|
Posted by Joseph Gwinn on May 6, 2008, 11:38 pm
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> >
>
> [ ... ]
>
> >> > Yep. I wanted a lathe with integral cabinet stand, on the theory that
> >> > it would all fit together better.
> >>
> >> And you got that. (And got rid of the chatter problem with the
> >> new gib. Congratulations.
> >
> > Thanks. I've been reflecting on how I came to the conclusion that the
> > 5914 needed new gibs.
> >
> > The key was the gross tilting of the toolpost, which moved something
> > like a tenth or even an eighth of an inch, and yet nothing broke (except
> > for a tool bit now and then).
> >
> > There is a reason people don't make springs out of cast iron, so the
> > castings could not be bending enough to explain such large deflections.
> > So it had to be the joints and/or slideways. The only joints were
> > firmly bolted (toolpost to slide) or wedged (tool holder to toolpost),
> > and no relative motion could be felt. And the headstock was firmly
> > bolted to the bed.
> >
> > This left the slideways, of which there are three.
> >
> > The first is between the bed ways and the carriage. This originally had
> > ~0.003" wear-induced clearance, reduced to ~0.001" by removal of one
> > 0.002" brass shim from each of the two rear hold-down plates. The
> > carriage is about 12" wide along the bed, so this 0.001" could account
> > for only about 0.001" of the tilt (measured at the end of the 5"
> > overhang). Only ~0.099" to go.
> >
> > The second is the cross-slide dovetail (~2" wide), and the third is the
> > compound dovetail (~1.625" wide). The observed wear (~0.004" in both)
> > would easily explain the observed deflection, given the leverage from
> > the overhang plus the 2:1 amplification in each of the 60-degree
> > dovetails.
>
> And -- your compound has less adjustment range for the gib
> because the dovetail itself is shorter, so the compound would show the
> problems sooner, given equal wear.
It was the narrower dovetail width that matters, more so than the
length. On a narrower dovetail the same amount of wear in thousandths
allows for greater angular motion.
> > And it didn't feel right when I tightened the gibs. The effect on
> > slideway drag was very gradual as I tightened the gibs; one would expect
> > the effect on drag to be far more abrupt. This pointed to misshapen
> > gibs springing under pressure, versus being in pure compression.
>
> Yep! Good diagnostics.
Ya gotta have a feel for feel.
I did another experiment today, this time cutting 1018 steel with the
grooving tool with the flat nose 0.206" wide held upside down in a
toolholder and with the lathe in reverse, and the backgear engaged. I
can cut a wide groove without drama and in almost total silence (aside
for the noise of the gears), but the tool and toolpost rises visibly
under the strain.
Now this is a very severe test, yielding chips about -0.008" thick by
0.200" wide, and involves very large forces, so the toolbit rising is
not a surprise. One has to push pretty hard before the tool starts to
bite with an audible bump, and it then yields the 0.008" thick chip. If
one maintains the pressure, one can make a very long and curly chip.
> [ ... ]
>
> >> > If you are not on Windows, why would this be a problem?
> >>
> >> Because I don't depend on them *always* focusing on Windows
> >> systems, just because they are the easiest target. There have been
> >> experimental attacks which used javascript, or java, and I see lots of
> >> information about security holes in the flash plugins (information from
> >> the CERT mailing list). Anything attacking something other than the
> >> basic native machine language can be made to work on other systems.
> >
> > It's true that everything has vulnerabilities, but as a matter of actual
> > (versus theoretical) risk, once you leave Windows things get pretty
> > quiet, and the expense (dollar cost and time cost and lost opportunity
> > cost) of security soon outweighs the cost of cleaning up the occasional
> > problem.
> >
> > I read in one of the Mac magazines that only 10% or 15% of Mac owners
> > use any kind of add-on anti-virus product, and the unprotected Mac
> > owners are none the worse for it, and have been for years.
> >
> > Unix/Linux users have even less to worry about.
