Well, I'll have to make it... it has has to fit in the Nega 138 ...Originally Posted by Drew Wiley
Well, I'll have to make it... it has has to fit in the Nega 138 ...
Pere Casals if you ever able to make the nega 138 work for mask registration let us know how you did it !!!
Durst did it themselves - GRAHAL & GRANE are the parts. The problem is finding the punch that matches them. They replace the NEGA 138 in its entirety. Essentially GRAHAL is a precision metal block that locks to the chassis & the GRANE registered carrier then slides precisely & repeatedly into that. If you have access to precision machining, they are not hugely complex parts to make a version of.
I've designed a version for 4x5 only in the Nega 138 that requires only two precision drills on a metal plating, the rest, glass included will be cut with a waterjet:
(It looks like if the plating is blocking the image but's only an effect from perspective)
It uses 1.5mm pins and the sheet is punched in the 5" side, for a 20% better alignment.
The top glass is ANR 4mm, its weight is to keep the thing flat. I'll DIY the ANR glass: https://www.largeformatphotography.i...=1#post1521082
If somebody wants the drawings please PM. This is the Landscape version, the Portrait version varies in the base glass drills. The DWG file for the cuts can of course be edited tu suit any pin diameter and distance.
So by just replacing the base glass in the NEGA 138 we have a 4x5 registered carrier, with al confort/convenience a Neg 138 sports, I love the Nega 138
I'm thinking in a 5x7 carrier that would require some modifications in the NEGA 138 frame, as the base glass is just 13x18cm, modifications would be small, but before "damaging" a NEGA 138 I want to think it well.
Last edited by Pere Casals; 26-Oct-2019 at 05:16. Reason: spelling
I have a GRAHAL/GRANE which I modified to match my 4X5/5X7 Condit punch system, but have never used it yet because I've been concentrating on 8X10 images; and I have separate registration equip for that size. But there's no need for registered carriers in basic masked color printing where the final mask is taped in register to the original, but only when you need sequential exposures in register, like for color separation use.
Having used 138s on a day to day basis for years, you're missing a fundamental issue: the NEGA 138 isn't designed for registration to the enlarger chassis & if you can't solve that problem, any pin register system will be extremely limited in its usability. The GRAHAL locks to the chassis and the GRANE registers to pins in the GRAHAL. You will have an easier time designing a base unit that locks to the enlarger and a carrier that registers to that than trying to modify a NEGA 138.
I still don't think water cutting is a good idea anywhere near optical surfaces - the cutting material is much the same stuff used to grind lenses.
Agreed. The Nega 138 is perfectly suitable for enlarging a neg or chrome with a mask already taped in register to it. But it is worthless for attempting to make sequential exposures in register with one another, and would be an exercise in futility to attempt to modify for that purpose. I have at times made my own registration carriers, but starting from scratch. Any decent machinist could do it if an appropriate design was communicated to them. The tolerances have to very tight, yet still allow precise positioning with thermal exp/contraction issues already factored in. Condit made their own registered carriers for various popular enlargers. Matched Durst components are now hard to find; and their own punches are nearly nonexistent. I saw one of the later deluxe 138 register carriers for sale on EBay earlier this year, the model which replaced the GRAHAL/GRANE system. Somebody eventually bought it; but they must have had a rude surprise when they discovered they needed a matching perimeter component to make it actually work, and it wasn't included - probably long lost.
interneg, let me reiterate, you place a protective/adhesive plastic film on the glass surfaces, that film won't even be damaged but, is the film is not perforated you know that now corindon particle reached the glass.
In fact risk of scratches is at the bottom, from the steel blades supporting your material:
https://my.wardjet.com/waterjet-support-systems
So a protective material should be also placed under, say a thin cellular plastic sheet. I use it to cut (often polished/satinated) AISI 304.
So, once again the truth emerges: you've never had glass cut with a water jet. I've just spoken with a local specialist glass supplier who water cut all sorts of glass for engineering & technical purposes & their comment was that they were unwilling to cut a smaller than 6mm hole. Which is not much use for either a 3.5mm hole for the pin body or clearing the 1.5mm pin itself in the top glass.
Interneg, now Im a bit busy, later I'll explain you about that....
For the moment use google a bit to get informed
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