I've had no luck trying to locate information, adapters or lenses for
miniature cameras with NF mount lenses.

The NF designation isn't related to the thread style, but instead is a
miniature version of of C or CS mounts, which instead of being 25mm, the NF
is 16mm diameter (or maybe a 16.5mm).

I wasn't able to locate the specifications of the NF mount threads. I'm not
sure what thread pitches are commonly used on camera/optical equipment
(although 32 tpi is a rough guesstimate).

The miniature video cameras I'm interested in are the SONY XC versions,
which use the NF mount and utilize a 1/3" CCD imaging device.

Adapters exist to adapt the larger C mount series lenses to NF, but my
preference is to use miniature lenses with the mini cameras.

I expect to use aluminum for fabrication (or possibly brass) and I suppose
that anodizing is probably about the only option for coatings for aluminum
fittings.

Much of the threading for optical parts is very near a shoulder and a narrow
cutting tool would need to be used, maybe a ground HSS cutoff tool for
external threads.

I would most likely approach the threading operation with a hand crank since
the threads on optical fittings are generally only a few revolutions.

Please share any info related to threading practices, specifications or
fabrication of small threaded components that could be applied to optical
equipment.

Any guidance would be appreciated.

Another area of interest is adapting various optical components' focal
length. I've found online info about the various camera lens optical
elements (vague, Wikipedia), but would like to have any recommendations for
references to optical mechanics.
I have a Selsi/Edmond diopter gauge, but the minimum lens size it can
measure is about 20mm diameter.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html

"Wild_Bill" wrote in message
...
I've had no luck trying to locate information, adapters or lenses for
miniature cameras with NF mount lenses.

The NF designation isn't related to the thread style, but instead is a
miniature version of of C or CS mounts, which instead of being 25mm, the
NF is 16mm diameter (or maybe a 16.5mm).

I wasn't able to locate the specifications of the NF mount threads. I'm
not sure what thread pitches are commonly used on camera/optical equipment
(although 32 tpi is a rough guesstimate).

The miniature video cameras I'm interested in are the SONY XC versions,
which use the NF mount and utilize a 1/3" CCD imaging device.

Adapters exist to adapt the larger C mount series lenses to NF, but my
preference is to use miniature lenses with the mini cameras.

I expect to use aluminum for fabrication (or possibly brass) and I suppose
that anodizing is probably about the only option for coatings for aluminum
fittings.

Much of the threading for optical parts is very near a shoulder and a
narrow cutting tool would need to be used, maybe a ground HSS cutoff tool
for external threads.

I would most likely approach the threading operation with a hand crank
since the threads on optical fittings are generally only a few
revolutions.

Please share any info related to threading practices, specifications or
fabrication of small threaded components that could be applied to optical
equipment.

Any guidance would be appreciated.

Another area of interest is adapting various optical components' focal
length. I've found online info about the various camera lens optical
elements (vague, Wikipedia), but would like to have any recommendations
for references to optical mechanics.
I have a Selsi/Edmond diopter gauge, but the minimum lens size it can
measure is about 20mm diameter.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


maybe a dig here would yeild something:

http://www.truetex.com/micad.htm

maybe a dig here would yeild something:

http://www.truetex.com/micad.htm


Ha - just found the site owner is a regular here!

"Wild_Bill" wrote in message
...
I've had no luck trying to locate information, adapters or lenses for
miniature cameras with NF mount lenses.

The NF designation isn't related to the thread style, but instead is a
miniature version of of C or CS mounts, which instead of being 25mm, the
NF is 16mm diameter (or maybe a 16.5mm).

I wasn't able to locate the specifications of the NF mount threads. I'm
not sure what thread pitches are commonly used on camera/optical equipment
(although 32 tpi is a rough guesstimate).

The miniature video cameras I'm interested in are the SONY XC versions,
which use the NF mount and utilize a 1/3" CCD imaging device.

You need a lens not normally available for a mini board camera???

I suspect that the threads may be metric since most of them are made in the
eastern part of the world.

On Nov 19, 11:07*pm, "Wild_Bill" wrote:
I've had no luck trying to locate information, adapters or lenses for
miniature cameras with NF mount lenses.

The NF designation isn't related to the thread style, but instead is a
miniature version of of C or CS mounts, which instead of being 25mm, the NF
is 16mm diameter (or maybe a 16.5mm).

I wasn't able to locate the specifications of the NF mount threads. I'm not
sure what thread pitches are commonly used on camera/optical equipment
(although 32 tpi is a rough guesstimate).

The miniature video cameras I'm interested in are the SONY XC versions,
which use the NF mount and utilize a 1/3" CCD imaging device.

Adapters exist to adapt the larger C mount series lenses to NF, but my
preference is to use miniature lenses with the mini cameras.

I expect to use aluminum for fabrication (or possibly brass) and I suppose
that anodizing is probably about the only option for coatings for aluminum
fittings.

Much of the threading for optical parts is very near a shoulder and a narrow
cutting tool would need to be used, maybe a ground HSS cutoff tool for
external threads.

I would most likely approach the threading operation with a hand crank since
the threads on optical fittings are generally only a few revolutions.

Please share any info related to threading practices, specifications or
fabrication of small threaded components that could be applied to optical
equipment.

Any guidance would be appreciated.

Another area of interest is adapting various optical components' focal
length. I've found online info about the various camera lens optical
elements (vague, Wikipedia), but would like to have any recommendations for
references to optical mechanics.
I have a Selsi/Edmond diopter gauge, but the minimum lens size it can
measure is about 20mm diameter.

--
WB
.........
metalworking projectswww.kwagmire.com/metal_proj.html

Spec for the sony LO-999CMT C-NF adapter shows the thread type.

http://www.ccddirect.com/store/custo...cat=263&page=6
http://ccddirect--documents.com/pdf/lo999cmt.pdf

M17x0.75 external thread

Dave

Thanks, I've seen Richard's pages, although they seem to be expanded since I
last looked, and this is the first reference I've seen for the NF mount
thread size, 17mm x 0.75.

Richard's truetex camera/microscope adapters page also has some very good
reference links at the end.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"K Ludger" wrote in message
...


maybe a dig here would yeild something:

http://www.truetex.com/micad.htm

Thanks Bob, the specs I've seen for mini board camera lenses are 12mm x 0.5
and the NF mount threads are likely to be 17mm x 0.75.

The mini board camera lenses might be one option if the focal length would
be compatible.
The board cams I have, have been lent to a friend, or I would have tried the
lenses (although some lenses are superglued in place).
Those lenses sit fairly close to the image device, so they might not have
the optical spacing needed for the SONY XC cam (focal plane, I guess).
I won't know about the board cam lenses until I try a couple of 'em to see
what they'll do.
The majority of them are fixed-focus and fixed-iris (or no iris).

The small factor CS mount lenses that I already have don't fit close enough
to the image device to be useful, but they can focus an object at about 1 to
2" away from the front of the lens as an extreme close-up lens.

These SONY XC-777 video cams I have aren't a typical box-type or board
cameras. The body is under 1" square and the body length is about 3.5".
These cameras are considered industrial cams, and when fitted with the
correct lenses, will perform as a normal video camera.

http://www.sony.co.uk/biz/view/ShowP...gory=IntColour

http://assets.sonybiz.net/products/XC-555(img1).jpg

Yep, the threads are going to be metric, and I mentioned 32 tpi as an
indicator to suggest that the threads aren't as fine as 40, or as coarse as
20 tpi.

I don't readily recognize metric thread pitches unless I've got a fastener
in a wrapper marked with the pitch (just far more familiar with inch
threads), and they're not so easy to measure when there are only about 3
crests up against a shoulder or other feature.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Bob La Londe" wrote in message
...

