Home Made Registration Punch and Carrier?

Registration punches and carriers for projection (enlarging) 8x10
and also for contact printing 8x10 and larger.

All I've found so far are very large registration punches intended for
nonphotographic printing, or some dauntingly expensive photographic systems.

Desperation (the father mother of invention) leads me to think a decent
system can be made 'at home' or with some straightforward machining. My
major question at the moment is how the negative and mask is held in place.
I presumed, perhaps incorrectly, that they are held without glass. Is that
correct?

Not so important notes of progress: Work on the Saltzman 8x10 enlarger
continues. Today I am finishing a filter holder, fitting the negative glass,
adding a measure/scale and other odds and ends. So far it is looking quite
good. I am still undecided on what to do about the ruined wood baseboard.
One interesting thing - most of the fasteners were torqued to lower than
expected values. All were seated squarely, but none whatsoever were tight,
nonetheless the assembly was rigid. Even the 3/4", fine thread, grade five
bolts were torqued to about 20 pounds. That is far from their capability
(wet torque spec - many were oiled before seating). Another way to put that
is that the designer used fastener girth and grade rather than torque for
rigitity, which is a good thing. Expensive, but good! So as I reassemble
with new fasteners of the same grade I am accepting the lower torque values
and will work from there.

"john" wrote

registration punches ...

If you are careful you can use a standard office paper punch.

You will need some loose registration pins. It is common
to use one round pin and one diamond pin. The diamond pin
is inserted so that its long axis is perpendicular to the
line between the registration holes. This allows some
slop when punching the holes but still maintains good
registration: the round pin defines a common rotational
point and the diamond pit defines the angle between the
sheets. If you use two round pins the system is over-constrained
and any misalignment will cause the sheets to buckle.

Nikon uses a round/diamond pin registration scheme between its
F3 camera and the MD4 motor drive.

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.darkroomautomation.com/index2.htm
n o lindan at ix dot netcom dot com

"Nicholas O. Lindan" wrote

If you are careful you can use a standard office paper punch.
You will need some loose registration pins. It is common
to use one round pin and one diamond pin.

I may be getting confused here - it is a round pin and a slotted
pin. The slotted pin has its sides ground off and normally goes
into a slotted hole punched in the sheets.

You many need to get diamond pins ground down from round
pins at a machine shop.

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.darkroomautomation.com/index2.htm
n o lindan at ix dot netcom dot com

On 6/1/2008 9:04 AM john spake thus:

Registration punches and carriers for projection (enlarging) 8x10
and also for contact printing 8x10 and larger.

All I've found so far are very large registration punches intended for
nonphotographic printing, or some dauntingly expensive photographic systems.

Desperation (the father mother of invention) leads me to think a decent
system can be made 'at home' or with some straightforward machining. My
major question at the moment is how the negative and mask is held in place.
I presumed, perhaps incorrectly, that they are held without glass. Is that
correct?

Pardon me if I misunderstand what you're trying to do, but if you simply
need to keep a negative and another piece of film (mask) in register for
an exposure, that should be pretty simple, no?

Assuming you have some way of accurately aligning negative and mask, all
a guy would want to do would be to punch two widely-spaced holes in the
"sandwich". Then the enlarger would have register pins in the
appropriate places to receive the sandwich.

I'm sure you know that the register pins used in graphic arts are still
readily available and could easily be mounted to just about anything.

Every print shop I ever worked in that used film handled it in pretty
much the same way: a simple punch (usually something homemade or
jerry-rigged) to make the holes, and register pins at exposure time,
usually taped down. Simple, effective, low-tech.

Contrary to what Nicholas said, there's no reason to use anything but
regular round pins. Two pins will keep the sheets in exact alignment no
matter what their shape, so long as the holes are sized exactly to the pins.


--
The best argument against democracy is a five-minute
conversation with the average voter.

- Attributed to Winston Churchill

On 6/2/2008 8:15 PM gr spake thus:

David Nebenzahl wrote:

Contrary to what Nicholas said, there's no reason to use anything but
regular round pins. Two pins will keep the sheets in exact alignment no
matter what their shape, so long as the holes are sized exactly to the
pins.

The reason that a round hole is paired with slotted holes (on larger
punches it is one round hole and several slotted holes) is that the
polyester film base expands and contracts in size with temperature and
humidity changes (approx 0.001" change in 10" for every 10% humidity
change). With round pins a size expansion is trapped and causes the film
to bow, preventing good contact and registration. A slotted pin allows
the film to slide in the expansion direction but prevents rotation and
maintains registration.

That makes sense, and it's true I've never worked in a shop that handled
really big film (for big presses). But in this case, the expansion
factor is probably minimal, since the O.P. is dealing with 8x10 film.


--
The best argument against democracy is a five-minute
conversation with the average voter.

- Attributed to Winston Churchill

"David Nebenzahl" wrote in message
.com...