>
> Yes -- though there is a tradeoff to being a user of the most
> numerous unix version -- which I think is now Solaris 10. That makes it
> the next likeliest target.
But it has not happened yet. And while Solaris isn't completely
hack-proof, it's orders of magnitude less vulnerable than Windows.
> > By contrast, an unprotected Windows machine on the web will last a few
> > days at most, and a dialup machine might manage months before getting
> > caught.
>
> An unpatched Windows box, from first connection to the net in a
> college dorm, has an expected mean-time-to-infection significantly less
> than the time needed to download the patches via the net -- even with a
> fast pipe. This is why at least some colleges (those who care about
> security) will not connect a new box to the net until one of their staff
> have come around with a DVD or CD containing all the patches and applied
> them. This at least slows down the infection rate somewhat. :-)
A college dorm has to be some kind of worst case test.
One very large problem in Windows is that one does not have to provide a
password to install most software, while in MacOS and Unix, one does.
This sharply limits the growth rate of viruses as at ever step of the
way, a human is required. This prevention of automation is sufficient
to sharply reduce the prevalence of viruses in non-Windows platforms.
Now, Microsoft is slowly changing Windows so people don't have to run
their software from an administrator account, but this is like turning
the Queen Mary. But it five or ten years it will have been done.
> >> [ ... ]
> >>
> >> >> > I have the gibs adjusted so there is much drag, but the cross-slide
> >> >> > backlash is about 0.020", and the compound slide backlash is about
> >> >> > 0.006".
> >> >>
> >> >> O.K.
> >> >
> >> > I figured out how better to adjust things, and got this down to ~0.003".
> >>
> >> Good!
> >
> > I should say how I did this. It turned out to be simple. There is a
> > black steel collar upon which the dial rotates, the collar being fixed
> > to the screw shaft with a setscrew. Loosen setscrew. Tighten the cone
> > nut (or nylock nut) until the screw shaft binds, then back off just
> > enough that the screw shaft turns freely. Tighten setscrew.
>
> Oh -- the thrust bearing was loose. On the cross-slide of mine,
> the handcrank screws onto the leadscrew and then is locked by a cone
> nut which goes into a countersink in the crank (IIRC). It is easy to
> get this too tight. But it is also easy to tell that this is the source
> of the play by feel. You feel a bit of a "thud" as the bearing play is
> taken up, while the backlash in the actual leadscrew/net interface is
> less sudden. :-)
The hand cranks are woodruff keyed to the screw shafts on the 5914, and
are kept on the screw shaft with a thread and cone nut as well.
> > Before doing this, it helps to disassemble, clean, and lubricate the
> > entire dial assembly, so things can turn freely.
>
> Of course.
Mine turned OK albeit with drag, and I worried that people might not
realize how much better it would work after a cleaning, in particular if
one wants to move the dial to a new zero without disturbing things.
> [ ... ]
> >
> > Someday I'll have the room for a horizontal mill. I keep running into
> > jobs for which it would be perfect. But it sounds like a perfect
> > application for copious flood cooling, if only to control the swarf.
>
> The Nichols horizontal mill takes a lot less space than many,
> and (usually) offers a choice between leadscrew or lever feed through a
> rack-and-pinion drive for the X-axis feed. And -- there are a pair of
> micrometer stops which can be set up to restrict the X-axis travel
> rather precisely. Nice for certain forms of production work.
I've seen pictures, but never met one in person. What do they weigh?
Joe Gwinn
|
|
Posted by DoN. Nichols on May 7, 2008, 10:21 pm
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[ ... ]
>> And -- your compound has less adjustment range for the gib
>> because the dovetail itself is shorter, so the compound would show the
>> problems sooner, given equal wear.
>
> It was the narrower dovetail width that matters, more so than the
> length. On a narrower dovetail the same amount of wear in thousandths
> allows for greater angular motion.
O.K. But you also probably don't have as much adjustment range
in the tapered gib so you can't tune out as much wear as you could in
the cross-slide.