You need a lens not normally available for a mini board camera???

I suspect that the threads may be metric since most of them are made in
the eastern part of the world.

Thanks Dave, I have looked at that adapter page, but overlooked the specs
pdf.

The numerous C and CS lenses that I have don't seem to work with these
cameras, as if the back focal lengths aren't compatible with these SONY
XC-777 cameras.
These cameras don't have an integral mechanical adjustment for the CCD
device.

As I mentioned in another reply, the (C and CS mount) lenses I've tried will
only focus in the extreme close-up range of 1 to 2".

Maybe the problem is that I've tried them with the rear lens elements
positioned too close to the CCD, considering the appearance of the C mount
adapter.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
On Nov 19, 11:07 pm, "Wild_Bill" wrote:
I've had no luck trying to locate information, adapters or lenses for
miniature cameras with NF mount lenses.

The NF designation isn't related to the thread style, but instead is a
miniature version of of C or CS mounts, which instead of being 25mm, the
NF
is 16mm diameter (or maybe a 16.5mm).

Adapters exist to adapt the larger C mount series lenses to NF, but my
preference is to use miniature lenses with the mini cameras.


snippage

Spec for the sony LO-999CMT C-NF adapter shows the thread type.

http://www.ccddirect.com/store/custo...cat=263&page=6
http://ccddirect--documents.com/pdf/lo999cmt.pdf

M17x0.75 external thread

Dave

"Wild_Bill" wrote in message
...
Thanks Bob, the specs I've seen for mini board camera lenses are 12mm x
0.5 and the NF mount threads are likely to be 17mm x 0.75.

The mini board camera lenses might be one option if the focal length would
be compatible.
The board cams I have, have been lent to a friend, or I would have tried
the lenses (although some lenses are superglued in place).
Those lenses sit fairly close to the image device, so they might not have
the optical spacing needed for the SONY XC cam (focal plane, I guess).
I won't know about the board cam lenses until I try a couple of 'em to see
what they'll do.
The majority of them are fixed-focus and fixed-iris (or no iris).

The small factor CS mount lenses that I already have don't fit close
enough to the image device to be useful, but they can focus an object at
about 1 to 2" away from the front of the lens as an extreme close-up lens.

These SONY XC-777 video cams I have aren't a typical box-type or board
cameras. The body is under 1" square and the body length is about 3.5".
These cameras are considered industrial cams, and when fitted with the
correct lenses, will perform as a normal video camera.

http://www.sony.co.uk/biz/view/ShowP...gory=IntColour

http://assets.sonybiz.net/products/XC-555(img1).jpg

Yep, the threads are going to be metric, and I mentioned 32 tpi as an
indicator to suggest that the threads aren't as fine as 40, or as coarse
as 20 tpi.

I don't readily recognize metric thread pitches unless I've got a fastener
in a wrapper marked with the pitch (just far more familiar with inch
threads), and they're not so easy to measure when there are only about 3
crests up against a shoulder or other feature.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


"Bob La Londe" wrote in message
...

You need a lens not normally available for a mini board camera???

I suspect that the threads may be metric since most of them are made in
the eastern part of the world.


You may be able to scrounge some info from the site below.
http://www.allthings.com.au/Catalogue/Lenses/index.html

On Thu, 20 Nov 2008 12:33:28 -0500, "Wild_Bill"
wrote:

Thanks, I've seen Richard's pages, although they seem to be expanded since I
last looked, and this is the first reference I've seen for the NF mount
thread size, 17mm x 0.75.

Richard's truetex camera/microscope adapters page also has some very good
reference links at the end.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


"K Ludger" wrote in message
...


maybe a dig here would yeild something:

http://www.truetex.com/micad.htm


Greetings Bill,
All the optical threads I've done were 55 degree thread form, not the
60 degree we are all famililiar with, even when the pitch was metric.
I believe this is industry standard.
Eric

On 2008-11-20, Wild_Bill wrote:
Thanks Dave, I have looked at that adapter page, but overlooked the specs
pdf.

The numerous C and CS lenses that I have don't seem to work with these
cameras, as if the back focal lengths aren't compatible with these SONY
XC-777 cameras.
These cameras don't have an integral mechanical adjustment for the CCD
device.

As I mentioned in another reply, the (C and CS mount) lenses I've tried will
only focus in the extreme close-up range of 1 to 2".

Maybe the problem is that I've tried them with the rear lens elements
positioned too close to the CCD, considering the appearance of the C mount
adapter.

If the elements are too close to the CCD, you will *never* be
able to focus.

Being only able to focus in extreme close-up range suggests that
the lens is too distant from the CCD.

Just for the fun of it -- stretch a sheet of Kleenex or similar
tissue paper across a frame, and hold the lens in front of it pointed
towards a window (during daytime). Move the lens forward and back until
you get a reasonably sharp image on the tissue. *That* is how far your
lens should be from the CCD.

If the lens you are trying to adapt have larger threads than the
camera does, you really won't be able to get anything other than close
focus.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

All the optical threads I've done were 55 degree thread form, not the
60 degree we are all famililiar with, even when the pitch was metric.
I believe this is industry standard.

What standard? The only application I am aware of would be the ancient RMS
thread used on microscope objectives, which is 55 degree Whitworth.
Virtually everything else is a UN or ISO standard 60 degree form.

On Thu, 20 Nov 2008 22:56:51 -0600, Richard J Kinch
wrote:

All the optical threads I've done were 55 degree thread form, not the
60 degree we are all famililiar with, even when the pitch was metric.
I believe this is industry standard.

What standard? The only application I am aware of would be the ancient RMS
thread used on microscope objectives, which is 55 degree Whitworth.
Virtually everything else is a UN or ISO standard 60 degree form.
My customer told me the 55 degree form was standard. And I made many
different sizes and pitches for them. All 55 degree threads. However,
since I never researched it myself I could only say I believed it was
the standard. It now seems that I am wrong. That's what I like about
folks like you. You know something I don't and pass it along to me.
And, since I have been told two conflicting things it's time I looked
into it myself.
Thanks,
Eric

My customer told me the 55 degree form was standard. And I made many
different sizes and pitches for them. All 55 degree threads. However,
since I never researched it myself I could only say I believed it was
the standard.

I'm not sure what might encompass the broad term "optical threads", but
I am not aware of *any* standard specific to common optical things using
threads, for example camera filters, which seem to be just ordinary ISO
60-degree thread forms in unusual diameter/pitch combinations. If one
looks to well-engineered modern components, for example CCD
instrumentation cameras with threaded mounts like you will find at
http://dalsa.com/, then you will see their drawings indicating metric
ISO thread designations. The few inch threads such a the 1"-32 C-mount
thread are just taken to be vanilla UN specifications, although such
examples are more after-the-fact "gypsy" standards than truly engineered
specifications. I have more to say about this in my
http://www.truetex.com/micad.htm discussion of threads.

I've performed detailed metrology to reverse-engineer hundreds of
specimens of optical assemblies from microscopes, telescopes, and
medical instruments, and they generally are made with fine metric
threads of this sort, as one would expect. If there was some kind of
exceptional adoption of 55 degrees for optical parts in general, I would
think this would be quite remarkable and widely known. But other than
that one bizarre 19th-century Royal Microscopy Society item, I've not
heard of it.

On Fri, 21 Nov 2008 17:13:57 GMT, wrote:

On Thu, 20 Nov 2008 22:56:51 -0600, Richard J Kinch
wrote:

All the optical threads I've done were 55 degree thread form, not the
60 degree we are all famililiar with, even when the pitch was metric.
I believe this is industry standard.

