Wollensak 3.5" (90mm) F 4.5 ENLARGING PRO RAPTAR, anyone know the thread size?

Discussion in 'Darkroom Equipment' started by jjphoto, Mar 4, 2013.

  1. jjphoto

    jjphoto Member

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    Does anyone know the thread size of the jam nut for a Wollensak 3.5" (90mm) F 4.5 ENLARGING PRO RAPTAR, or can anyone point me in the direction where I could find out?

    TIA.

    JJ
     
    Last edited by a moderator: Mar 4, 2013
  2. Newt_on_Swings

    Newt_on_Swings Member

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    I'm looking into this lens as well and I think it is a 25mm thread. You can take a ruler to it and measure it too.
     
  3. jjphoto

    jjphoto Member

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    No. It's no where near 25mm. It's closer to 40-41mm, it fits inside an M42 thread. It also has a relatively coarse thread similar to a 26tpi (looks like an M39x26tpi or M39x1 thread spacing).

    No doubt it's an odd imperial thread, but that's just a guess anyway.
     
  4. Newt_on_Swings

    Newt_on_Swings Member

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    Oh hmm, that is odd. I was hoping to use such a lens on my enlarger setup. I hope someone here knows for sure.
     
  5. Ian C

    Ian C Member

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    The Rochester, NY made lenses regardless of brand usually used standard fractional inch diameters. The diameters vary depending on the physical size of the lens. The threads are usually 30 threads per inch 60° Unified thread.

    For example, my 162/4.5 Wollensak Enlarging Raptar uses 2.0” diameter x 30 threads per inch 60° Unified thread.

    I also have a flange that is 1 3/8” diameter by 30 threads-per-inch (lens unknown, but almost certainly one made in Rochester, NY) that was installed on an Omega DII/D2 lens plate.

    If the threaded shank of your lens is 1 5/8” diameter, that would be about 41mm major diameter. So a reasonable guess might be 1 5/8” diameter. If you can find a mechanic with a micrometer or dial caliper, the thread diameter can be measured accurately. He or she would need an inch-designed set of thread pitch gages to determine the thread pitch accurately.
     
  6. jjphoto

    jjphoto Member

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    Thanks for the info.

    JJ
     
  7. Newt_on_Swings

    Newt_on_Swings Member

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    I guess that's understandable, thank you for that bit of history. I searched For awhile as well and could not find a thread size for the lens, the closest I got was one eBay auction where it was measured at the widest part of the lens, 1.625 inches, roughly 41 and some odd mm. Doesn't really help much at all sadly.

    I hope you have luck with finding an adapter for it. I'll keep on looking for another 6x9 lens.
     
  8. jjphoto

    jjphoto Member

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    I haven't actually tried/tested the lens yet, I've only had it a few days, so I don't know if it's worth going to any effort to find or make a retaining ring for it. It's not hard to temporarily adapt the lens to a digital body for a test, and that's what I'll do before going any further with it.
     
  9. Paul Howell

    Paul Howell Member

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    I have WS 50mm, 90mm 135mm and 162mm, all are very good stopped down to F 8 or 11. Saying that I would not spend much time trying to find an adpator as there are many 90-105 enlarger lens with standard threads. I have an D3 and in the past have cut out thin sheets of plyboad drilled holes of the set screws and lens for lens board, painted flat black, then found a locking nut at the hardware store to hold the lens. As long as the wood does not warp will work.