[ ... ]
> I did another experiment today, this time cutting 1018 steel with the
> grooving tool with the flat nose 0.206" wide held upside down in a
> toolholder and with the lathe in reverse, and the backgear engaged. I
> can cut a wide groove without drama and in almost total silence (aside
> for the noise of the gears), but the tool and toolpost rises visibly
> under the strain.
O.K.
> Now this is a very severe test, yielding chips about -0.008" thick by
> 0.200" wide, and involves very large forces, so the toolbit rising is
> not a surprise. One has to push pretty hard before the tool starts to
> bite with an audible bump, and it then yields the 0.008" thick chip. If
> one maintains the pressure, one can make a very long and curly chip.
Yes -- though the long and curly chip when parting can be a
problem, because it can wedge in the groove and result in a broken
parting tool.
[ ... ]
>> > I read in one of the Mac magazines that only 10% or 15% of Mac owners
>> > use any kind of add-on anti-virus product, and the unprotected Mac
>> > owners are none the worse for it, and have been for years.
>> >
>> > Unix/Linux users have even less to worry about.
>>
>> Yes -- though there is a tradeoff to being a user of the most
>> numerous unix version -- which I think is now Solaris 10. That makes it
>> the next likeliest target.
>
> But it has not happened yet. And while Solaris isn't completely
> hack-proof, it's orders of magnitude less vulnerable than Windows.
And I've also turned off quite a few things which I don't need
or want. And, at least in unix systems, it is fairly easy to learn how
to turn things off or on.
>> > By contrast, an unprotected Windows machine on the web will last a few
>> > days at most, and a dialup machine might manage months before getting
>> > caught.
>>
>> An unpatched Windows box, from first connection to the net in a
>> college dorm, has an expected mean-time-to-infection significantly less
>> than the time needed to download the patches via the net -- even with a
>> fast pipe. This is why at least some colleges (those who care about
>> security) will not connect a new box to the net until one of their staff
>> have come around with a DVD or CD containing all the patches and applied
>> them. This at least slows down the infection rate somewhat. :-)
>
> A college dorm has to be some kind of worst case test.
Indeed so. Lots of machines in unskilled hands, tons of
bandwidth, so they can all be attacking each other. :-)
> One very large problem in Windows is that one does not have to provide a
> password to install most software,
And toss in the "have you forgotten your password? Would you
like to set another?" behavior, and ... :-)
> while in MacOS and Unix, one does.
> This sharply limits the growth rate of viruses as at ever step of the
> way, a human is required. This prevention of automation is sufficient
> to sharply reduce the prevalence of viruses in non-Windows platforms.
Indeed so.
> Now, Microsoft is slowly changing Windows so people don't have to run
> their software from an administrator account, but this is like turning
> the Queen Mary. But it five or ten years it will have been done.
If they are still around by then. :-)
[ ... ]
>> Oh -- the thrust bearing was loose. On the cross-slide of mine,
>> the handcrank screws onto the leadscrew and then is locked by a cone
>> nut which goes into a countersink in the crank (IIRC). It is easy to
>> get this too tight. But it is also easy to tell that this is the source
>> of the play by feel. You feel a bit of a "thud" as the bearing play is
>> taken up, while the backlash in the actual leadscrew/net interface is
>> less sudden. :-)
>
> The hand cranks are woodruff keyed to the screw shafts on the 5914, and
> are kept on the screw shaft with a thread and cone nut as well.
I had to go back to the manual to make sure that I had
remembered it properly. It is a threaded collar of fairly small
diameter with a step towards the crank on which the dial slips and
rotates when the thumbscrew is loose. And yes, the collar *does* thread
onto the end of the shaft, with a nut which locks against that, and then
the crank screws on. But there is not the cone nut which I thought that
I remembered.
>> > Before doing this, it helps to disassemble, clean, and lubricate the
>> > entire dial assembly, so things can turn freely.
>>
>> Of course.
