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General Metalworking - All aspects of working with metal.
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Posted by DoN. Nichols on May 21, 2008, 1:19 am
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"References: " header folded into "X-references: " again.
>
[ ... ]
>> > Nuclear Magnetic Resonance Imaging (NMRI) was in fact perfectly
>> > accurate. But, the ignorant will always be with us - they didn't
>> > understand that "nuclear" didn't necessarily require or imply radiation.
>> > So, the name had to change.
>>
>> Yep -- and now you can freak some of the *operators* of the
>> devices by mentioning the full name. :-)
>
> I haven't tried that. Yet.
:-)
[ ... ]
>> > Certainly. But drywall screws are plentiful and cheap.
>>
>> Yes -- but I would expect a properly selected spring to do a
>> better job of cleaning the hole -- then perhaps followed by the
>> compressed air needle. (I'll have to make a snout for one of my air
>> guns to do that.)
>
> I found an air needle set that was threaded to fit into the snout of a
> real Schrader blowoff nozzle that I've had for years, long before I had
> a compressor to run it.
O.K. I haven't -- so if I want one, I'll have to make it or
order from MSC or somewhere similar.
[ ... ]
>> > If you keep this up, I'll have to become frightened.
>>
>> This was for if you want to do it a *lot*. And one of the
>> advantages of the CNC method is that it makes it easy to thread up to a
>> shoulder with no worries at whatever speed your lathe can manage. (The
>> Compact-5/CNC is limited to around 200 RPM because the Z-axis stepper is
>> too slow to handle coarse threads at higher spindle RPMs. (The Z axis
>> is parallel to the spindle -- along the bed for a lathe.
>
> Ahh. Now it becomes clear -- buy a CNC lathe. To go one better, it must
> weigh at least 3000#. Got to have sufficient rigidity.
Well ... My CNC lathe weighs something like 150-200 lbs. But it
is only 5" swing, and a lot of the weight is the transformers in the
sloped electronics housing which makes the backsplash panel as well as
the control panel.
The buttons especially are out of range of the splashes. :-)
[ ... ]
>> >> Do that and you reduce the rigidity of the mounting of the
>> >> toolpost and encourage chatter. :-)
>> >
>> > Not by much, as the plate is in compression, and can be accurately
>> > machined. And, all the rigidity problems I've had so far have been
>> > associated with loose slideways.
>>
>> The length of unsupported tool shank can be a problem even. I'm
>> against anything which reduces the rigidity of the toolpost assembly.
>
> I'm thinking a plate ~0.1" thick.
O.K. But still what matters is the reduction in surface contact
between the compound top and the toolpost bottom.
[ ... ]
>> > I'm leaning to the Dorian 7-71C, which appears to be made to allow use
>> > upsidedown. I will call Dorian and ask.
>>
>> O.K. Let me know how it works out.
>
> I called today, but have not yet talked to a human. Form their catalog,
> it appears that their 7-71C is intended to be used upsidedown, which
> would be perfect. It uses SGIH 19-2 blades, which are slightly larger
> than the 11/16" blades the Aloris BXA-7 uses, but one cal also get
> Dorian 7-71S holders, which accept SGIH 26-x blades, which are a good
> bit stouter.
>
> The Aloris BXA-71 uses a very stout blade, 1.5" high, but does not
> appear to be reversible - it has a one-sided bevel.
O.K.
[ ... ]
>> >> Ah yes -- the reason for a shallow 'V' groove in the top of the
>> >> parting tool to pinch the chip a bit narrower and reduce the chances of
>> >> this happening.
>> >
>> > Yes. I'll have to find a way to grind this feature into the blades.
>>
>> Get a Dremel and a stone perhaps 1" diameter. Use a diamond to
>> dress it to look like this:
>> __________
>> <____ ____>
>> ||
>> ||
>> ||
>> ||
>>
>> and run it along the top near the tip. Or -- if you have a small
>> surface grinder, get a thin wheel for that, and dress it as shown.
>
> This is doable, except for the surface grinder part.
Well ... the surface grinder was offered as an alternative to
the Dremel, not as mandatory. But it is probably the way that *I* would
do it.
[ ... ]
>> Hmm ... I have a shield which mounts on a rod on the back of the
>> headstock and it swivels out of the way for loading, or down to control
>> spray towards the operator. But it only works in the vicinity of the
>> chuck. For a carriage mounted one, you want something like the
>> T-slotted cross slide again. :-)
>
> Or drill and thread some mounting holes in the cast-iron cross-slide
> screw cover, which I've been considering.
Hmm ... bear in mind that the cross-slide screw cover gets
replaced when you put on the taper attachment -- at least for the plain
taper attachment, and I think also for the telescoping taper attachment.