What standard? The only application I am aware of would be the ancient RMS
thread used on microscope objectives, which is 55 degree Whitworth.
Virtually everything else is a UN or ISO standard 60 degree form.
My customer told me the 55 degree form was standard. And I made many
different sizes and pitches for them. All 55 degree threads. However,
since I never researched it myself I could only say I believed it was
the standard. It now seems that I am wrong. That's what I like about
folks like you. You know something I don't and pass it along to me.
And, since I have been told two conflicting things it's time I looked
into it myself.
Thanks,
Eric

At typical optical thread sizes, is a 5 degree difference greater than
machining tolerances?

Thanks DoN for confirming that only focusing in a close-up range suggests
that the lens is too far from the CCD.
I thought that made sense.

I've read about the light from the back of a lens being focused on a piece
of paper or similar material (frosted optical flat, I think), and I will try
this since it would be a good way to label lenses for future reference.

I was pondering that having some metalworking equipment may allow me to
utilize some relatively common lenses for these mini cameras without hacking
up some good Japanese optics.

I expect that aside from aluminum, black Delrin might be useful for various
adapters, if used cautiously to avoid cross-threading or other misalignment.

Some other optical components I have (eyeglass-type monocular lenses etc)
could possibly be adapted to camera lens use for different applications..
microscope or other video conversions.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"DoN. Nichols" wrote in message
...

snippages

Maybe the problem is that I've tried them with the rear lens elements
positioned too close to the CCD, considering the appearance of the C
mount
adapter.

If the elements are too close to the CCD, you will *never* be
able to focus.

Being only able to focus in extreme close-up range suggests that
the lens is too distant from the CCD.

Just for the fun of it -- stretch a sheet of Kleenex or similar
tissue paper across a frame, and hold the lens in front of it pointed
towards a window (during daytime). Move the lens forward and back until
you get a reasonably sharp image on the tissue. *That* is how far your
lens should be from the CCD.

If the lens you are trying to adapt have larger threads than the
camera does, you really won't be able to get anything other than close
focus.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Thanks, there are some cool accessories there, including several that I
didn't know of, such as the adapter for converting video drive iris/DC drive
iris, the Auto Iris Amplifier Box.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"K Ludger" wrote in message
...


You may be able to scrounge some info from the site below.
http://www.allthings.com.au/Catalogue/Lenses/index.html

On 2008-11-22, Wild_Bill wrote:

[ ... ]

I've read about the light from the back of a lens being focused on a piece
of paper or similar material (frosted optical flat, I think), and I will try
this since it would be a good way to label lenses for future reference.

Yes -- ground glass being the standard -- I just mentioned
tissue paper because it is more likely to be ready to hand -- and you
don't need precision for the purpose.

I was pondering that having some metalworking equipment may allow me to
utilize some relatively common lenses for these mini cameras without hacking
up some good Japanese optics.

O.K. You want various forms of short-barrel lenses, so you can
make adaptors the proper length for your focal needs. A good source for
very short barrel lenses would be lenses made for use in enlargers.
(Normal short-barrel lenses were commonly used on extension tubes or
bellows assemblies to allow focusing to infinity.)

I expect that aside from aluminum, black Delrin might be useful for various
adapters, if used cautiously to avoid cross-threading or other misalignment.

Perhaps -- but what I would tend to use for optical mounts would
be a nice free-machining brass. It threads nicely. Thread the ID very
fine where you don't need threads for mounting purposes, and then paint
in flat black paint to minimize reflections on the ID of the adaptor.

Does your lens do metric threads? Almost everything you do with
optics will require metric except some large old camera lenses, and
projection lenses.

Some other optical components I have (eyeglass-type monocular lenses etc)
could possibly be adapted to camera lens use for different applications..
microscope or other video conversions.

O.K. A microscope objective would go about 100mm or is it
160mm) or so away from the CCD for nominal magnification. Closer would
give less magnification, and probably more distortion. Light will be
very low through such lenses.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Yeah, I wouldn't object to using brass, since a whole lot of quality optical
equipment used to be made from brass.

I've seen threading, black paper and multiple grooves cut into inside
surfaces to minimize light reflections, and recently discovered some paper
that sure looks like wet-or-dry sandpaper inside a tube section of a machine
vision camera setup.

I'll be able to cut metric threads, one of my lathes has the 100 & 127T
gears, and the other 2 lathes have other combinations for metric pitches.

I haven't built any optical equipment, but I have some machine vision
assemblies that have illumination capabilities, in that an internal light
source is added to the optical path to light up the (fairly close) target
object. So those illuminators might be helpful where light levels might be a
problem.
One assembly has numbered cross hairs and the other has a miniature LCD
panel in the optical path (but no driver circuit).

Overall, I've acumulated a considerable amount of optical gizmos and odds 'n
ends.. lots of binoculars and some spotting scopes, but also quite a bit of
miniature stuff.

Thanks again,

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"DoN. Nichols" wrote in message
...
On 2008-11-22, Wild_Bill wrote:

[ ... ]

I've read about the light from the back of a lens being focused on a
piece
of paper or similar material (frosted optical flat, I think), and I will
try
this since it would be a good way to label lenses for future reference.

Yes -- ground glass being the standard -- I just mentioned
tissue paper because it is more likely to be ready to hand -- and you
don't need precision for the purpose.

I was pondering that having some metalworking equipment may allow me to
utilize some relatively common lenses for these mini cameras without
hacking
up some good Japanese optics.

O.K. You want various forms of short-barrel lenses, so you can
make adaptors the proper length for your focal needs. A good source for
very short barrel lenses would be lenses made for use in enlargers.
(Normal short-barrel lenses were commonly used on extension tubes or
bellows assemblies to allow focusing to infinity.)

I expect that aside from aluminum, black Delrin might be useful for
various
adapters, if used cautiously to avoid cross-threading or other
misalignment.

Perhaps -- but what I would tend to use for optical mounts would
be a nice free-machining brass. It threads nicely. Thread the ID very
fine where you don't need threads for mounting purposes, and then paint
in flat black paint to minimize reflections on the ID of the adaptor.

Does your lens do metric threads? Almost everything you do with
optics will require metric except some large old camera lenses, and
projection lenses.

Some other optical components I have (eyeglass-type monocular lenses etc)
could possibly be adapted to camera lens use for different applications..
microscope or other video conversions.

O.K. A microscope objective would go about 100mm or is it
160mm) or so away from the CCD for nominal magnification. Closer would
give less magnification, and probably more distortion. Light will be
very low through such lenses.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Fri, 21 Nov 2008 12:56:18 -0600, Richard J Kinch
wrote:

My customer told me the 55 degree form was standard. And I made many
different sizes and pitches for them. All 55 degree threads. However,
since I never researched it myself I could only say I believed it was
the standard.

I'm not sure what might encompass the broad term "optical threads", but
I am not aware of *any* standard specific to common optical things using
threads, for example camera filters, which seem to be just ordinary ISO
60-degree thread forms in unusual diameter/pitch combinations. If one
looks to well-engineered modern components, for example CCD
instrumentation cameras with threaded mounts like you will find at
http://dalsa.com/, then you will see their drawings indicating metric
ISO thread designations. The few inch threads such a the 1"-32 C-mount
thread are just taken to be vanilla UN specifications, although such
examples are more after-the-fact "gypsy" standards than truly engineered
specifications. I have more to say about this in my
http://www.truetex.com/micad.htm discussion of threads.