>
> Mine turned OK albeit with drag, and I worried that people might not
> realize how much better it would work after a cleaning, in particular if
> one wants to move the dial to a new zero without disturbing things.
Indeed -- and the drag for the crank actually helps avoid
disturbing the crank position while re-positioning the dial.
[ ... ]
>> The Nichols horizontal mill takes a lot less space than many,
>> and (usually) offers a choice between leadscrew or lever feed through a
>> rack-and-pinion drive for the X-axis feed. And -- there are a pair of
>> micrometer stops which can be set up to restrict the X-axis travel
>> rather precisely. Nice for certain forms of production work.
>
> I've seen pictures, but never met one in person. What do they weigh?
About 1100 pounds. It comes with a gearhead three-phase motor,
so you would need a VFD or a rotary converter to run it. I can't see
swapping in any other motor. Lots of cast iron in the base, the knee,
and the table. the head is mounted to the side of the column via a
dovetail, and there is a lever connected to a rack-and-quadrant gear
arrangement to move the head up and down. There is a lever between the
motor and the head pivoted in the middle of the column, so when the
head goes up, the motor goes down, maintaining a constant spacing and
thus constant belt tension. The really old ones have 1" shafts on both
the motor and the quill, and the pulleys are double groove per speed,
two speeds, and to get the other two speeds, you had to interchange the
motor pulley with the spindle pulley.
The later ones had a single belt instead of double, and five
steps so you had a pretty good range of speeds. I've adapted the later
pulleys to mine -- but I don't have the larger bore for a bigger drawbar
which the newer ones had. I had to make my own mounting ring for the
vertical head. But mine was a *very* old one. Both the horizontal head
and the vertical adaptor use 40-taper NTMB holders and arbors.
Enjoy,
DoN.
--
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
|
|
Posted by Joseph Gwinn on May 7, 2008, 11:38 pm
Please log in for more thread options
>
> [ ... ]
>
> >> And -- your compound has less adjustment range for the gib
> >> because the dovetail itself is shorter, so the compound would show the
> >> problems sooner, given equal wear.
> >
> > It was the narrower dovetail width that matters, more so than the
> > length. On a narrower dovetail the same amount of wear in thousandths
> > allows for greater angular motion.
>
> O.K. But you also probably don't have as much adjustment range
> in the tapered gib so you can't tune out as much wear as you could in
> the cross-slide.
I don't understand. Both gibs are tapered.
> > Now this is a very severe test, yielding chips about -0.008" thick by
> > 0.200" wide, and involves very large forces, so the toolbit rising is
> > not a surprise. One has to push pretty hard before the tool starts to
> > bite with an audible bump, and it then yields the 0.008" thick chip. If
> > one maintains the pressure, one can make a very long and curly chip.
>
> Yes -- though the long and curly chip when parting can be a
> problem, because it can wedge in the groove and result in a broken
> parting tool.
But the tool is upsidedown, so that won't happen. Well, not often.
> [ ... ]
>
> >> > I read in one of the Mac magazines that only 10% or 15% of Mac owners
> >> > use any kind of add-on anti-virus product, and the unprotected Mac
> >> > owners are none the worse for it, and have been for years.
> >> >
> >> > Unix/Linux users have even less to worry about.
> >>
> >> Yes -- though there is a tradeoff to being a user of the most
> >> numerous unix version -- which I think is now Solaris 10. That makes it
> >> the next likeliest target.
> >
> > But it has not happened yet. And while Solaris isn't completely
> > hack-proof, it's orders of magnitude less vulnerable than Windows.
>
> And I've also turned off quite a few things which I don't need
> or want. And, at least in unix systems, it is fairly easy to learn how
> to turn things off or on.
True enough.
> >> > By contrast, an unprotected Windows machine on the web will last a few
> >> > days at most, and a dialup machine might manage months before getting
> >> > caught.