And the existing cover is perhaps not rigid enough to resist
fracture if someone bumps the shield in the wrong way. perhaps mount it
to the screws which secure the cover -- they go into more meat in the
cross-slide.
>> > The Noga mist cooler does cause some drifting mist, which I find to
>> > cause a lot of coughing. I've taken to wearing a respirator to prevent
>> > breathing of the oil mist, but a better approach is required.
>>
>> From what I have read, the micro-drop is the best thing for
>> this.
>
> So I've heard, but they are quite expensive. What alternatives are
> there?
Other than making your own (which some here have done)? A
breathing mask with air pumped in form somewhere else, if you want to
keep using the mist.
> Maybe the solution is flood cooling plus a cover to catch what's flung
> off the workpiece. The cover need not be transparent, as even
> transparent covers will soon become opaque from the accumulated emulsion
> and crud.
That could do it. Transparent still helps to see where the
fresh coolant is currently hitting, so you can spot something going
wrong. :-)
And you really should have a separate cover for the chuck area,
because coolant or oil tends to walk along the workpiece and then get
slung out by the chuck jaws.
> With Rustlick WS-5050 emulsion, the baby blue milky fluid, decoration of
> nearby surfaces isn't a disaster, but will eventually stain the
> surfaces. A carriage-mounted shield should cut this down a lot.
Hmm ... perhaps get some rolls of the pre-painted aluminum used
for siding and staple it to the wall and the ceiling where the stripes
are trying to form. I did this where the surface grinder flings the
overshoot -- complete with a V-fold at the bottom to capture the dry
swarf so it can be swept into a container for disposal, instead of
falling to the floor.
>> > This is certainly only for roughing cuts. But speed is a good idea,
>> > even for HSMers.
>>
>> And patience after roughing to let it cool enough. I try to set
>> things up so I just finish the roughing before being called to dinner,
>> that way I have something to be doing while the workpiece cools. :-)
>
> I haven't been at the point where this would matter, at least not yet.
> But it will soon enough become something I need to worry about.
I have -- and have made the mistake of not waiting long enough
for it to cool off.
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 21, 2008, 9:11 am
Please log in for more thread options
> "References: " header folded into "X-references: " again.
>
> >
>
> [ ... ]
>
> >> > Certainly. But drywall screws are plentiful and cheap.
> >>
> >> Yes -- but I would expect a properly selected spring to do a
> >> better job of cleaning the hole -- then perhaps followed by the
> >> compressed air needle. (I'll have to make a snout for one of my air
> >> guns to do that.)
> >
> > I found an air needle set that was threaded to fit into the snout of a
> > real Schrader blowoff nozzle that I've had for years, long before I had
> > a compressor to run it.
>
> O.K. I haven't -- so if I want one, I'll have to make it or
> order from MSC or somewhere similar.
I got my set from MSC (# 02365526), for $17. I bought them sight
unseen, but the needles seem well enough made.
> [ ... ]
>
> >> > If you keep this up, I'll have to become frightened.
> >>
> >> This was for if you want to do it a *lot*. And one of the
> >> advantages of the CNC method is that it makes it easy to thread up to a
> >> shoulder with no worries at whatever speed your lathe can manage. (The
> >> Compact-5/CNC is limited to around 200 RPM because the Z-axis stepper is
> >> too slow to handle coarse threads at higher spindle RPMs. (The Z axis
> >> is parallel to the spindle -- along the bed for a lathe.
> >
> > Ahh. Now it becomes clear -- buy a CNC lathe. To go one better, it must
> > weigh at least 3000#. Got to have sufficient rigidity.
>
> Well ... My CNC lathe weighs something like 150-200 lbs. But it
> is only 5" swing, and a lot of the weight is the transformers in the
> sloped electronics housing which makes the backsplash panel as well as
> the control panel.
>
> The buttons especially are out of range of the splashes. :-)
Only 200 pounds? What a let-down. The good news is that one can have a
full-coverage splash shield, just like on those machining centers.
> [ ... ]
>
> >> >> Do that and you reduce the rigidity of the mounting of the
> >> >> toolpost and encourage chatter. :-)
> >> >
> >> > Not by much, as the plate is in compression, and can be accurately
> >> > machined. And, all the rigidity problems I've had so far have been
> >> > associated with loose slideways.
> >>
> >> The length of unsupported tool shank can be a problem even. I'm
> >> against anything which reduces the rigidity of the toolpost assembly.
> >
> > I'm thinking a plate ~0.1" thick.
>
> O.K. But still what matters is the reduction in surface contact
> between the compound top and the toolpost bottom.