I've performed detailed metrology to reverse-engineer hundreds of
specimens of optical assemblies from microscopes, telescopes, and
medical instruments, and they generally are made with fine metric
threads of this sort, as one would expect. If there was some kind of
exceptional adoption of 55 degrees for optical parts in general, I would
think this would be quite remarkable and widely known. But other than
that one bizarre 19th-century Royal Microscopy Society item, I've not
heard of it.
Makes me wonder if the engineers who made the drawings assumed they
were all 55 degree. A 55 degree thread will screw into a 60 degree
thread if things are loose enough. Hmm.
Eric

wrote in message
...
On Fri, 21 Nov 2008 12:56:18 -0600, Richard J Kinch
wrote:

My customer told me the 55 degree form was standard. And I made many
different sizes and pitches for them. All 55 degree threads. However,
since I never researched it myself I could only say I believed it was
the standard.

I'm not sure what might encompass the broad term "optical threads", but
I am not aware of *any* standard specific to common optical things using
threads, for example camera filters, which seem to be just ordinary ISO
60-degree thread forms in unusual diameter/pitch combinations. If one
looks to well-engineered modern components, for example CCD
instrumentation cameras with threaded mounts like you will find at
http://dalsa.com/, then you will see their drawings indicating metric
ISO thread designations. The few inch threads such a the 1"-32 C-mount
thread are just taken to be vanilla UN specifications, although such
examples are more after-the-fact "gypsy" standards than truly engineered
specifications. I have more to say about this in my
http://www.truetex.com/micad.htm discussion of threads.

I've performed detailed metrology to reverse-engineer hundreds of
specimens of optical assemblies from microscopes, telescopes, and
medical instruments, and they generally are made with fine metric
threads of this sort, as one would expect. If there was some kind of
exceptional adoption of 55 degrees for optical parts in general, I would
think this would be quite remarkable and widely known. But other than
that one bizarre 19th-century Royal Microscopy Society item, I've not
heard of it.
Makes me wonder if the engineers who made the drawings assumed they
were all 55 degree. A 55 degree thread will screw into a 60 degree
thread if things are loose enough. Hmm.
Eric

From memory, not from sources: I believe old optical threads were Imperial,
not metric, and that they were based on the 55-degree Whitworth form,
without the fancy roots. The fine ones were usually hand-chased, not cut on
a screwcutting lathe.

That was true at least until the 1920s, I believe, and European optical
instruments often were made with a metric-equivalent value of Imperial
values for thread pitch and diameters.

My uncle did a lot of that work and I thought I had his old telescope books
around, but I can't come up with them.

--
Ed Huntress

Ed Huntress wrote:

From memory, not from sources: I believe old optical threads were Imperial,
not metric, and that they were based on the 55-degree Whitworth form,
without the fancy roots. The fine ones were usually hand-chased, not cut on
a screwcutting lathe.

My uncle did a lot of that work


Ed,

How about a lesson in thread chasing?


Kevin Gallimore

"axolotl" wrote in message
...
Ed Huntress wrote:

From memory, not from sources: I believe old optical threads were
Imperial, not metric, and that they were based on the 55-degree Whitworth
form, without the fancy roots. The fine ones were usually hand-chased,
not cut on a screwcutting lathe.

My uncle did a lot of that work


Ed,

How about a lesson in thread chasing?


Kevin Gallimore

Sure. Teach away. I'd be glad to learn. d8-)

My uncle was very good at it. 'Made all his own chasing tools. I tried it on
a piece of aluminum barstock, soon after I got my lathe, and I finally got
one to come out good -- after three or four tries.

You need to have a good sense of timing. If you're too slow, you wind up
with a few closely-spaced, shallow grooves. If you're too fast, you can wind
up with a double-lead thread.

Do you understand the basic idea? The tool is a freehand turning tool, which
you hold over a tool support much like the one on a wood-turning lathe. The
tool looks like a flat chisel on the end, but with four or five teeth, each
shaped like a single-point threading tool, only it can be simpler, without
any rake.

You start moving the tool along the work, in the direction of the thread you
want to cut, and then you plunge the tool into the work while you're moving
it lengthwise along the lathe bed. If you get it right, it cuts a
single-lead thread and it self-feeds after the first revolution of the work.
You'll need to make a few passes to cut the thread to full depth, but after
the first pass, the tool follows the previous cut.

It's a bit of an art but people who specialized in it got it right every
time.

--
Ed Huntress

On Sat, 22 Nov 2008 20:36:49 -0500, "Ed Huntress"
wrote:


"axolotl" wrote in message
...
Ed Huntress wrote:

From memory, not from sources: I believe old optical threads were
Imperial, not metric, and that they were based on the 55-degree Whitworth
form, without the fancy roots. The fine ones were usually hand-chased,
not cut on a screwcutting lathe.

My uncle did a lot of that work


Ed,

How about a lesson in thread chasing?


Kevin Gallimore

Sure. Teach away. I'd be glad to learn. d8-)

My uncle was very good at it. 'Made all his own chasing tools. I tried it on
a piece of aluminum barstock, soon after I got my lathe, and I finally got
one to come out good -- after three or four tries.

You need to have a good sense of timing. If you're too slow, you wind up
with a few closely-spaced, shallow grooves. If you're too fast, you can wind
up with a double-lead thread.

Do you understand the basic idea? The tool is a freehand turning tool, which
you hold over a tool support much like the one on a wood-turning lathe. The
tool looks like a flat chisel on the end, but with four or five teeth, each
shaped like a single-point threading tool, only it can be simpler, without
any rake.

You start moving the tool along the work, in the direction of the thread you
want to cut, and then you plunge the tool into the work while you're moving
it lengthwise along the lathe bed. If you get it right, it cuts a
single-lead thread and it self-feeds after the first revolution of the work.
You'll need to make a few passes to cut the thread to full depth, but after
the first pass, the tool follows the previous cut.

It's a bit of an art but people who specialized in it got it right every
time.

--
Ed Huntress


Greetings Ed,
I've cut thousands of threads of all sorts of different pitches and
design. But I have never hand chased a thread. Horoligists apparently
hand chase threads sometimes. The smallest thread I have single
pointed is 0-80. I tried 00-96 but couldn't make it work. Too much
deflection of the screw. Now, after reading your post, I just have to
learn how to hand chase threads. I know it will come in handy for tiny
threads.
Thanks,
Eric

wrote in message
...
On Sat, 22 Nov 2008 20:36:49 -0500, "Ed Huntress"
wrote:


"axolotl" wrote in message
...
Ed Huntress wrote:

From memory, not from sources: I believe old optical threads were
Imperial, not metric, and that they were based on the 55-degree
Whitworth
form, without the fancy roots. The fine ones were usually hand-chased,
not cut on a screwcutting lathe.

My uncle did a lot of that work


Ed,

How about a lesson in thread chasing?


Kevin Gallimore

Sure. Teach away. I'd be glad to learn. d8-)

My uncle was very good at it. 'Made all his own chasing tools. I tried it
on
a piece of aluminum barstock, soon after I got my lathe, and I finally got
one to come out good -- after three or four tries.

You need to have a good sense of timing. If you're too slow, you wind up
with a few closely-spaced, shallow grooves. If you're too fast, you can
wind
up with a double-lead thread.

Do you understand the basic idea? The tool is a freehand turning tool,
which
you hold over a tool support much like the one on a wood-turning lathe.
The
tool looks like a flat chisel on the end, but with four or five teeth,
each
shaped like a single-point threading tool, only it can be simpler, without
any rake.

You start moving the tool along the work, in the direction of the thread
you
want to cut, and then you plunge the tool into the work while you're
moving
it lengthwise along the lathe bed. If you get it right, it cuts a
single-lead thread and it self-feeds after the first revolution of the
work.
You'll need to make a few passes to cut the thread to full depth, but
after
the first pass, the tool follows the previous cut.

It's a bit of an art but people who specialized in it got it right every
time.