Pardon me if I misunderstand what you're trying to do, but if you simply
need to keep a negative and another piece of film (mask) in register for
an exposure, that should be pretty simple, no?

Perfect, or as good as possible registration is the issue.

Assuming you have some way of accurately aligning negative and mask

That is exacly the problem, David. Perfect alignment with home tools to make
the carrier and punch.

I'm sure you know that the register pins used in graphic arts are still
readily available and could easily be mounted to just about anything.

All I have found are far too large, in the 30" range.

Contrary to what Nicholas said, there's no reason to use anything but
regular round pins. Two pins will keep the sheets in exact alignment no
matter what their shape, so long as the holes are sized exactly to the
pins.

I should add - this is for enlarging 8x10 negatives, not for contacting so
the degree of misalignment is magnified. Perhaps enlarging with a mask is
not the way to go.

"David Nebenzahl" wrote in message
.com...
On 6/2/2008 8:15 PM gr spake thus:

David Nebenzahl wrote:

Contrary to what Nicholas said, there's no reason to use anything but
regular round pins. Two pins will keep the sheets in exact alignment no
matter what their shape, so long as the holes are sized exactly to the
pins.

The reason that a round hole is paired with slotted holes (on larger
punches it is one round hole and several slotted holes) is that the
polyester film base expands and contracts in size with temperature and
humidity changes (approx 0.001" change in 10" for every 10% humidity
change). With round pins a size expansion is trapped and causes the film
to bow, preventing good contact and registration. A slotted pin allows
the film to slide in the expansion direction but prevents rotation and
maintains registration.

That makes sense, and it's true I've never worked in a shop that handled
really big film (for big presses). But in this case, the expansion factor
is probably minimal, since the O.P. is dealing with 8x10 film.

Someone made an 8x10 (perhaps 10x10) film holder that clipped to the edges
of the film and drew it out under mild tension. That seems to be a good idea
if it can be held by the registration pins. I guess we will just have to
make it and find out.

On 6/4/2008 5:43 AM john spake thus:

"David Nebenzahl" wrote in message
.com...

I'm sure you know that the register pins used in graphic arts are still
readily available and could easily be mounted to just about anything.

All I have found are far too large, in the 30" range.

Hmmm; maybe you don't know what I mean. The registration pins printers
(used to) use are little metal tabs, maybe an inch and a half long by an
inch or so, stainless steel, with a short (1/8" or less) pin attached.
The pin goes in the hole, and the tab gets taped down to the light
table/exposure frame/whatever. Very simple to use, and could definitely
be machined for permanent or semi-permanent attachment to your homemade rig.

Does that help any?

Hard to find pictures online; the closest I could find is this, with a
crude sketch showing a "peg bar" used for animation:
http://www.glennview.com/dkrm2.htm. Just imagine the center pin only on
a much smaller tab. (This also shows the use of rectangular slots and
pegs to allow for substrate size changes described elsewhere in this
thread.)

P.S.: While searching for pictures of pins, I ran across this page which
has a lot of stuff about Saltzman enlargers, registration carriers,
etc., in case you don't already know about it:
http://www.glennview.com/dkrm2.htm


--
The best argument against democracy is a five-minute
conversation with the average voter.

- Attributed to Winston Churchill

On 6/4/2008 10:42 AM David Nebenzahl spake thus:

Hard to find pictures online; the closest I could find is this, with a
crude sketch showing a "peg bar" used for animation:
http://www.glennview.com/dkrm2.htm.

Whoops, wrong link the http://www.saunalahti.fi/animato/pegbar/pegs.html


--
The best argument against democracy is a five-minute
conversation with the average voter.

- Attributed to Winston Churchill

"David Nebenzahl" wrote in message
.com...
On 6/4/2008 5:43 AM john spake thus:

"David Nebenzahl" wrote in message
.com...

I'm sure you know that the register pins used in graphic arts are still
readily available and could easily be mounted to just about anything.

All I have found are far too large, in the 30" range.

Hmmm; maybe you don't know what I mean. The registration pins printers
(used to) use are little metal tabs, maybe an inch and a half long by an
inch or so, stainless steel, with a short (1/8" or less) pin attached. The
pin goes in the hole, and the tab gets taped down to the light
table/exposure frame/whatever. Very simple to use, and could definitely be
machined for permanent or semi-permanent attachment to your homemade rig.

Does that help any?

Pins are no problem. It is the build of the jig and the build of the
negative carrier that matches the pin holes.

P.S.: While searching for pictures of pins, I ran across this page which
has a lot of stuff about Saltzman enlargers, registration carriers, etc.,
in case you don't already know about it:
http://www.glennview.com/dkrm2.htm

I know that prick. He doesn't answer his email. I had several thousand
dollars to spend, identified the stuff I was considering, wrote to ask if I
could make an appointment to see the stuff in person and he decided he was
too rich to sell. **** him.