I'm having a problem believing that such a spacer, if well made and not
too thick, will materially affect the rigidity, compared to the
slideways.
> [ ... ]
>
> >> > I'm leaning to the Dorian 7-71C, which appears to be made to allow use
> >> > upsidedown. I will call Dorian and ask.
> >>
> >> O.K. Let me know how it works out.
> >
> > I called today, but have not yet talked to a human. Form their catalog,
> > it appears that their 7-71C is intended to be used upsidedown, which
> > would be perfect. It uses SGIH 19-2 blades, which are slightly larger
> > than the 11/16" blades the Aloris BXA-7 uses, but one can also get
> > Dorian 7-71S holders, which accept SGIH 26-x blades, which are a good
> > bit stouter.
> >
> > The Aloris BXA-71 uses a very stout blade, 1.5" high, but does not
> > appear to be reversible - it has a one-sided bevel.
>
> O.K.
No news yet.
> [ ... ]
>
> >> Hmm ... I have a shield which mounts on a rod on the back of the
> >> headstock and it swivels out of the way for loading, or down to control
> >> spray towards the operator. But it only works in the vicinity of the
> >> chuck. For a carriage mounted one, you want something like the
> >> T-slotted cross slide again. :-)
> >
> > Or drill and thread some mounting holes in the cast-iron cross-slide
> > screw cover, which I've been considering.
>
> Hmm ... bear in mind that the cross-slide screw cover gets
> replaced when you put on the taper attachment -- at least for the plain
> taper attachment, and I think also for the telescoping taper attachment.
>
> And the existing cover is perhaps not rigid enough to resist
> fracture if someone bumps the shield in the wrong way. Perhaps mount it
> to the screws which secure the cover -- they go into more meat in the
> cross-slide.
I was thinking something not so rigid, like a piece of copper or
aluminum flashing, to be hand bent into shape as needed. But using the
same screws as hold the cover is a good idea too. It's easy to dimple
the copper to work with the big flat-head screws, but a ~5" long steel
bar clamping the flashing to the cross slide may be a better way.
> >> > The Noga mist cooler does cause some drifting mist, which I find to
> >> > cause a lot of coughing. I've taken to wearing a respirator to prevent
> >> > breathing of the oil mist, but a better approach is required.
> >>
> >> From what I have read, the micro-drop is the best thing for
> >> this.
> >
> > So I've heard, but they are quite expensive. What alternatives are
> > there?
>
> Other than making your own (which some here have done)?
Hmm. Has anyone published pictures or plans?
> A breathing mask with air pumped in form somewhere else, if you want to
> keep using the mist.
The 3M respirator is cheap enough, and work well, even if it makes me
look like a preying mantis.
>
> > Maybe the solution is flood cooling plus a cover to catch what's flung
> > off the workpiece. The cover need not be transparent, as even
> > transparent covers will soon become opaque from the accumulated emulsion
> > and crud.
>
> That could do it. Transparent still helps to see where the
> fresh coolant is currently hitting, so you can spot something going
> wrong. :-)
Polycarbonate. And easily replaced, because the coolant will soon
damage the plastic.
> And you really should have a separate cover for the chuck area,
> because coolant or oil tends to walk along the workpiece and then get
> slung out by the chuck jaws.
Hmm. Good point.
> > With Rustlick WS-5050 emulsion, the baby blue milky fluid, decoration of
> > nearby surfaces isn't a disaster, but will eventually stain the
> > surfaces. A carriage-mounted shield should cut this down a lot.
>
> Hmm ... perhaps get some rolls of the pre-painted aluminum used
> for siding and staple it to the wall and the ceiling where the stripes
> are trying to form. I did this where the surface grinder flings the
> overshoot -- complete with a V-fold at the bottom to capture the dry
> swarf so it can be swept into a container for disposal, instead of
> falling to the floor.
I had been thinking of hanging some cheap fabric (like the muslin used
for painter's dropcloths) to intercept the stripes.
> >> > This is certainly only for roughing cuts. But speed is a good idea,
> >> > even for HSMers.
> >>
> >> And patience after roughing to let it cool enough. I try to set
> >> things up so I just finish the roughing before being called to dinner,
> >> that way I have something to be doing while the workpiece cools. :-)
> >
> > I haven't been at the point where this would matter, at least not yet.
> > But it will soon enough become something I need to worry about.
>
> I have -- and have made the mistake of not waiting long enough
> for it to cool off.
I imagine I will too. One advantage of flooding with water emulsions is
that things don't heat up that much.
Joe Gwinn
|
|
Posted by DoN. Nichols on May 21, 2008, 8:06 pm
Please log in for more thread options >
>> "References: " header folded into "X-references: " again.
