggests using a rpm meter to set the
speeds (by adjusting the cone nut on the lower VS pulley). If no meter,
just set it so the belt comes to the top of the flange. This is what I
have been doing.

The reason to ask is to know what range I should be able to achieve, to
know when I have achieved what the machine was designed to achieve.


When I rebuilt mine I checked the speeds with a tach...
In direct drive I got 300 not the 360 listed on the dial.
And at the top end I got 2150 not the 2000 listed on the dial.
Not many of the speeds on the dial matched EXACTLY what the tach said, but
in truth it's plenty close for the "4 x D calc in your mind" numbers.

Yep.


Sorry to hear you have chatter on heavy cuts,

Heavy cuts per se don't seem to be the problem, but cutting off is.

It's an old machine, and every discovery seems to yield substantial
improvement, but eventually diminishing returns will set in.



I was just blasting through
some 4 inch cast iron wheels in back gear taking nice 0.100 cuts, and yeah I
know that ain't CRS but...

I bet cast iron would not be a problem, based on how brass worked.


I also did a couple of axels out of some .750 drill rod I had kicking around
and a fine finish cut of .005 at the slowest longitidunal speed came out
like glass.. :-)))

This I can probably do already, as I have gotten some mirror finishes.


Joe

.
"Joseph Gwinn" wrote in message
...
I talked to Clausing today. One question I had was how much of a cut
the lathe ought to be able to handle without chattering. The guy I
talked to didn't recall such a spec. Later, I asked if there was spec
on spindle runout et al, and he said that there was a sheet that gave
that information, which he was happy to fax to me, and did.

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Joe Gwinn

I haven't had any issues with cutoff work.

What's your tool post?

What kind of cutoff tool?

Have you tried a test with the cutoff tool mounted directly to the cross
slid and not on the compound, that's what I had to do on the "import"...

--.- Dave

Sorry to hear you have chatter on heavy cuts,

Heavy cuts per se don't seem to be the problem, but cutting off is.

Joseph Gwinn wrote:

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

Could you scan that and email it to me?


wess ignorethis
At ignorethisalso
Wess.mdns.org

Joseph Gwinn wrote:

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".


The Leblond at work has about 0.001 backlash. I like the feel of that
machine.

Wes

Joseph Gwinn wrote:
the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

Aha! Well, the test is a darn serious cut, except for the feed
per turn. That can cause work hardening, so you need some
REALLY mild steel to prevent problems there. I'd use the
slowest direct-drive speed, and maybe cut the depth of cut down
to .1" or so. 5" work overhang with no support is really
pushing it, it is something you'd rarely do in normal practice,
but it will tell you if there is something loose! I'd make
especially sure the tool is well supported, the overhang from
the toolpost should be an absolute minimum, and the compound
should be in the center of it's travel for the best support.
If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

This is not the cause of chatter, and is expected on a used machine.

Jon

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
[snip]

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive for
the 5900-series lathes. This from a Clausing brochure I have of unknown
vintage.

That agrees with the scales on the control wheel, but there is a hard
stop at 1900 rpm. Thus my question.

I've not delved into the speed control much, but if memory serves there is a
roll pin that acts as the hard stop. Can the speed control hub be rotated
to adjust the setting at which the stop becomes effective?

In article ,
"Dave August" wrote:

I haven't had any issues with cutoff work.

What's your tool post?

Aloris BXA bolted (5/8-20) to the the T-slot in the standard-issue
compound.


What kind of cutoff tool?

BXA-7 and also SGIH 19-2 blade held in a Dorian BXA 7-71C.

I get chatter even when the SGIH blade et al are mounted upsidedown and
the lather run in reverse, which eliminates self-feeding as a cause.

Oddly, the upsidedown SGIH works fine when the work is held in a collet,
but chatters if the work is in a 3-jaw chuck. The chuck does not appear
to be worn, but its length implies that the cutting point is an added 5"
or 6" farther from the spindle bearings.


Have you tried a test with the cutoff tool mounted directly to the cross
slide and not on the compound, that's what I had to do on the "import"...

This I have not tried, and would require some fabrication. An
alternative would be to over-tighten the gibs of the compound. But, the
lathe ought to be able to make such cutoffs without bypassing the
compound, which is why I have kept on trying.