> >>
> >> An unpatched Windows box, from first connection to the net in a
> >> college dorm, has an expected mean-time-to-infection significantly less
> >> than the time needed to download the patches via the net -- even with a
> >> fast pipe. This is why at least some colleges (those who care about
> >> security) will not connect a new box to the net until one of their staff
> >> have come around with a DVD or CD containing all the patches and applied
> >> them. This at least slows down the infection rate somewhat. :-)
> >
> > A college dorm has to be some kind of worst case test.
>
> Indeed so. Lots of machines in unskilled hands, tons of
> bandwidth, so they can all be attacking each other. :-)
And absolutely no common sense about which websites are likely to be a
problem.
> > One very large problem in Windows is that one does not have to provide a
> > password to install most software,
>
> And toss in the "have you forgotten your password? Would you
> like to set another?" behavior, and ... :-)
>
> > while in MacOS and Unix, one does.
> > This sharply limits the growth rate of viruses as at ever step of the
> > way, a human is required. This prevention of automation is sufficient
> > to sharply reduce the prevalence of viruses in non-Windows platforms.
>
> Indeed so.
>
> > Now, Microsoft is slowly changing Windows so people don't have to run
> > their software from an administrator account, but this is like turning
> > the Queen Mary. But it five or ten years it will have been done.
>
> If they are still around by then. :-)
Oh, they will for sure, It's damn near impossible for a billion dollar
company to fail, even if they try real hard.
> [ ... ]
>
> >> Oh -- the thrust bearing was loose. On the cross-slide of mine,
> >> the handcrank screws onto the leadscrew and then is locked by a cone
> >> nut which goes into a countersink in the crank (IIRC). It is easy to
> >> get this too tight. But it is also easy to tell that this is the source
> >> of the play by feel. You feel a bit of a "thud" as the bearing play is
> >> taken up, while the backlash in the actual leadscrew/net interface is
> >> less sudden. :-)
> >
> > The hand cranks are woodruff keyed to the screw shafts on the 5914, and
> > are kept on the screw shaft with a thread and cone nut as well.
>
> I had to go back to the manual to make sure that I had
> remembered it properly. It is a threaded collar of fairly small
> diameter with a step towards the crank on which the dial slips and
> rotates when the thumbscrew is loose. And yes, the collar *does* thread
> onto the end of the shaft, with a nut which locks against that, and then
> the crank screws on. But there is not the cone nut which I thought that
> I remembered.
On the 5914, the collar is not threaded (aside from the setscrew).
> >> > Before doing this, it helps to disassemble, clean, and lubricate the
> >> > entire dial assembly, so things can turn freely.
> >>
> >> Of course.
> >
> > Mine turned OK albeit with drag, and I worried that people might not
> > realize how much better it would work after a cleaning, in particular if
> > one wants to move the dial to a new zero without disturbing things.
>
> Indeed -- and the drag for the crank actually helps avoid
> disturbing the crank position while re-positioning the dial.
I found the drag to be a problem.
> [ ... ]
>
> >> The Nichols horizontal mill takes a lot less space than many,
> >> and (usually) offers a choice between leadscrew or lever feed through a
> >> rack-and-pinion drive for the X-axis feed. And -- there are a pair of
> >> micrometer stops which can be set up to restrict the X-axis travel
> >> rather precisely. Nice for certain forms of production work.
> >
> > I've seen pictures, but never met one in person. What do they weigh?
>
> About 1100 pounds.
That puts it into the same weight class as my Millrite MVI vertical mill
and of course the Clausing 5914. Seems to be a reasonable size for a
home shop. When I was looking for a lathe, some Logans came by, but I
let them pass because they weighed only ~300 pounds. Far too floppy for
my taste.