[ ... ]
>> > I found an air needle set that was threaded to fit into the snout of a
>> > real Schrader blowoff nozzle that I've had for years, long before I had
>> > a compressor to run it.
>>
>> O.K. I haven't -- so if I want one, I'll have to make it or
>> order from MSC or somewhere similar.
>
> I got my set from MSC (# 02365526), for $17. I bought them sight
> unseen, but the needles seem well enough made.
O.K. I'll keep that in mind for my next order from MSC.
[ ... ]
>> > Ahh. Now it becomes clear -- buy a CNC lathe. To go one better, it must
>> > weigh at least 3000#. Got to have sufficient rigidity.
>>
>> Well ... My CNC lathe weighs something like 150-200 lbs. But it
>> is only 5" swing, and a lot of the weight is the transformers in the
>> sloped electronics housing which makes the backsplash panel as well as
>> the control panel.
>>
>> The buttons especially are out of range of the splashes. :-)
>
> Only 200 pounds? What a let-down. The good news is that one can have a
> full-coverage splash shield, just like on those machining centers.
This one has a box of electronics behind the lathe which
controls splash to the back. There is a splash shield which is hinged
to the front edge of the carriage just past the outermost travel of the
cross-slide. The shield is a smokey plastic -- Lexan like I think --
which has a shape like this (view with a fixed pitch font to avoid
distortion of the shape:
______________
/
/
/
/
/
O <--- hinge
I actually have two of them -- one full width all over, and the
other with a cutout near the tailstock-end of the cover to clear the
long motor which runs the (optional) tool turret.
No coolant in this lathe, but the whole thing, including
headstock and (DC) motor are in the chip pan, which extends back to
where the electronics box starts.
I did a quick search of eBay, but while there is a manual
Comapct-5 being offered, there is no CNC version, which is much heavier
overall, even though it uses the same bed, and mostly the same
headstock.
>> [ ... ]
>>
>> >> >> Do that and you reduce the rigidity of the mounting of the
>> >> >> toolpost and encourage chatter. :-)
>> >> >
>> >> > Not by much, as the plate is in compression, and can be accurately
>> >> > machined. And, all the rigidity problems I've had so far have been
>> >> > associated with loose slideways.
>> >>
>> >> The length of unsupported tool shank can be a problem even. I'm
>> >> against anything which reduces the rigidity of the toolpost assembly.
>> >
>> > I'm thinking a plate ~0.1" thick.
>>
>> O.K. But still what matters is the reduction in surface contact
>> between the compound top and the toolpost bottom.
>
> I'm having a problem believing that such a spacer, if well made and not
> too thick, will materially affect the rigidity, compared to the
> slideways.
O.K. I have my opinion, and you have yours. I just feel that
*any* contribution to a loss of rigidity is to be avoided.
[ ... ]
>> > The Aloris BXA-71 uses a very stout blade, 1.5" high, but does not
>> > appear to be reversible - it has a one-sided bevel.
>>
>> O.K.
>
> No news yet.
O.K.
>
>> [ ... ]
>>
>> >> Hmm ... I have a shield which mounts on a rod on the back of the
>> >> headstock and it swivels out of the way for loading, or down to control
>> >> spray towards the operator. But it only works in the vicinity of the
>> >> chuck. For a carriage mounted one, you want something like the
>> >> T-slotted cross slide again. :-)
>> >
>> > Or drill and thread some mounting holes in the cast-iron cross-slide
>> > screw cover, which I've been considering.
>>
>> Hmm ... bear in mind that the cross-slide screw cover gets
>> replaced when you put on the taper attachment -- at least for the plain
>> taper attachment, and I think also for the telescoping taper attachment.
>>
>> And the existing cover is perhaps not rigid enough to resist
>> fracture if someone bumps the shield in the wrong way. Perhaps mount it
>> to the screws which secure the cover -- they go into more meat in the
>> cross-slide.
>
> I was thinking something not so rigid, like a piece of copper or
> aluminum flashing, to be hand bent into shape as needed. But using the
> same screws as hold the cover is a good idea too. It's easy to dimple
> the copper to work with the big flat-head screws, but a ~5" long steel
> bar clamping the flashing to the cross slide may be a better way.
It helps to have the shield clear, so you get more illumination
through to the spindle, even if you can't see clearly. Go for something
like Lexan, not something as brittle as Plexiglass.
>> >> > The Noga mist cooler does cause some drifting mist, which I find to
>> >> > cause a lot of coughing. I've taken to wearing a respirator to prevent
>> >> > breathing of the oil mist, but a better approach is required.
>> >>
>> >> From what I have read, the micro-drop is the best thing for
>> >> this.