Gunnar suggested locking the lower gibs and using only the compound to
advance the blade. I did this some time ago and it had no effect, but
it may be time to repeat the exercise.


My suspicion is focused on the cross-slide slideway and gibs, as when I
put a 5-foot long 1" bar in the boring bar holder perpendicular to the
bed ways and tug up and down on the bar, which is centered in the holder
so the bar's own weight balances out. I feel motion only in the
cross-slide gap when I tug on the bar.

The problem is that this is a very severe test, and I don't know how
much motion is to be expected for a lathe of this size and heft, even if
it were new.


Clausing has also suggested that I tighten the spindle adjustment nut by
1/4 turn. This is today's project. I may have to fabricate a
radial-pin spanner wrench to do this.


Joe Gwinn

In article ,
Wes wrote:

Joseph Gwinn wrote:

It turned out to be the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

Could you scan that and email it to me?

Not easily at present (no scanner), but Clausing will fax it to you on
request. Their phone number is 574-533-0371.


I can also extract and summarize the relevant text. What's lost are the
little diagrams showing what is being measured, so I've added some
clarifying words.

1. Bed Level, transverse direction: all readings (across bed) to be
within 0.0005" in 12 inches.

2. Bed Level, longitudinal direction: Maximum reading along bed of
0.001" in 12 inches.

3. Spindle Center Runout: zero to 0.0008" total indicator runout, with
indicator resting on a dead center mounted in the spindle.

4. Spindle Nose Runout: 0 to 0.0003" on the spindle's L-00 taper.

5. Spindle Taper Runout: Total indicator runout in two places, right
at the spindle nose, and at the end of a 12" test bar: 0 to 0.0003" and
0 to 0.0006" respectively. The test bar appears to have a MT 4.5 taper
in one end, as there is no mention of using the MT3 spindle sleeve.

6. Headstock Alignment, vertical: Max height deviation at end of 12"
bar is 0 to +0.0005". Probably uses same test bar as test #5.

7. Tailstock Alignment, vertical: Max height deviation at end of 12"
bar with spindle fully extended is 0 to +0.0008". Test bar will need a
MT3 taper.

8. Headstock Alignment, horizontal: At the end of a 12" test bar, 0 to
+/- 0.0003".

9. Tailstock Spindle Alignment, horizontal: At the end of the fully
extended spindle, 0 to 0.0005", measured from the front of the lathe.

10. Tailstock Taper Alignment, horizontal: At the end of a 12" test
bar, 0 to +/- 0.0005". Spindle shown as fully retracted, and perhaps
it's clamped as well.

11. Tailstock Taper Alignment, vertical: High at the end of a 12" test
bar, 0 to +0.001". Spindle shown as fully retracted, and perhaps it's
clamped as well.

12. Cross Slide Alignment: This is a combined test. Apparently, one
first faces off (machines) the faceplate, and then does some indicator
tests. The faceplate is allowed to be concave only, and the deviation
from flat cannot exceed 0 to 0.0005" when the cross slide is moved,
scanning the indicator along a diameter. The runout due to rotation of
the faceplate also cannot exceed 0 to 0.0005".

13. Lathe Must Turn Round With Work Mounted in Chuck: Turn a test
piece, and measure diameter with a micrometer. No pair of measured
diameters can differ by more than 0.0003". Actually, it's possible to
pass this test and yet not be round. A better test is to turn
something, and then measure it between a V-block and a dial indicator.
But the multiple-diameters test will catch most of the irregular shapes
a lathe is likely to make.

14. Running test for smooth operation: The test specifies that the
lathe must be able to cut a 1.5" diameter bar of CRS with 5" protruding
from the 3-jaw chuck (and no tailstock use), running at "high speed"
while taking a 0.125" depth of cut (0.25" diameter reduction) and
feeding 0.0026" per turn, without chatter. High speed is not defined,
but surely precludes use of the back gear for this test.

15. Back Lash on Cross Feed Screw: 0.004" max.


Joe Gwinn

In article ,
Wes wrote:

Joseph Gwinn wrote:

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".


The Leblond at work has about 0.001 backlash. I like the feel of that
machine.

Errr. May I ask, what does this lathe weigh?