> It comes with a gearhead three-phase motor,
> so you would need a VFD or a rotary converter to run it. I can't see
> swapping in any other motor. Lots of cast iron in the base, the knee,
> and the table. The head is mounted to the side of the column via a
> dovetail, and there is a lever connected to a rack-and-quadrant gear
> arrangement to move the head up and down. There is a lever between the
> motor and the head pivoted in the middle of the column, so when the
> head goes up, the motor goes down, maintaining a constant spacing and
> thus constant belt tension. The really old ones have 1" shafts on both
> the motor and the quill, and the pulleys are double groove per speed,
> two speeds, and to get the other two speeds, you had to interchange the
> motor pulley with the spindle pulley.
>
> The later ones had a single belt instead of double, and five
> steps so you had a pretty good range of speeds. I've adapted the later
> pulleys to mine -- but I don't have the larger bore for a bigger drawbar
> which the newer ones had. I had to make my own mounting ring for the
> vertical head. But mine was a *very* old one. Both the horizontal head
> and the vertical adaptor use 40-taper NTMB holders and arbors.
Someday. Space is my issue. I saw a local Nichols horizontal hand mill
go for ~$500 about six months ago. There were few takers.
Joe Gwinn
|
|
Posted by DoN. Nichols on May 8, 2008, 12:41 am
Please log in for more thread options
[ ... ]
>> O.K. But you also probably don't have as much adjustment range
>> in the tapered gib so you can't tune out as much wear as you could in
>> the cross-slide.
>
> I don't understand. Both gibs are tapered.
With a shorter total dovetail, there is less linear travel
before the gib gets too far off center to give proper support. Assuming
that the taper is along the length rather than the width, which would
require an interesting adjustment system.
>> > Now this is a very severe test, yielding chips about -0.008" thick by
>> > 0.200" wide, and involves very large forces, so the toolbit rising is
>> > not a surprise. One has to push pretty hard before the tool starts to
>> > bite with an audible bump, and it then yields the 0.008" thick chip. If
>> > one maintains the pressure, one can make a very long and curly chip.
>>
>> Yes -- though the long and curly chip when parting can be a
>> problem, because it can wedge in the groove and result in a broken
>> parting tool.
>
>
> But the tool is upsidedown, so that won't happen. Well, not often.
One of the benefits of upside down is that chips tend to fall
out of the cut. But with a long curl, you would have the chip feeding
back cycle after cycle until there was enough to drag into the cutter
from pure edge friction.
[ ... ]
>> > But it has not happened yet. And while Solaris isn't completely
>> > hack-proof, it's orders of magnitude less vulnerable than Windows.
>>
>> And I've also turned off quite a few things which I don't need
>> or want. And, at least in unix systems, it is fairly easy to learn how
>> to turn things off or on.
>
> True enough.
And only a fool says that a system is hack-proof (using the
wrong sense of "hack".) I prefer to call that "cracking", as it has no
constructive target.
[ ... ]
>> > A college dorm has to be some kind of worst case test.
>>
>> Indeed so. Lots of machines in unskilled hands, tons of
>> bandwidth, so they can all be attacking each other. :-)
>
> And absolutely no common sense about which websites are likely to be a
> problem.
There is that, too. :-)
[ ... ]
>> > Now, Microsoft is slowly changing Windows so people don't have to run
>> > their software from an administrator account, but this is like turning
>> > the Queen Mary. But it five or ten years it will have been done.
>>
>> If they are still around by then. :-)
>
> Oh, they will for sure, It's damn near impossible for a billion dollar
> company to fail, even if they try real hard.
They appear to be trying "real hard". :-)
[ ... ]
>> > The hand cranks are woodruff keyed to the screw shafts on the 5914, and
>> > are kept on the screw shaft with a thread and cone nut as well.
>>
>> I had to go back to the manual to make sure that I had
>> remembered it properly. It is a threaded collar of fairly small
>> diameter with a step towards the crank on which the dial slips and
>> rotates when the thumbscrew is loose. And yes, the collar *does* thread
>> onto the end of the shaft, with a nut which locks against that, and then
>> the crank screws on. But there is not the cone nut which I thought that
>> I remembered.
>
> On the 5914, the collar is not threaded (aside from the setscrew).