>> >
>> > So I've heard, but they are quite expensive. What alternatives are
>> > there?
>>
>> Other than making your own (which some here have done)?
>
> Hmm. Has anyone published pictures or plans?
I think that there are some photos which were posted, but I did
not bother to save a link. If you care enough, do a Google search for
the newsgroup over the past five years I think should do it.
>
>> A breathing mask with air pumped in form somewhere else, if you want to
>> keep using the mist.
>
> The 3M respirator is cheap enough, and work well, even if it makes me
> look like a preying mantis.
Is that supplied air, or just depending on filters? I would
suggest that supplied air would be less likely to clog during a long
machining session.
>>
>> > Maybe the solution is flood cooling plus a cover to catch what's flung
>> > off the workpiece. The cover need not be transparent, as even
>> > transparent covers will soon become opaque from the accumulated emulsion
>> > and crud.
>>
>> That could do it. Transparent still helps to see where the
>> fresh coolant is currently hitting, so you can spot something going
>> wrong. :-)
>
> Polycarbonate. And easily replaced, because the coolant will soon
> damage the plastic.
Hmm ... no experience with that so far.
>
>> And you really should have a separate cover for the chuck area,
>> because coolant or oil tends to walk along the workpiece and then get
>> slung out by the chuck jaws.
>
> Hmm. Good point.
Check that the splash lines line up with the chuck body, instead
of being spread through where you actually do your cutting. :-)
>
>> > With Rustlick WS-5050 emulsion, the baby blue milky fluid, decoration of
>> > nearby surfaces isn't a disaster, but will eventually stain the
>> > surfaces. A carriage-mounted shield should cut this down a lot.
>>
>> Hmm ... perhaps get some rolls of the pre-painted aluminum used
>> for siding and staple it to the wall and the ceiling where the stripes
>> are trying to form. I did this where the surface grinder flings the
>> overshoot -- complete with a V-fold at the bottom to capture the dry
>> swarf so it can be swept into a container for disposal, instead of
>> falling to the floor.
>
> I had been thinking of hanging some cheap fabric (like the muslin used
> for painter's dropcloths) to intercept the stripes.
O.K.
[ ... ]
>> >> And patience after roughing to let it cool enough. I try to set
>> >> things up so I just finish the roughing before being called to dinner,
>> >> that way I have something to be doing while the workpiece cools. :-)
>> >
>> > I haven't been at the point where this would matter, at least not yet.
>> > But it will soon enough become something I need to worry about.
>>
>> I have -- and have made the mistake of not waiting long enough
>> for it to cool off.
>
> I imagine I will too. One advantage of flooding with water emulsions is
> that things don't heat up that much.
Agreed -- but you still should beware of heat effects if you are
after a precise fit. As long as you are working steel, if you've got
some magic way to get the measuring tools to the same temperature as
the workpiece, you won't have to wait -- but I think that waiting is
easier. :-)
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 22, 2008, 9:00 am
Please log in for more thread options
> >
> >> "References: " header folded into "X-references: " again.
>
> [ ... ]
>
> >> > Ahh. Now it becomes clear -- buy a CNC lathe. To go one better, it must
> >> > weigh at least 3000#. Got to have sufficient rigidity.
> >>
> >> Well ... My CNC lathe weighs something like 150-200 lbs. But it
> >> is only 5" swing, and a lot of the weight is the transformers in the
> >> sloped electronics housing which makes the backsplash panel as well as
> >> the control panel.
> >>
> >> The buttons especially are out of range of the splashes. :-)
> >
> > Only 200 pounds? What a let-down. The good news is that one can have a
> > full-coverage splash shield, just like on those machining centers.
>
> This one has a box of electronics behind the lathe which
> controls splash to the back. There is a splash shield which is hinged
> to the front edge of the carriage just past the outermost travel of the
> cross-slide. The shield is a smokey plastic -- Lexan like I think --
> which has a shape like this (view with a fixed pitch font to avoid
> distortion of the shape:
>
> ______________
> /
> /
> /
> /
> /
> O <--- hinge
>
> I actually have two of them -- one full width all over, and the
> other with a cutout near the tailstock-end of the cover to clear the
> long motor which runs the (optional) tool turret.
>
> No coolant in this lathe, but the whole thing, including
> headstock and (DC) motor are in the chip pan, which extends back to
> where the electronics box starts.
>
> I did a quick search of eBay, but while there is a manual
> Comapct-5 being offered, there is no CNC version, which is much heavier
> overall, even though it uses the same bed, and mostly the same
> headstock.
I've seen photos of this kind of hinged cover.
I'll be learning the 5914 for at least a year.