Joe Gwinn

Jeez,

I use the same (well mines a knock off but..) tool post and blades...

Crossslide only, Understood that it "should" work on the compound, since
mine "does" work... Just trying to come up with a simple test to eliminate
things...

Clausing might be right, time to try the spindle nut test.

Keep us.. "posted".. :-)

--.- ave

"Joseph Gwinn" wrote in message
...
In article ,
"Dave August" wrote:

I haven't had any issues with cutoff work.

What's your tool post?

Aloris BXA bolted (5/8-20) to the the T-slot in the standard-issue
compound.


What kind of cutoff tool?

BXA-7 and also SGIH 19-2 blade held in a Dorian BXA 7-71C.

I get chatter even when the SGIH blade et al are mounted upsidedown and
the lather run in reverse, which eliminates self-feeding as a cause.

Oddly, the upsidedown SGIH works fine when the work is held in a collet,
but chatters if the work is in a 3-jaw chuck. The chuck does not appear
to be worn, but its length implies that the cutting point is an added 5"
or 6" farther from the spindle bearings.


Have you tried a test with the cutoff tool mounted directly to the cross
slide and not on the compound, that's what I had to do on the "import"...

This I have not tried, and would require some fabrication. An
alternative would be to over-tighten the gibs of the compound. But, the
lathe ought to be able to make such cutoffs without bypassing the
compound, which is why I have kept on trying.

Gunnar suggested locking the lower gibs and using only the compound to
advance the blade. I did this some time ago and it had no effect, but
it may be time to repeat the exercise.


My suspicion is focused on the cross-slide slideway and gibs, as when I
put a 5-foot long 1" bar in the boring bar holder perpendicular to the
bed ways and tug up and down on the bar, which is centered in the holder
so the bar's own weight balances out. I feel motion only in the
cross-slide gap when I tug on the bar.

The problem is that this is a very severe test, and I don't know how
much motion is to be expected for a lathe of this size and heft, even if
it were new.


Clausing has also suggested that I tighten the spindle adjustment nut by
1/4 turn. This is today's project. I may have to fabricate a
radial-pin spanner wrench to do this.


Joe Gwinn

In article ,
Jon Elson wrote:

Joseph Gwinn wrote:
the "Clausing Test Report, 5900-series Lathe", a
one-page form that was filled out and provided to the purchaser of each
lathe. There are 15 tests listed. Most are for various kinds of
alignment and runout, and are all less than 0.001" both near the
headstock or tailstock as appropriate, and also at the end of a 12" bar
held in one or the other.

As for runout, on hearing my long sad chatter stories, Clausing
suggested tightening the spindle bearing take-up nut by 1/4 turn, even
though the spindle passes the spein-spindle-by-hand test.

The next to last test, the "Running test for smooth operation", is the
answer to my original question. The test specifies that the lathe must
be able to cut a 1.5" diameter bar of CRS with 5" protruding from the
3-jaw chuck (and no tailstock use), running at "high speed" while taking
a 0.125" depth of cut (0.25" diameter reduction) and feeding 0.0026" per
turn, without chatter.

What is "high speed"? If their tools were HSS, the surface speed should
be in the range 80-120 fpm for optimum performance. To achieve 120 fpm
in a 1.5" round bar, one must spin the bar at 306 rpm, which is above
the fastest backgear speed and below the slowest normal speed, so this
seems unlikely.

Aha! Well, the test is a darn serious cut, except for the feed
per turn. That can cause work hardening, so you need some
REALLY mild steel to prevent problems there. I'd use the
slowest direct-drive speed, and maybe cut the depth of cut down
to 0.1" or so. 5" work overhang with no support is really
pushing it, it is something you'd rarely do in normal practice,
but it will tell you if there is something loose! I'd make
especially sure the tool is well supported, the overhang from
the toolpost should be an absolute minimum, and the compound
should be in the center of its travel for the best support.

I've been using the BXA-16N holder, which is massive.

In any event, I could not cut a 1" steel (1018) bar without chatter at
any direct drive speed at that depth of cut, with the bar (3" sticking
out, not 5") in the 3-jaw chuck.

I did test for bell-mouth of the chuck jaws, by the ball-bearing test
and by chucking a 0.5" drill blank and probing with a 0.001 feeler. No
go.