--
Ed Huntress


Greetings Ed,
I've cut thousands of threads of all sorts of different pitches and
design. But I have never hand chased a thread. Horoligists apparently
hand chase threads sometimes. The smallest thread I have single
pointed is 0-80. I tried 00-96 but couldn't make it work. Too much
deflection of the screw. Now, after reading your post, I just have to
learn how to hand chase threads. I know it will come in handy for tiny
threads.
Thanks,
Eric

I see that there's a lot of info on hand-chasing threads in wood on the Web,
and some on the subject in metal. I'll bet that with some of that info and
some practice you'd find that it isn't hard.

The good thing is that there is some latitude in the starting speed with
which you move the tool, because the second and following teeth tend to
follow the start, and they push the first tooth along once they get a grip.
So it's not as magical as it may sound. It just takes some practice.

My uncle (a shop teacher) worked with a big astronomy club full of telescope
makers back in the '30s, helping them with machining for their hobby, and he
got quite good at it. He told me that I should learn because it would come
in handy. I can't say it has, but I don't work with optics or clocks.

I thought a lot about the business of making the cutters for extremely fine
threads, and it seems to me that's the hard part. If you have the right
pitch available on your lathe you might be able to rig a boring-bar-type
flycutter, between centers, with the blank tool mounted in the toolholder,
and just take tiny nicks with the flycutter to mark the positions for filing
in the chasing tool. Then finish it off with a file. It probably requires
the very finest of Swiss-pattern jeweler's files for the fine ones, working
with magnification.

My uncle told me that the keepers (they must have a name but I don't know
what it is) for individual elements in a refractive telescope are typically
mounted on a mandrel for machining and threading, because they're very thin
and fairly large in diameter relative to the thread length. He also
mentioned that a lot of threads on old telescopes were *******s, because the
machinist would cut the outside thread and then bend the end of the tool
over to cut the matching internal thread. And they worried more about
getting a proper fit than about actual thread pitch.

That must have taken a lot of finesse. I got interested in making clock jigs
at one time, after I met Dick Moore and read his early books, and my
interests went in the direction of precision positioning rather than making
threads.

Good luck and give us a report when you get a chance to try it.

--
Ed Huntress

Ed Huntress writes:

That must have taken a lot of finesse.

That's all a wonderful bit of lore, but I don't think anything has been
hand-chased in optics since H. G. Wells and the Victorian era. I don't see
how it could be anything but a degraded version of single-point threading,
something to resort to if you didn't have an engine lathe. Single-point
threading is especially critical for thin tubes, since the side load is
minimized.

On 2008-11-22, Wild_Bill wrote:
Yeah, I wouldn't object to using brass, since a whole lot of quality optical
equipment used to be made from brass.

It is a lot more free from galling than aluminum (unless you do
a good job of anodize after threading. :-)

I've seen threading, black paper and multiple grooves cut into inside
surfaces to minimize light reflections, and recently discovered some paper
that sure looks like wet-or-dry sandpaper inside a tube section of a machine
vision camera setup.

Interesting. That should work nicely -- as long as the grit
does not get loose and rattle against the lenses. :-)

Black paper has more reflection than the threaded and painted
surfaces.

I'll be able to cut metric threads, one of my lathes has the 100 & 127T
gears, and the other 2 lathes have other combinations for metric pitches.

Beware of threading to a shoulder, however. With conversion
gears such as the 100/127 pair you won't be able to use the half-nuts
and threading dial -- unless you can cut full depth in a single pass --
which *might* be possible with the finer threads used for filter mounts
and such.

I haven't built any optical equipment, but I have some machine vision
assemblies that have illumination capabilities, in that an internal light
source is added to the optical path to light up the (fairly close) target
object. So those illuminators might be helpful where light levels might be a
problem.
One assembly has numbered cross hairs and the other has a miniature LCD
panel in the optical path (but no driver circuit).

Nice.

Overall, I've acumulated a considerable amount of optical gizmos and odds 'n
ends.. lots of binoculars and some spotting scopes, but also quite a bit of
miniature stuff.

If you want some small ground glass for lens testing, and have
some spare microscope slides (1"x3" IIRC) you can rub it back and forth
on a nice flat whetstone to make the ground surface on one side. The
finer the grit the more transparent it tends to be, so experiment for a
while with broken fragments to see what works best for you.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Hi DoN, one of my concerns about using aluminum was that I was sure that the
parts would need to be anodized, which I've read a lot about, but haven't
done (any anodizing).
I've had to disassemble properly threaded and some nasty cross-threaded
binocular parts that weren't anodized, and it's easy to see that anodizing
would very likely have prevented most of the problems.

A thick gooey grease or beeswax makes re-assembly much easier, but getting
the grease on the optics would be bad.
The grease that I've used (sparingly) is a thick synthetic non-silicone lube
for automotive disk brake caliper sliding surfaces/parts. I have looked into
the special lubricants that optical equipment manufacturers use, but haven't
actually tracked any down.

I wouldn't use this lube on anything critical or valuable, since I don't
know what it might exude as far as residue creeping about within.

I can't recall ever seeing thread problems with brass parts, which indicates
it's superiority for use especially where fine threads are involved.

As I suggested in my original post, I expect to be threading with a hand
crank since the majority of the parts only require a very short threaded
section, usually adjacent to a shoulder.

Your suggestion for imrovising ground glass is a real gem, it had completely
escaped me to consider making some controlled scratches.. doi-ee.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"DoN. Nichols" wrote in message
...
On 2008-11-22, Wild_Bill wrote:
Yeah, I wouldn't object to using brass, since a whole lot of quality
optical
equipment used to be made from brass.

It is a lot more free from galling than aluminum (unless you do
a good job of anodize after threading. :-)

I've seen threading, black paper and multiple grooves cut into inside
surfaces to minimize light reflections, and recently discovered some
paper
that sure looks like wet-or-dry sandpaper inside a tube section of a
machine
vision camera setup.

Interesting. That should work nicely -- as long as the grit
does not get loose and rattle against the lenses. :-)

Black paper has more reflection than the threaded and painted
surfaces.

I'll be able to cut metric threads, one of my lathes has the 100 & 127T
gears, and the other 2 lathes have other combinations for metric pitches.

Beware of threading to a shoulder, however. With conversion
gears such as the 100/127 pair you won't be able to use the half-nuts
and threading dial -- unless you can cut full depth in a single pass --
which *might* be possible with the finer threads used for filter mounts
and such.

I haven't built any optical equipment, but I have some machine vision
assemblies that have illumination capabilities, in that an internal light
source is added to the optical path to light up the (fairly close) target
object. So those illuminators might be helpful where light levels might
be a
problem.
One assembly has numbered cross hairs and the other has a miniature LCD
panel in the optical path (but no driver circuit).

Nice.

Overall, I've acumulated a considerable amount of optical gizmos and odds
'n
ends.. lots of binoculars and some spotting scopes, but also quite a bit
of
miniature stuff.

If you want some small ground glass for lens testing, and have
some spare microscope slides (1"x3" IIRC) you can rub it back and forth
on a nice flat whetstone to make the ground surface on one side. The
finer the grit the more transparent it tends to be, so experiment for a
while with broken fragments to see what works best for you.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Wild_Bill writes:

A thick gooey grease or beeswax makes re-assembly much easier, but
getting the grease on the optics would be bad.

On the contrary, sealed optical assemblies are often gobbed all over
inside with grease inside to trap dust on a flypaper principle. Not on
the glass, of course.

Bare aluminum-to-aluminum threads work fine if there is no interference.
If they bind or gall, you're likely not honoring the thread allowances
in your fabrication. Or approximating a metric pitch on an inch lathe
versus a mating part that is true metric.

The grease that I've used (sparingly) is a thick synthetic
non-silicone lube for automotive disk brake caliper sliding
surfaces/parts. I have looked into the special lubricants that optical
equipment manufacturers use, but haven't actually tracked any down.