> >> [ ... ]
> >>
> >> >> >> Do that and you reduce the rigidity of the mounting of the
> >> >> >> toolpost and encourage chatter. :-)
> >> >> >
> >> >> > Not by much, as the plate is in compression, and can be accurately
> >> >> > machined. And, all the rigidity problems I've had so far have been
> >> >> > associated with loose slideways.
> >> >>
> >> >> The length of unsupported tool shank can be a problem even. I'm
> >> >> against anything which reduces the rigidity of the toolpost assembly.
> >> >
> >> > I'm thinking a plate ~0.1" thick.
> >>
> >> O.K. But still what matters is the reduction in surface contact
> >> between the compound top and the toolpost bottom.
> >
> > I'm having a problem believing that such a spacer, if well made and not
> > too thick, will materially affect the rigidity, compared to the
> > slideways.
>
> O.K. I have my opinion, and you have yours. I just feel that
> *any* contribution to a loss of rigidity is to be avoided.
The key is the "materially". I think that the three slideways in series
are at best a tenth as rigid as even a 0.25" thick machined steel spacer.
> [ ... ]
>
> >> > The Aloris BXA-71 uses a very stout blade, 1.5" high, but does not
> >> > appear to be reversible - it has a one-sided bevel.
> >>
> >> O.K.
> >
> > No news [from Dorian] yet.
>
> O.K.
I talked to Dorian Tool yesterday. They confirmed that both the 7-71C
and the 71S cutoff blade holders can be mounted upsidedown, being
drilled and tapped on both top and bottom to accept the height
adjustment hardware. In fact, these holders can be mounted just about
any way, between their symmetry and threaded holes top and bottom.
I will get a 7-71C holder, SGIH 19-2 blade, and GTN-2 inserts.
The 71S holder can accept far larger blades, but I decided that the
7-71C will solve the problem to the limits of the 5914 lathe.
> >> [ ... ]
> >>
> >> >> Hmm ... I have a shield which mounts on a rod on the back of the
> >> >> headstock and it swivels out of the way for loading, or down to control
> >> >> spray towards the operator. But it only works in the vicinity of the
> >> >> chuck. For a carriage mounted one, you want something like the
> >> >> T-slotted cross slide again. :-)
> >> >
> >> > Or drill and thread some mounting holes in the cast-iron cross-slide
> >> > screw cover, which I've been considering.
> >>
> >> Hmm ... bear in mind that the cross-slide screw cover gets
> >> replaced when you put on the taper attachment -- at least for the plain
> >> taper attachment, and I think also for the telescoping taper attachment.
> >>
> >> And the existing cover is perhaps not rigid enough to resist
> >> fracture if someone bumps the shield in the wrong way. Perhaps mount it
> >> to the screws which secure the cover -- they go into more meat in the
> >> cross-slide.
> >
> > I was thinking something not so rigid, like a piece of copper or
> > aluminum flashing, to be hand bent into shape as needed. But using the
> > same screws as hold the cover is a good idea too. It's easy to dimple
> > the copper to work with the big flat-head screws, but a ~5" long steel
> > bar clamping the flashing to the cross slide may be a better way.
>
> It helps to have the shield clear, so you get more illumination
> through to the spindle, even if you can't see clearly. Go for something
> like Lexan, not something as brittle as Plexiglass.
Ah. Thin lexan (polycarbonate) sheet it is, not metal.
> >> >> > The Noga mist cooler does cause some drifting mist, which I find to
> >> >> > cause a lot of coughing. I've taken to wearing a respirator to
> >> >> > prevent
> >> >> > breathing of the oil mist, but a better approach is required.
> >> >>
> >> >> From what I have read, the micro-drop is the best thing for
> >> >> this.
> >> >
> >> > So I've heard, but they are quite expensive. What alternatives are
> >> > there?
> >>
> >> Other than making your own (which some here have done)?
> >
> > Hmm. Has anyone published pictures or plans?
>
> I think that there are some photos which were posted, but I did
> not bother to save a link. If you care enough, do a Google search for
> the newsgroup over the past five years I think should do it.
OK. I may dimly recall the discussion.
> >> A breathing mask with air pumped in form somewhere else, if you want to
> >> keep using the mist.
> >
> > The 3M respirator is cheap enough, and work well, even if it makes me
> > look like a preying mantis.
>
> Is that supplied air, or just depending on filters? I would
> suggest that supplied air would be less likely to clog during a long
> machining session.
The mask uses filters. I don't think they will clog all that fast, as I
am religious about running the mister only while actually needed. But
we shall see. The filters are commonplace and cheap.
The problem with supplied air is entanglement with the air hose.