As discussed in other postings, I think it's time to take Clausing's
advice and tighten the spindle bearing adjustment nut.


If the tools were instead carbide, the optimum speeds are a factor of 5
faster, which puts one at 1,528 rpm, which is at the upper end of the
5914's range (the max being 1900 rpm), which makes sense. This sounds
like smoking blue chip territory for sure. But I will try it. While
standing well to one side.

Also of interest is the cross feed screw backlash, 0.004" max. It was
0.025" on receipt of the lathe, and is now 0.010" after replacement of
the T-Nut (the original screw being retained). The compound slide
backlash also meets this 0.004", after replacement of both screw and
bronze nut; it had been about 0.050".

This is not the cause of chatter, and is expected on a used machine.

Yep.

Joe Gwinn

In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
[snip]

Actually, what is the claimed speed range of the 5914? This must have
been published in a brochure or catalog page somewhere. The scale on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive for
the 5900-series lathes. This from a Clausing brochure I have of unknown
vintage.

That agrees with the scales on the control wheel, but there is a hard
stop at 1900 rpm. Thus my question.

I've not delved into the speed control much, but if memory serves there is a
roll pin that acts as the hard stop. Can the speed control hub be rotated
to adjust the setting at which the stop becomes effective?

Probably, but Clausing probably had a good reason to put the hard stop
where they put it. I'm trying to figure this out before T try to
circumvent it.

Joe Gwinn

In article ,
"Dave August" wrote:

Jeez,

I use the same (well mine's a knock off but..) tool post and blades...

Crossslide only, Understood that it "should" work on the compound, since
mine "does" work... Just trying to come up with a simple test to eliminate
things...

Clausing might be right, time to try the spindle nut test.

I just tightened the spindle bearing adjustment nut. It made a huge
difference. Now that I think about it, the headstock never got warm
after running a while, and it's supposed to get warm but not too hot to
touch.

Joe Gwinn



Keep us.. "posted".. :-)

--.- ave

"Joseph Gwinn" wrote in message
...
In article ,
"Dave August" wrote:

I haven't had any issues with cutoff work.

What's your tool post?

Aloris BXA bolted (5/8-20) to the the T-slot in the standard-issue
compound.


What kind of cutoff tool?

BXA-7 and also SGIH 19-2 blade held in a Dorian BXA 7-71C.

I get chatter even when the SGIH blade et al are mounted upsidedown and
the lather run in reverse, which eliminates self-feeding as a cause.

Oddly, the upsidedown SGIH works fine when the work is held in a collet,
but chatters if the work is in a 3-jaw chuck. The chuck does not appear
to be worn, but its length implies that the cutting point is an added 5"
or 6" farther from the spindle bearings.


Have you tried a test with the cutoff tool mounted directly to the cross
slide and not on the compound, that's what I had to do on the "import"...

This I have not tried, and would require some fabrication. An
alternative would be to over-tighten the gibs of the compound. But, the
lathe ought to be able to make such cutoffs without bypassing the
compound, which is why I have kept on trying.

Gunnar suggested locking the lower gibs and using only the compound to
advance the blade. I did this some time ago and it had no effect, but
it may be time to repeat the exercise.


My suspicion is focused on the cross-slide slideway and gibs, as when I
put a 5-foot long 1" bar in the boring bar holder perpendicular to the
bed ways and tug up and down on the bar, which is centered in the holder
so the bar's own weight balances out. I feel motion only in the
cross-slide gap when I tug on the bar.

The problem is that this is a very severe test, and I don't know how
much motion is to be expected for a lathe of this size and heft, even if
it were new.


Clausing has also suggested that I tighten the spindle adjustment nut by
1/4 turn. This is today's project. I may have to fabricate a
radial-pin spanner wrench to do this.


Joe Gwinn

Ya know I was gonna ask that...

After a days work my spindle and head are pleasantly warm, not hot, just
warm...

And go read my bitch, I just blew my drive again... :-(((

--.- Dave

"Joseph Gwinn" wrote in message
...
In article ,
"Dave August" wrote:

Jeez,

I use the same (well mine's a knock off but..) tool post and blades...