O.K. A definite difference. You've seen the 5418 design in the
manual which you have.
[ ... ]
>> > Mine turned OK albeit with drag, and I worried that people might not
>> > realize how much better it would work after a cleaning, in particular if
>> > one wants to move the dial to a new zero without disturbing things.
>>
>> Indeed -- and the drag for the crank actually helps avoid
>> disturbing the crank position while re-positioning the dial.
>
> I found the drag to be a problem.
Well ... it needs to be just right. Too loose and vibration
will change it -- even with a balanced crank. Too tight, and it is easy
to overshoot when you get past the friction limit. Just right and you
can steady the crank with one hand as you loosen the thumbscrew, rotate
the outer dial, and re-tighten the thumbscrew.
[ ... ]
>> >> The Nichols horizontal mill takes a lot less space than many,
>> >> and (usually) offers a choice between leadscrew or lever feed through a
>> >> rack-and-pinion drive for the X-axis feed. And -- there are a pair of
>> >> micrometer stops which can be set up to restrict the X-axis travel
>> >> rather precisely. Nice for certain forms of production work.
>> >
>> > I've seen pictures, but never met one in person. What do they weigh?
>>
>> About 1100 pounds.
>
> That puts it into the same weight class as my Millrite MVI vertical mill
> and of course the Clausing 5914. Seems to be a reasonable size for a
> home shop. When I was looking for a lathe, some Logans came by, but I
> let them pass because they weighed only ~300 pounds. Far too floppy for
> my taste.
:-)
There are some larger Logans, I think. We've got an expert on
the newsgroup -- Scott Logan.
[ ... ]
> Someday. Space is my issue. I saw a local Nichols horizontal hand mill
> go for ~$500 about six months ago. There were few takers.
Mine was $200.00 on eBay -- and cost more to ship down to the DC
area from the Boston area. :-)
Enjoy,
DoN.
--
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
|
|
Posted by Joseph Gwinn on May 8, 2008, 9:20 am
Please log in for more thread options
>
> [ ... ]
>
> >> O.K. But you also probably don't have as much adjustment range
> >> in the tapered gib so you can't tune out as much wear as you could in
> >> the cross-slide.
> >
> > I don't understand. Both gibs are tapered.
>
> With a shorter total dovetail, there is less linear travel
> before the gib gets too far off center to give proper support. Assuming
> that the taper is along the length rather than the width, which would
> require an interesting adjustment system.
Well, in theory yes, but the gib adjustment range is the same for both
dovetails. The taper is indeed along the length, and is the same (5/32"
per foot) in both gibs.
> >> > Now this is a very severe test, yielding chips about -0.008" thick by
> >> > 0.200" wide, and involves very large forces, so the toolbit rising is
> >> > not a surprise. One has to push pretty hard before the tool starts to
> >> > bite with an audible bump, and it then yields the 0.008" thick chip. If
> >> > one maintains the pressure, one can make a very long and curly chip.
> >>
> >> Yes -- though the long and curly chip when parting can be a
> >> problem, because it can wedge in the groove and result in a broken
> >> parting tool.
> >
> >
> > But the tool is upsidedown, so that won't happen. Well, not often.
>
> One of the benefits of upside down is that chips tend to fall
> out of the cut. But with a long curl, you would have the chip feeding
> back cycle after cycle until there was enough to drag into the cutter
> from pure edge friction.
The tool tip is slightly angled, and so the chip usually curls into a
helix, versus a tight jellyroll.
> [ ... ]
>
> >> > But it has not happened yet. And while Solaris isn't completely
> >> > hack-proof, it's orders of magnitude less vulnerable than Windows.
> >>
> >> And I've also turned off quite a few things which I don't need
> >> or want. And, at least in unix systems, it is fairly easy to learn how
> >> to turn things off or on.
> >
> > True enough.
>
> And only a fool says that a system is hack-proof (using the
> wrong sense of "hack".) I prefer to call that "cracking", as it has no
> constructive target.