> >> > Maybe the solution is flood cooling plus a cover to catch what's flung
> >> > off the workpiece. The cover need not be transparent, as even
> >> > transparent covers will soon become opaque from the accumulated emulsion
> >> > and crud.
> >>
> >> That could do it. Transparent still helps to see where the
> >> fresh coolant is currently hitting, so you can spot something going
> >> wrong. :-)
> >
> > Polycarbonate. And easily replaced, because the coolant will soon
> > damage the plastic.
>
> Hmm ... no experience with that so far.
Lexan is the brand name for one manufacturer's polycarbonate resin.
My worry about damage comes from observing that polycarbonate windows
soon become frosted-looking. This may be more due to UV in sunlight
than chemical exposure, but polycarbonate is famous for low chemical
resistance, and oils are hard on many transparent plastics.
> >> And you really should have a separate cover for the chuck area,
> >> because coolant or oil tends to walk along the workpiece and then get
> >> slung out by the chuck jaws.
> >
> > Hmm. Good point.
>
> Check that the splash lines line up with the chuck body, instead
> of being spread through where you actually do your cutting. :-)
Currently, the splash line lines up with the chuck face, but I have not
done much cutting anywhere else.
My first attempt to turn a 1.5" diameter by 24" long 6061 bar between
centers chattered badly, and I have not yet had time to figure out why.
A piece of this same stock held in the 3-jaw chuck machined smoothly.
> [ ... ]
>
> >> >> And patience after roughing to let it cool enough. I try to set
> >> >> things up so I just finish the roughing before being called to dinner,
> >> >> that way I have something to be doing while the workpiece cools. :-)
> >> >
> >> > I haven't been at the point where this would matter, at least not yet.
> >> > But it will soon enough become something I need to worry about.
> >>
> >> I have -- and have made the mistake of not waiting long enough
> >> for it to cool off.
> >
> > I imagine I will too. One advantage of flooding with water emulsions is
> > that things don't heat up that much.
>
> Agreed -- but you still should beware of heat effects if you are
> after a precise fit. As long as you are working steel, if you've got
> some magic way to get the measuring tools to the same temperature as
> the workpiece, you won't have to wait -- but I think that waiting is
> easier. :-)
I recall that the standards lab folk ran all their calibration resistors
and resistance standards in stirred oil baths, precisely to control
temperature effects. So, if we ran the lathe in an oil bath, we could
both ensure temperature uniformity and provide true flood cooling to the
cutter. And, with proper design, completely eliminate splatter lines.
Joe Gwinn
|
|
Posted by DoN. Nichols on May 22, 2008, 10:25 pm
Please log in for more thread options >
[ ... ]
>> > Only 200 pounds? What a let-down. The good news is that one can have a
>> > full-coverage splash shield, just like on those machining centers.
>>
>> This one has a box of electronics behind the lathe which
>> controls splash to the back. There is a splash shield which is hinged
>> to the front edge of the carriage just past the outermost travel of the
>> cross-slide. The shield is a smokey plastic -- Lexan like I think --
>> which has a shape like this (view with a fixed pitch font to avoid
>> distortion of the shape:
>>
>> ______________
>> /
>> /
>> /
>> /
>> /
>> O <--- hinge
>>
>> I actually have two of them -- one full width all over, and the
>> other with a cutout near the tailstock-end of the cover to clear the
>> long motor which runs the (optional) tool turret.
>>
>> No coolant in this lathe, but the whole thing, including
>> headstock and (DC) motor are in the chip pan, which extends back to
>> where the electronics box starts.
>>
>> I did a quick search of eBay, but while there is a manual
>> Compact-5 being offered, there is no CNC version, which is much heavier
>> overall, even though it uses the same bed, and mostly the same
>> headstock.
>
> I've seen photos of this kind of hinged cover.
O.K.
> I'll be learning the 5914 for at least a year.
Understood. I've been using my 5418 for perhaps a decade now.
No room for anything larger. :-)
[ ... ]
>> >> > The Aloris BXA-71 uses a very stout blade, 1.5" high, but does not
>> >> > appear to be reversible - it has a one-sided bevel.
>> >>
>> >> O.K.
>> >
>> > No news [from Dorian] yet.
>>
>> O.K.
>
> I talked to Dorian Tool yesterday. They confirmed that both the 7-71C
> and the 71S cutoff blade holders can be mounted upsidedown, being
> drilled and tapped on both top and bottom to accept the height
> adjustment hardware. In fact, these holders can be mounted just about
> any way, between their symmetry and threaded holes top and bottom.
Sounds good!
> I will get a 7-71C holder, SGIH 19-2 blade, and GTN-2 inserts.