The "special lubricants" are most commonly pure ordinary white petroleum
grease, sometimes disguised with the names petrolatum, petroleum jelly,
or Vaseline. Wetted with naphtha to make a brushable grease paint.
Upgraded to high-temp bearing grease (lithium soap, etc) from the auto
parts store if things might get hot.

Once I used my pocket ChapStick when in the field with nothing else
handy, but don't tell my customer.

Hi Richard, thanks for the comments and the in-depth detailed webpages.

I've not encountered amounts of internal grease to trap dust, but then my
experience is mainly consumer and a few military binoculars/optics, and a
few pieces of industrial optical equipment. Encountering unexpected grease
could get messy.

The non-anodized aluminum thread issues that I've encountered were
manufactured items (pre-and-post WWII to present technology USA, Japan and
Germany), some which appear to have been disassembled by previous owners and
probably messed up the threads when they tried to reassemble the parts
incorrectly.

I haven't started making optical fittings yet, which is why I'm asking
questions about how to go about it (the purpose of the thread).

I've not used ChapStick on threads, but I've used pure lanolin (in a plastic
tube from Enco) which is a thick paste consistency when cold, but gets thin
with heat, to the point that it may run when moderately hot. Lanolin is a
fairly good cutting lubricant, too, FWIW.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Richard J Kinch" wrote in message
. ..
Wild_Bill writes:

A thick gooey grease or beeswax makes re-assembly much easier, but
getting the grease on the optics would be bad.

On the contrary, sealed optical assemblies are often gobbed all over
inside with grease inside to trap dust on a flypaper principle. Not on
the glass, of course.

Bare aluminum-to-aluminum threads work fine if there is no interference.
If they bind or gall, you're likely not honoring the thread allowances
in your fabrication. Or approximating a metric pitch on an inch lathe
versus a mating part that is true metric.

The grease that I've used (sparingly) is a thick synthetic
non-silicone lube for automotive disk brake caliper sliding
surfaces/parts. I have looked into the special lubricants that optical
equipment manufacturers use, but haven't actually tracked any down.

The "special lubricants" are most commonly pure ordinary white petroleum
grease, sometimes disguised with the names petrolatum, petroleum jelly,
or Vaseline. Wetted with naphtha to make a brushable grease paint.
Upgraded to high-temp bearing grease (lithium soap, etc) from the auto
parts store if things might get hot.

Once I used my pocket ChapStick when in the field with nothing else
handy, but don't tell my customer.

On Sat, 22 Nov 2008 15:26:58 -0500, "Ed Huntress"
wrote:




From memory, not from sources: I believe old optical threads were Imperial,
not metric, and that they were based on the 55-degree Whitworth form,
without the fancy roots. The fine ones were usually hand-chased, not cut on
a screwcutting lathe.

That was true at least until the 1920s, I believe, and European optical
instruments often were made with a metric-equivalent value of Imperial
values for thread pitch and diameters.

My uncle did a lot of that work and I thought I had his old telescope books
around, but I can't come up with them.

finally a light came on.
I recall that Newnes screw thread tables had a section on old
photographic threads.

Royal Photographic Society Screw Thread (Whitworth Form)
diameter in inches : threads per inch : core diameter in inches
1 : 24 : 0.9466
1 1/4: 24: 1.1966
1 3/8: 24:1.3216
1 1/2: 24:1.4466
1 5/8: 24:1.5716
1 3/4: 24 :1.6966
1 7/8: 24: 1.8216
2 : 24: 1.9466
2 1/4: 24 : 2.1966
2 1/2: 24 : 2.4466
3 : 24 : 2.9466
3 1/2: 12 : 3.3933
4 : 12 : 3.8933
5 : 12 : 4.8933
for screws under 1 inch adopt the Royal Microscopical Societies
Standard.

so...
Royal Microscopical Society Screw Thread (Whitworth Form)
screw thread for objective
pitch 36 threads per inch = 0.02778in approximately
(= 0.7056mm) length of thread , 0.125in (= 0.175mm)
full diameter 0.7982" max or 20.274mm max. 0.7952" or 20.198mm
minimum.
effective diameter 0.7804" or 19.822mm.
core diameter 0.7626" or 19.370mm.

screw thread for nose piece
form pitch as for the objective screw. length of thread not to be less
than 0.125" (3.175mm)
full diameter 0.8" or 20.320mm minimum
effective diameter 0.7822" or 19.868mm
core diameter 0.7644" or 19.416mm minimum 0.7674" or 19.492mm maximum.

that all is probably not one ounce of help in the problem at hand but
it gets rid of a dark corner in the discussion.

Stealth Pilot
(E&OE = errors and omissions excepted)

"Richard J Kinch" wrote in message
. ..
Ed Huntress writes:

That must have taken a lot of finesse.

That's all a wonderful bit of lore, but I don't think anything has been
hand-chased in optics since H. G. Wells and the Victorian era. I don't
see
how it could be anything but a degraded version of single-point threading,
something to resort to if you didn't have an engine lathe. Single-point
threading is especially critical for thin tubes, since the side load is
minimized.

Amateur telescope makers used the method at least into the '50s. If you
haven't tried it, don't knock it.

--
Ed Huntress

"Richard J Kinch" wrote in message
. ..
Ed Huntress writes:

That must have taken a lot of finesse.

That's all a wonderful bit of lore, but I don't think anything has been
hand-chased in optics since H. G. Wells and the Victorian era. I don't
see
how it could be anything but a degraded version of single-point threading,
something to resort to if you didn't have an engine lathe. Single-point
threading is especially critical for thin tubes, since the side load is
minimized.

Richard, I thought you might be interested in this brief account, from 1972:

http://www.brayebrookobservatory.org...ving_obit.html

=================================================

To my amazement he mounted the sleeve in a self centering 3 jaw scroll chuck
on one of his Boxford lathes, and hand chased a 100 tpi thread on the brass
ring's OD. He then removed the sleeve from the chuck, fitted a purpose
turned steel collar with a shouldered 4-inch bore, and located the PA circle
within it. He then hand chased an internal 100 tpi screw thread, to match
that turned on the brass ring. The PA circle was then screwed onto the brass
ring, aligned to suit the opposing verniers so that the micrometer would be
horizontal at PA 90° / 270°, and a 1/64-inch dia. hole drilled through the
thread and a little silver pin tapped into it so the PA circle was locked in
place. An amazing job calling for the most consummate skill, performed by a
man in his mid 70's with chronic arthritis, perched on a bar stool at his
favourite lathe, and all done in less than an hour.

=================================================

I have several of the books on telescope making that MIT Press published in
the '20s and '30s, and they describe hand-chasing threads for eyepieces and
similar devices. One of the Scientific American telescope books, which I
bought in the late '70s, (but which was originally published, I think, in
the '40s) also talks about it.

If someone here has a copy of Guy Lautard's _The Machinist's Bedside
Reader_, he apparently discusses it there, but I don't know if he's talking
about original threads or cleaning up old ones. I haven't read it.

Historically, hand-chasing was used in a variety of industries until well
after 1900. The "brass-finisher's lathes" and horological lathes then made
for precision work had a fairly common type of thread-following attachment,
similar to the ones used on early model Unimats, which eventually replaced
hand-chasing in production and in much of industry. But skilled lathe hands
still hand-chased into the '20s or so, until change-gear lathes had crept
into all corners of toolmaking and prototype making, because one might find
his set of follower-type thread-chasing attachments didn't include the right
pitch for the job at hand. A set of hand thread-chasing tools (sometimes
called "comb tools") was far cheaper than a set of followers.