Crossslide only, Understood that it "should" work on the compound,
since
mine "does" work... Just trying to come up with a simple test to
eliminate
things...

Clausing might be right, time to try the spindle nut test.

I just tightened the spindle bearing adjustment nut. It made a huge
difference. Now that I think about it, the headstock never got warm
after running a while, and it's supposed to get warm but not too hot to
touch.

Joe Gwinn



Keep us.. "posted".. :-)

--.- ave

"Joseph Gwinn" wrote in message
...
In article ,
"Dave August" wrote:

I haven't had any issues with cutoff work.

What's your tool post?

Aloris BXA bolted (5/8-20) to the the T-slot in the standard-issue
compound.


What kind of cutoff tool?

BXA-7 and also SGIH 19-2 blade held in a Dorian BXA 7-71C.

I get chatter even when the SGIH blade et al are mounted upsidedown and
the lather run in reverse, which eliminates self-feeding as a cause.

Oddly, the upsidedown SGIH works fine when the work is held in a
collet,
but chatters if the work is in a 3-jaw chuck. The chuck does not
appear
to be worn, but its length implies that the cutting point is an added
5"
or 6" farther from the spindle bearings.


Have you tried a test with the cutoff tool mounted directly to the
cross
slide and not on the compound, that's what I had to do on the
"import"...

This I have not tried, and would require some fabrication. An
alternative would be to over-tighten the gibs of the compound. But,
the
lathe ought to be able to make such cutoffs without bypassing the
compound, which is why I have kept on trying.

Gunnar suggested locking the lower gibs and using only the compound to
advance the blade. I did this some time ago and it had no effect, but
it may be time to repeat the exercise.


My suspicion is focused on the cross-slide slideway and gibs, as when I
put a 5-foot long 1" bar in the boring bar holder perpendicular to the
bed ways and tug up and down on the bar, which is centered in the
holder
so the bar's own weight balances out. I feel motion only in the
cross-slide gap when I tug on the bar.

The problem is that this is a very severe test, and I don't know how
much motion is to be expected for a lathe of this size and heft, even
if
it were new.


Clausing has also suggested that I tighten the spindle adjustment nut
by
1/4 turn. This is today's project. I may have to fabricate a
radial-pin spanner wrench to do this.


Joe Gwinn

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
[snip]

Actually, what is the claimed speed range of the 5914? This must
have
been published in a brochure or catalog page somewhere. The scale
on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel
assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive
for
the 5900-series lathes. This from a Clausing brochure I have of
unknown
vintage.

That agrees with the scales on the control wheel, but there is a hard
stop at 1900 rpm. Thus my question.

I've not delved into the speed control much, but if memory serves there
is a
roll pin that acts as the hard stop. Can the speed control hub be
rotated
to adjust the setting at which the stop becomes effective?

Probably, but Clausing probably had a good reason to put the hard stop
where they put it. I'm trying to figure this out before T try to
circumvent it.

No, I meant that the position of the hard stop may *need* to be adjusted.
I'm not at all certain of that though, so just consider it a thought.

In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Mike Henry" wrote:

"Joseph Gwinn" wrote in message
...
[snip]

Actually, what is the claimed speed range of the 5914? This must
have
been published in a brochure or catalog page somewhere. The scale
on
the variable speed control wheel appears to be wider than the actual
range. For one thing, the scale goes to 2000 rpm, but one hits a
mechanical stop at 1900 rpm. Probably the same control wheel
assembly
was used on multiple lathe models, each with slightly different
gear/pulley ratios, with limit stops adjusted to match.

Clausing claimed 52-280 rpm in back gear and 360-2000 in direct drive
for
the 5900-series lathes. This from a Clausing brochure I have of
unknown
vintage.

That agrees with the scales on the control wheel, but there is a hard
stop at 1900 rpm. Thus my question.

I've not delved into the speed control much, but if memory serves there
is a
roll pin that acts as the hard stop. Can the speed control hub be
rotated
to adjust the setting at which the stop becomes effective?

Probably, but Clausing probably had a good reason to put the hard stop
where they put it. I'm trying to figure this out before I try to
circumvent it.

No, I meant that the position of the hard stop may *need* to be adjusted.
I'm not at all certain of that though, so just consider it a thought.

OK.

Joe Gwinn