>
> The 71S holder can accept far larger blades, but I decided that the
> 7-71C will solve the problem to the limits of the 5914 lathe.
Understood.
[ ... ]
>> >> And the existing cover is perhaps not rigid enough to resist
>> >> fracture if someone bumps the shield in the wrong way. Perhaps mount it
>> >> to the screws which secure the cover -- they go into more meat in the
>> >> cross-slide.
>> >
>> > I was thinking something not so rigid, like a piece of copper or
>> > aluminum flashing, to be hand bent into shape as needed. But using the
>> > same screws as hold the cover is a good idea too. It's easy to dimple
>> > the copper to work with the big flat-head screws, but a ~5" long steel
>> > bar clamping the flashing to the cross slide may be a better way.
>>
>> It helps to have the shield clear, so you get more illumination
>> through to the spindle, even if you can't see clearly. Go for something
>> like Lexan, not something as brittle as Plexiglass.
>
> Ah. Thin lexan (polycarbonate) sheet it is, not metal.
O.K.
[ ... micro-drop cutting lube ... ]
>> >> Other than making your own (which some here have done)?
>> >
>> > Hmm. Has anyone published pictures or plans?
>>
>> I think that there are some photos which were posted, but I did
>> not bother to save a link. If you care enough, do a Google search for
>> the newsgroup over the past five years I think should do it.
>
> OK. I may dimly recall the discussion.
O.K. Next trick if finding it. :-)
>> >> A breathing mask with air pumped in form somewhere else, if you want to
>> >> keep using the mist.
>> >
>> > The 3M respirator is cheap enough, and work well, even if it makes me
>> > look like a preying mantis.
>>
>> Is that supplied air, or just depending on filters? I would
>> suggest that supplied air would be less likely to clog during a long
>> machining session.
>
> The mask uses filters. I don't think they will clog all that fast, as I
> am religious about running the mister only while actually needed. But
> we shall see. The filters are commonplace and cheap.
>
> The problem with supplied air is entanglement with the air hose.
Overhead drop?
>
>> >> > Maybe the solution is flood cooling plus a cover to catch what's flung
>> >> > off the workpiece. The cover need not be transparent, as even
>> >> > transparent covers will soon become opaque from the accumulated emulsion
>> >> > and crud.
>> >>
>> >> That could do it. Transparent still helps to see where the
>> >> fresh coolant is currently hitting, so you can spot something going
>> >> wrong. :-)
>> >
>> > Polycarbonate. And easily replaced, because the coolant will soon
>> > damage the plastic.
>>
>> Hmm ... no experience with that so far.
>
> Lexan is the brand name for one manufacturer's polycarbonate resin.
>
> My worry about damage comes from observing that polycarbonate windows
> soon become frosted-looking. This may be more due to UV in sunlight
> than chemical exposure, but polycarbonate is famous for low chemical
> resistance, and oils are hard on many transparent plastics.
IIRC, it is Plexiglass (acrylic) which tends to grow cracks
along every stress line after contact with oil.
>> >> And you really should have a separate cover for the chuck area,
>> >> because coolant or oil tends to walk along the workpiece and then get
>> >> slung out by the chuck jaws.
>> >
>> > Hmm. Good point.
>>
>> Check that the splash lines line up with the chuck body, instead
>> of being spread through where you actually do your cutting. :-)
>
> Currently, the splash line lines up with the chuck face, but I have not
> done much cutting anywhere else.
O.K.
> My first attempt to turn a 1.5" diameter by 24" long 6061 bar between
> centers chattered badly, and I have not yet had time to figure out why.
> A piece of this same stock held in the 3-jaw chuck machined smoothly.
Freedom for the workpiece and dog tail to rotate a bit within
the gap in the drive plate? I believe that it was common to take wet
rawhide strips to tie it in contact with the driving face, and wait for
that to dry before cutting.
[ ... ]
>> > I imagine I will too. One advantage of flooding with water emulsions is
>> > that things don't heat up that much.
>>
>> Agreed -- but you still should beware of heat effects if you are
>> after a precise fit. As long as you are working steel, if you've got
>> some magic way to get the measuring tools to the same temperature as
>> the workpiece, you won't have to wait -- but I think that waiting is
>> easier. :-)
>
> I recall that the standards lab folk ran all their calibration resistors
> and resistance standards in stirred oil baths, precisely to control
> temperature effects.
Of course, depending on the number of significant figures
needed, you needed to control to within a small fraction of a degree.
> So, if we ran the lathe in an oil bath, we could
> both ensure temperature uniformity and provide true flood cooling to the
> cutter. And, with proper design, completely eliminate splatter lines.
But you are back to needing supplied air to run it. :-)
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 ---
|
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