I don't think the hack/crack distinction has any traction in the
language at large. White hat versus black hat seems to be how the
distinction is made.
> [ ... ]
>
> >> > Now, Microsoft is slowly changing Windows so people don't have to run
> >> > their software from an administrator account, but this is like turning
> >> > the Queen Mary. But it five or ten years it will have been done.
> >>
> >> If they are still around by then. :-)
> >
> > Oh, they will for sure, It's damn near impossible for a billion dollar
> > company to fail, even if they try real hard.
>
> They appear to be trying "real hard". :-)
Well, they have always been good at understanding their business. After
all, they managed to achieve 90% market share selling products that were
far from "best in their class" technically.
> [ ... ]
>
> >> > The hand cranks are woodruff keyed to the screw shafts on the 5914, and
> >> > are kept on the screw shaft with a thread and cone nut as well.
> >>
> >> I had to go back to the manual to make sure that I had
> >> remembered it properly. It is a threaded collar of fairly small
> >> diameter with a step towards the crank on which the dial slips and
> >> rotates when the thumbscrew is loose. And yes, the collar *does* thread
> >> onto the end of the shaft, with a nut which locks against that, and then
> >> the crank screws on. But there is not the cone nut which I thought that
> >> I remembered.
> >
> > On the 5914, the collar is not threaded (aside from the setscrew).
>
> O.K. A definite difference. You've seen the 5418 design in the
> manual which you have.
Right. The mechanics are quite different.
> [ ... ]
>
> >> > Mine turned OK albeit with drag, and I worried that people might not
> >> > realize how much better it would work after a cleaning, in particular if
> >> > one wants to move the dial to a new zero without disturbing things.
> >>
> >> Indeed -- and the drag for the crank actually helps avoid
> >> disturbing the crank position while re-positioning the dial.
> >
> > I found the drag to be a problem.
>
> Well ... it needs to be just right. Too loose and vibration
> will change it -- even with a balanced crank. Too tight, and it is easy
> to overshoot when you get past the friction limit. Just right and you
> can steady the crank with one hand as you loosen the thumbscrew, rotate
> the outer dial, and re-tighten the thumbscrew.
Thumbscrew? Mine came with hex socket cap machine screws riding on
brass slugs. Hmm. The 5914 manual shows knurled thumbscrews, also
riding on brass slugs. So both thumbscrews were lost and replaced. The
cap screws are clumsy to use.
> [ ... ]
>
> >> >> The Nichols horizontal mill takes a lot less space than many,
> >> >> and (usually) offers a choice between leadscrew or lever feed through a
> >> >> rack-and-pinion drive for the X-axis feed. And -- there are a pair of
> >> >> micrometer stops which can be set up to restrict the X-axis travel
> >> >> rather precisely. Nice for certain forms of production work.
> >> >
> >> > I've seen pictures, but never met one in person. What do they weigh?
> >>
> >> About 1100 pounds.
> >
> > That puts it into the same weight class as my Millrite MVI vertical mill
> > and of course the Clausing 5914. Seems to be a reasonable size for a
> > home shop. When I was looking for a lathe, some Logans came by, but I
> > let them pass because they weighed only ~300 pounds. Far too floppy for
> > my taste.
>
> :-)
>
> There are some larger Logans, I think. We've got an expert on
> the newsgroup -- Scott Logan.
Yes, there are suitable 1000# Logan lathes, but none came onto the local
market while I was looking. Logans were a definite possibility because
Logan Actuator still exists and still supports their old iron.
> [ ... ]
>
> > Someday. Space is my issue. I saw a local Nichols horizontal hand mill
> > go for ~$500 about six months ago. There were few takers.
>
> Mine was $200.00 on eBay -- and cost more to ship down to the DC
> area from the Boston area. :-)
That's a bit of a drive. How much did the shipping cost, and what year
was this? Perhaps I should have considered non-local sources.
Joe Gwinn
|
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