Pin registration system preferences

[interneg]

For those who use pin register systems, do you find the small pins within the film margins (Condit, Inglis) better/ more precise than bigger pins on a taped on strip (Radeka, Durst)? I'm in the process of assembling a carrier for my 8x10 enlarger (a De Vere 5108) & wanted to get a sense of what people feel works better for more heavy duty sequential work. My own sense is that the fine pins tend to be more precise overall, but the bigger pins tend to be easier to enact on equipment in terms of adaption/ assembly - in the main this will be for printing colour neg using RGB filters as well as working with separations for various processes.

[Drew Wiley]

I have a complete Condit micro-pin system, including registration punches, contact frames and glasses, etc. I've personally adapted glass for my Durst and own 8x10 registration carriers to match this. Registered CARRIERS are NOT necessary for basic masked printing, only for things like sequential color separation negatives like you're interested in. Offset-diameter micro-pins might now be impossible to find; but similar diameter stainless pins can be acquired from McMaster. Drilling the glass and correctly aligning these pins is tricky, but a doable procedure which can be described if necessary. I am unfamiliar with the DeVere system, so can't help you there with respect to carrier modifications.

[interneg]

I'm making a light source & carrier that more closely matches my needs - I have various dislikes about the later De Vere carrier (especially the hinges) & its pin register variant is a bit improvised in my view. The main headache is how easy it is to drill suitable holes in a coated glass like Schott Mirogard - at a guess something along the lines ofa lapidary drill bit will be needed to safely drill the glass.

Regarding the eccentric pin, I take it that it was designed to describe an arc as it rotated to allow for ultra precise matching to the punch? There are a number of approaches I can see that would achieve the same result - I notice the Inglis carrier achieved the same end by using a small plate holding the fine pin & a bigger pin attached to the holder - it describes the same arc. Making a suitable pin with the offset would be downright easy for the toolmaker I'm going to work with on this project, so I'm not particularly concerned about it.

One other question for Greg: would you happen to have the 5108 manual? There's a very specific question I have about the neg stage to column spacer on the DVB/ DVW model - if you don't, don't worry - I'll bother John Boyce of Odyssey about it sometime this week.

[Eric Woodbury]

I'm no specialist on this topic, but if you want a quality 1/4" punch, it is generally available from ebay. It's an ACCO Products 2-hole punch from the 30s on through 50s. A nice sharp solid pin. Cuts a good hole. Made in USA.

[Peter De Smidt]

I have one of the older 504 pin-registered carriers, the ones without the plastic hinges. I use it on my newer 504, even though the carrier is thicker than the new one. To do so, I made 1/4" metal spacers to replace the ones in the head. They simply have to be a bit longer to allow the thicker carrier to be insert. De Vere uses Kodak-style pins. A while ago I was able to buy some from Stossur. I probably have some spares.... To be honest, though, I didn't get much in to masking, and so I use on older non-pin-registered carrier in my 504.

[Drew Wiley]

Eric - that's not the kind of punch in mind. Even if it was 1/4", that diameter would have to be absolutely precise, and the spacing between the two punch holes has to be reliably consistent within a few thousandths of an inch every single time. Something like that is readily available from Ternes Burton or Olec Stoesser. But unless you're just punching a taped-on strip of film, a 1/4" hole takes an unacceptably drastic amount of meat out of the edge of a negative.

[Drew Wiley]

Interneg - drilling thin coated glass is risky to say the least. There are miniature solid carbide bits from McMaster-Carr that might do it on a precision drill press without almost zero chuck wobble. The special type of glass Condit used for drilling has not been available for a long time. What I've done instead is to split a thin brass register strip into two halves with a missing bit of space in the middle. Then I've every carefully ground a precision shallow groove in the glass with an on-edge small rubberized abrasive Dremel wheel (McMaster). Then the two opposite halves of the pin strip are set into the groove with wet 2-ton thin epoxy while firmly attached to a prepunched piece of film. Keep the epoxy off the top of the strip or film itself. Weigh or tape everything down perfectly flat for at least 24 hrs. Clean up any epoxy overage with acetone. This is a simple procedure in concept, but more like being a surgeon in its finickiness. But it sure beats chipping or shattering the glass with a drill bit.

[Pere Casals]

Interneg - drilling thin coated glass is risky to say the least.

Today this is easy:

https://www.youtube.com/watch?v=E1QaQHjCAv4
https://www.youtube.com/watch?v=1TEhYy4AcfM

CNC waterjet made holes may be a bit conic, so a polishing may be required later.

[interneg]

Today this is easy:

https://www.youtube.com/watch?v=E1QaQHjCAv4
https://www.youtube.com/watch?v=1TEhYy4AcfM

CNC waterjet made holes may be a bit conic, so a polishing may be required later.

It's an abrasive jet, the spray is not good for coated optical surfaces. I looked at laser cutting but I think it would be prohibitively expensive. I'm not entirely sure what was special about the glass that Condit used.

[Pere Casals]

It's an abrasive jet, the spray is not good for coated optical surfaces.

The glass surface is protected with any adhesive plastic layer, no problem. The CNC is very precise, and holes and dimensions are well in place, single thing is that the cut is not exactly perpendicular to the surface because of effects in the jet, some advanced machines inclinate a bit the jet to perfectly compensate that angle while the head is moving in any direction.

Waterjets have an operation cost of (perhaps) around $200 per hour, but that job would be cut in less than one minute, so most of what would be invoiced is machine preparation cost and bureaucracy.