Hand-chasing apparently produces very clean and smooth threads in brass,
which is the material that was most used for optical work like this. As I
mentioned, skilled amateurs were using the method for decades after it was
replaced in industry.

--
Ed Huntress

On Sun, 23 Nov 2008 02:50:37 GMT, wrote:

snip
Now, after reading your post, I just have to
learn how to hand chase threads. I know it will come in
handy for tiny threads.
Thanks,
Eric

You can find some info on thread chasing in old books. "The
Complete Practical Machinist" by Joshua Rose 1895 has some
info. You can get it off the net he

http://www.archive.org/details/compl...tica00roseuoft

I would download the djvu version myself (which I have and
it is excellent!). Click on the "All files: HTTP" in the
left column for a directory listing. Otherwise you will get
the djvu stream for viewing with a browser plugin. Then save
the djvu file locally. It is ~19mb, but the detail is good.
Pages 104-107 in particular if you have/get this book (note
that the thumbnail numbers and page numbers don't match
exactly).

The following program works really well for viewing said
file:

http://windjview.sourceforge.net/

"WinDjView is a fast, compact and powerful DjVu viewer for
Windows with continuous scrolling and advanced printing
options. It uses the free DjVuLibre library to decode DjVu
documents. DjVu is a web-centric format and software
platform for distributing documents and images."

This program will blow the doors off any pdf/acrobat viewer
that I've messed around with...

Poke around in the Archive site, there are several more old
books in this genre worth getting. On the same Archive page
for Complete Practical Machinist try clicking on the
"Subject: Machine-Tools" link for starters.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

Ed Huntress writes:

Amateur telescope makers used the method at least into the '50s. If you
haven't tried it, don't knock it.

I don't knock it; there are appropriate uses for hobby or historical
purposes. I suppose those ATMs just didn't have a proper engine lathe for
fine threading. Maybe they spent all their available time skiving leather
belts to their steam engines to run whatever they had.

I hand-scraped my worn-out Bridgeport back to new, so its not like I'm
opposed to improvising with primitive techniques, when more modern tools
are not at hand.

On 2008-11-23, Wild_Bill wrote:
Hi DoN, one of my concerns about using aluminum was that I was sure that the
parts would need to be anodized, which I've read a lot about, but haven't
done (any anodizing).
I've had to disassemble properly threaded and some nasty cross-threaded
binocular parts that weren't anodized, and it's easy to see that anodizing
would very likely have prevented most of the problems.

And some of the threads in binoculars (the eyepiece individual
focusing ones at least) seem to be rather coarse acme style threads with
a thick gray-silver grease in them.

A thick gooey grease or beeswax makes re-assembly much easier, but getting
the grease on the optics would be bad.

Depending on whether it could be removed with a solvent and
without mechanical scrubbing.

The grease that I've used (sparingly) is a thick synthetic non-silicone lube
for automotive disk brake caliper sliding surfaces/parts.

Hmm ... I'll have to look into that.

I have looked into
the special lubricants that optical equipment manufacturers use, but haven't
actually tracked any down.

O.K. Let me know if you do -- and where. I would like to clean
and re-grease the focusing threads on my 500mm f8 reflex Nikkor (cat
lens).

I wouldn't use this lube on anything critical or valuable, since I don't
know what it might exude as far as residue creeping about within.

Indeed -- though a lube which is designed for the temperatures
sometimes found on brake calipers would probably not give any problems
on that line.

I can't recall ever seeing thread problems with brass parts, which indicates
it's superiority for use especially where fine threads are involved.

It is still *possible* to cross-thread them, but you can tell by
feel a lot sooner -- soon enough to prevent significant damage.

As I suggested in my original post, I expect to be threading with a hand
crank since the majority of the parts only require a very short threaded
section, usually adjacent to a shoulder.

O.K. I had forgotten that.

When I need to cut metric threads, I go to my Compact-5/CNC and
simply throw the switch into metric mode. :-)

I do have the conversion gear set for my 12x24" Clausing (if a
5900 set will properly fit on a 5400 series lathe -- not tried yet), but
until I need to thread something too big for the Compact-5, I'll stick
with it for metric threads. :-)

Your suggestion for imrovising ground glass is a real gem, it had completely
escaped me to consider making some controlled scratches.. doi-ee.

It took me some tries to get one opaque enough for the purpose.
The first tries were too fine and I could see through the glass instead
of just seeing the image on the ground glass.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

About a year ago, I was seriously engrossed in researching and buying
binoculars and some of the various other optic stuff, and I was finding some
solidified grey residue in the seized eyepiece focus threads and also the
center focus parts of some binocular models.

I knew it had been a lubricant when the devices were manufactured 50-70
years ago in Japan or Germany, but it had completely dried out leaving a
solid thread-locking mess, very similar to dried grey automotive primer.
The only effective solvent for the stuff was lacquer thinner, and not just a
little, but putting the parts in a closed container with the threads
submerged in thinner for several days.
I suspect that this lube was originally something like the old white lead.

One of the resources I found by searching for binocular lubricants and
greases was these europa forum archives
http://www.europa.com/~telscope/listpr50.txt

http://www.europa.com/~telscope/listp250.txt

http://www.europa.com/~telscope/binoc_list.txt

Practically every aspect of binocular construction, design flaws, service
and repair are covered in the many very long text files.
These archives were shown in the results of Goog searches.

One binocular that I bought appeared to have something like the old
non-drying Permatex sealer on all of the moving parts, I assume it was put
there by someone who was uncertain what type of grease to use after
disassembly. What a mess.

From what I could determine, a few of the characteristics for good
lubricants are stable consistency over a wide temperature range, not
out-gassing? (vapor releasing) and anti-bacterial to combat fungus.
FWIW, fungus will actually etch glass, much like squashed bugs on a
windshield do.

That aoto caliper lube I referred to may not have any of the characteristics
of a proper lube for optical equipment, but I tried some and will find out
eventually.
The goop works very well for some machine purposes. I use it in several
machines with very positive results, such as drill press quill rack and
pinion. It's thicker than, but sticky like Karo syrup, so it keeps pulling
itself back 'n forth between the 2 mating parts, and doesn't just squeeze
out to the sides like many greases do.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"DoN. Nichols" wrote in message
...
On 2008-11-23, Wild_Bill wrote:
Hi DoN, one of my concerns about using aluminum was that I was sure that
the
parts would need to be anodized, which I've read a lot about, but haven't
done (any anodizing).
I've had to disassemble properly threaded and some nasty cross-threaded
binocular parts that weren't anodized, and it's easy to see that
anodizing
would very likely have prevented most of the problems.

And some of the threads in binoculars (the eyepiece individual
focusing ones at least) seem to be rather coarse acme style threads with
a thick gray-silver grease in them.

A thick gooey grease or beeswax makes re-assembly much easier, but
getting
the grease on the optics would be bad.

Depending on whether it could be removed with a solvent and
without mechanical scrubbing.

The grease that I've used (sparingly) is a thick synthetic non-silicone
lube
for automotive disk brake caliper sliding surfaces/parts.

Hmm ... I'll have to look into that.

I have looked
into
the special lubricants that optical equipment manufacturers use, but
haven't
actually tracked any down.

O.K. Let me know if you do -- and where. I would like to clean
and re-grease the focusing threads on my 500mm f8 reflex Nikkor (cat
lens).

I wouldn't use this lube on anything critical or valuable, since I don't
know what it might exude as far as residue creeping about within.

Indeed -- though a lube which is designed for the temperatures
sometimes found on brake calipers would probably not give any problems
on that line.

I can't recall ever seeing thread problems with brass parts, which
indicates
it's superiority for use especially where fine threads are involved.

It is still *possible* to cross-thread them, but you can tell by
feel a lot sooner -- soon enough to prevent significant damage.

As I suggested in my original post, I expect to be threading with a hand
crank since the majority of the parts only require a very short threaded
section, usually adjacent to a shoulder.

O.K. I had forgotten that.

When I need to cut metric threads, I go to my Compact-5/CNC and
simply throw the switch into metric mode. :-)

I do have the conversion gear set for my 12x24" Clausing (if a
5900 set will properly fit on a 5400 series lathe -- not tried yet), but
until I need to thread something too big for the Compact-5, I'll stick
with it for metric threads. :-)

Your suggestion for imrovising ground glass is a real gem, it had
completely
escaped me to consider making some controlled scratches.. doi-ee.

It took me some tries to get one opaque enough for the purpose.
The first tries were too fine and I could see through the glass instead
of just seeing the image on the ground glass.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Sun, 23 Nov 2008 21:01:55 -0500, "Wild_Bill"
wrote:



From what I could determine, a few of the characteristics for good
lubricants are stable consistency over a wide temperature range, not
out-gassing? (vapor releasing) and anti-bacterial to combat fungus.
FWIW, fungus will actually etch glass, much like squashed bugs on a
windshield do.


Dunno about anti-fungal, but vacuum grease meets the other two
criteria and I've used it on optical components where a very thick
grease seemed desirable. Permatex makes a clear synthetic grease that
has a lighter consistency than vacuum grease and is quite stable, but
I don't about its tendency to outgas. It's much less expensive than
vacuum grease.

--
Ned Simmons

On Nov 23, 9:22*pm, Ned Simmons wrote:
On Sun, 23 Nov 2008 21:01:55 -0500, "Wild_Bill"

wrote:

From what I could determine, a few of the characteristics for good
lubricants are stable consistency over a wide temperature range, not
out-gassing? (vapor releasing) and anti-bacterial to combat fungus.
FWIW, fungus will actually etch glass, much like squashed bugs on a
windshield do.

Dunno about anti-fungal, but vacuum grease meets the other two
criteria and I've used it on optical components where a very thick
grease seemed desirable. Permatex makes a clear synthetic grease that
has a lighter consistency than vacuum grease and is quite stable, but
I don't about its tendency to outgas. It's much less expensive than
vacuum grease.

--
Ned Simmons

Usually the vacuum grease is some sort of silicone-based stuff. Not
sure how it is in cold weather, like for binocular components, but it
should work as long as the mating pieces don't move too fast.

Most of the old camera lenses I've had apart had some kind of
yellowish stuff packed in them, resembled beeswax with something for a
softener added. Whatever it was, it had dried out/gone away, and the
stuff was back to resembling hard beeswax. You don't really want a
totally friction free movement with a camera lens, you want it to stay
put where you leave it, but these were ridiculous.

I've been using, for a number of years, a synthetic lube gel by Syntec
for all sorts of stuff. I started out using it on plastic/metal gear
sets, like in laser printers, killed the squeaks. VCRs and CD/DVD
drives, too. It's good for a lot of things, including helical
focusing mounts. It doesn't seem to have a lot of temperature
sensitivity, either. I used to get it from Radio Shack, they
discontinued it, naturally, then True Value had it by the pound can.
True Value died here, so the last point of supply is Harbor Freight.
Used to be a couple of bucks a tube, now it's up to about $4 for about
4 oz. It only takes a small smear to get the job done, not everything
has to be packed like a wheel bearing, after all. Useful for gun
triggers, too, anywhere you have a precision mechanism with relatively
high forces involved in small areas. Doesn't seem to accumulate dust,
that was one of the advertising points. The stuff is colorless,
transparent in thin layers, so a lot better than moly paste or
graphite greases for stuff that gets handled. Works well on car
electric window and lock motors, too, even sub-zero.

Stan

On Sat, 22 Nov 2008 22:29:19 -0500, "Ed Huntress"
wrote:


wrote in message
...
On Sat, 22 Nov 2008 20:36:49 -0500, "Ed Huntress"
wrote:


"axolotl" wrote in message
...
Ed Huntress wrote:

From memory, not from sources: I believe old optical threads were
Imperial, not metric, and that they were based on the 55-degree
Whitworth
form, without the fancy roots. The fine ones were usually hand-chased,
not cut on a screwcutting lathe.

My uncle did a lot of that work


Ed,

How about a lesson in thread chasing?


Kevin Gallimore

Sure. Teach away. I'd be glad to learn. d8-)

My uncle was very good at it. 'Made all his own chasing tools. I tried it
on
a piece of aluminum barstock, soon after I got my lathe, and I finally got
one to come out good -- after three or four tries.

You need to have a good sense of timing. If you're too slow, you wind up
with a few closely-spaced, shallow grooves. If you're too fast, you can
wind
up with a double-lead thread.

Do you understand the basic idea? The tool is a freehand turning tool,
which
you hold over a tool support much like the one on a wood-turning lathe.
The
tool looks like a flat chisel on the end, but with four or five teeth,
each
shaped like a single-point threading tool, only it can be simpler, without
any rake.

You start moving the tool along the work, in the direction of the thread
you
want to cut, and then you plunge the tool into the work while you're
moving
it lengthwise along the lathe bed. If you get it right, it cuts a
single-lead thread and it self-feeds after the first revolution of the
work.
You'll need to make a few passes to cut the thread to full depth, but
after
the first pass, the tool follows the previous cut.

It's a bit of an art but people who specialized in it got it right every
time.

--
Ed Huntress


Greetings Ed,
I've cut thousands of threads of all sorts of different pitches and
design. But I have never hand chased a thread. Horoligists apparently
hand chase threads sometimes. The smallest thread I have single
pointed is 0-80. I tried 00-96 but couldn't make it work. Too much
deflection of the screw. Now, after reading your post, I just have to
learn how to hand chase threads. I know it will come in handy for tiny
threads.
Thanks,
Eric

I see that there's a lot of info on hand-chasing threads in wood on the Web,
and some on the subject in metal. I'll bet that with some of that info and
some practice you'd find that it isn't hard.

The good thing is that there is some latitude in the starting speed with
which you move the tool, because the second and following teeth tend to
follow the start, and they push the first tooth along once they get a grip.
So it's not as magical as it may sound. It just takes some practice.

My uncle (a shop teacher) worked with a big astronomy club full of telescope
makers back in the '30s, helping them with machining for their hobby, and he
got quite good at it. He told me that I should learn because it would come
in handy. I can't say it has, but I don't work with optics or clocks.

I thought a lot about the business of making the cutters for extremely fine
threads, and it seems to me that's the hard part. If you have the right
pitch available on your lathe you might be able to rig a boring-bar-type
flycutter, between centers, with the blank tool mounted in the toolholder,
and just take tiny nicks with the flycutter to mark the positions for filing
in the chasing tool. Then finish it off with a file. It probably requires
the very finest of Swiss-pattern jeweler's files for the fine ones, working
with magnification.

My uncle told me that the keepers (they must have a name but I don't know
what it is) for individual elements in a refractive telescope are typically
mounted on a mandrel for machining and threading, because they're very thin
and fairly large in diameter relative to the thread length. He also
mentioned that a lot of threads on old telescopes were *******s, because the
machinist would cut the outside thread and then bend the end of the tool
over to cut the matching internal thread. And they worried more about
getting a proper fit than about actual thread pitch.

That must have taken a lot of finesse. I got interested in making clock jigs
at one time, after I met Dick Moore and read his early books, and my
interests went in the direction of precision positioning rather than making
threads.

Good luck and give us a report when you get a chance to try it.

--
Ed Huntress


Thanks Ed. I will post results. Hand chased threads have started to
really rouse my curiosity.
Eric