Working on the Korona

Discussion in 'Camera Building, Repairs & Modification' started by glbeas, Jan 10, 2005.

  1. glbeas

    glbeas Member

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    I spent the weekend puttering with the Korona, shimming and building a new lensboard. I worked on the focus pinions first. At some time in the past someone had managed to snap the knobs off the lefthand side of the camera leaving nubs just big enough to know something used to be there. I disassembled by removing the stop screw at the end of the bed and working the standards off the ends. Unscrewing the brackets I found a strip of spring steel tensioning the gear rod against the rack gear, rather ineffectively I might add. More about this later.
    I decided the best solution was to braze a washer onto the end of the shaft to allow a stop for the lockdown knob to pull against. Lacking a properly dimensioned washer I has to drill a disc out. First of I though a penny would do until I hit it with the brazing torch and watched it wither and fall to the bench like a dead leaf. Wierd! Forgot that pennys were now made with zinc! Poking around located some knockouts from an electrical box. Marked and drilled they brazed on pretty well with only a little popping and flaring from the zinc plating on them.
    While fitting them in I decided a little attention to the fit of the gears to the rack was due. Found out the notch the gear shaft was set in was way too deep and allowed the gear to jump over the rack teeth. Simple solution was a wood shim set on each end of both shafts between the gear and knob ends taking a little under 1/8th inch out of the depth with no binding. I put it all back together and looked it over. Messing with the geared front rise I notice it is jumping teeth too. Now I have to take the front standard off again.
    This gives easy acess to the plate that holds the gear shaft in. Removing them let me roll the board up and out of the frame. This time I find the trouble is too loose a fit between the inner and outer parts of the rising front.
    Since all I wanted was some slack removed at the gear I opted to use an iron on oak veneer strip I found at Home Depot a while back for another project. I cut a slip with the grain about 1/2 inch by 1/8th and used my tacking iron to seal them in place at the bottom of the inner part of the front. This made a fit that got rid of the slippage with no aparent binding.
    The lensboard was neccesary because the one that came with it was a Burke & James board. Same 6 inch square but the flange is much thinner than a Korona needs. The Korona dimensions need a 1/4 inch thick flange cut slightly more than 1/4 inch in on my 3/8th thick board or you might just use a simple 1/4 inch board. I think the thicker board gives a better light trap.
    Hopefully this will make the camera easier to use with some of the rattles eliminated.
     
  2. blaze-on

    blaze-on Member

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    Korona man

    Gary, I restored my 4x5 Korona this past year and had a similar problem with shaft and lock down washer at opposite end of knob. I believe they did not have a knob on the front left side, just a washer that "floated" and was retained by a peened end. I have looked at several and none had a knob, just washer-so you done good. There should be a slightly smaller dimension to the steel shaft at that end. Mine (washer) was missing, but I used a #10 or 8 zinc and had it brazed on by a machinist friend. Tends to creep just a tad when locking down but no biggie, as I rack out the front just past infinity focus then fine tune with rear. I did the same with rear shaft and also moved the gears over a tad on shaft as they had moved some over the years and made indents on the wood. So heated 'em up to loosen, positioned on track and resoldered. Then buffed it all out on the grinder with
    polishing wheel.

    The spring steel under the front standard is a bit weak, but I bought another 4x5 for parts and to use the front ext. as a rear on mine (empathy please).
    I think a shim under these might work well too. I had basically taken the entire camera apart, ext. frames and all and reglued in a squaring jig with gorilla glue.

    All in all a pretty stable camera. My only wish is that it would lock down tighter on the front shifts/swing block. But I'm working on that.

    I bought the 8x10 version (it's momma) with all the front tilts and swings (like the 4x5) and will be getting to that soon.

    For some reson I really like the Korona, maybe cause it's my first LF or it's uniqueness.

    I have a rear standard from an EK 2D that I pieced the rest out on UPAY and am thinking I can incorporate the geared rear swing from this into the Korona rear. We'll see.

    I used two pieces of 1/4" hobby ply for the lensboard and worked well. That way you can drill the outer circle and inner separately before gluing.
    I'd like to see a pic of yours, and is yours an 8x10 or ULF?

    Regards
     
  3. esearing

    esearing Subscriber

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    You guys are tallented. I found just installing a calumet replacement knob to be difficult, not to mention losing tiny screws into the carpet.

    Hey Gary, Think you could whip me up a couple of lensboards for the Anba?
     
  4. matt miller

    matt miller Subscriber

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    Thanks for sharing this Gary. My Korona's front standard tends to jump & slip sometimes too. I'll give this fix a try.
     
  5. glbeas

    glbeas Member

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    I might have one laying around I made from a metal plate. Really best to get a Wista/Techinka style board. I've found several for pretty good prices on Ebay. One you will definately want is a recessed board for when you get a 65mm lens to play with. My 90mm can be used with a flat board on the Anba.

    BTW, never mess with tiny screws over carpet, unless its a short pile chunk laid facedown on the work table. The smaller the screw the further it seems to bounce from where you thought it landed, Murphy at his best!
     
  6. glbeas

    glbeas Member

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    Does the 4x5 have the pointed prong that seats in a hole in the back to hold the rear stop down for extension focusing?
    Mines an 8x10. I don't have any shots of it but theres a few in the Who shoots LF thread thats pretty near identical.
     
  7. blaze-on

    blaze-on Member

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    Gary, not sure what you mean...the small metal tab that sits in the main base (vertically) with a spring to keep the rear standard from going backwards off the track?

    If so, yes, but I replaced the spring.
    If not, explain again.
     
  8. glbeas

    glbeas Member

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    Yes, I mean that spring loaded tab. On my 8x10 there is a hole in the bed that a pin on the extension goes into that will lock the tab down. You have to push the tab down when mounting the extension to allow the pin in. If you are using spare parts without this pin and your camera is so equipped with this lockdown feature you could easily fabricate a pin and screw it into your extension in the right place. If need be I can post some digishots of the parts in question so you can see what I'm talking about.
     
  9. blaze-on

    blaze-on Member

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    spring pin

    Mine has it Gary..so does the 8x10 along with the rear extension to get
    32" or more...can't wait! Need lenses, film holders...
     
  10. glbeas

    glbeas Member

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    Okay heres some shots. First is the camera, second is an illustration of the differences between the Korona lensboard and the B&J lensboard, third is the brazed on washer on the focus shaft and if you look close you can see the shim wood behind the shaft.
     

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  11. blaze-on

    blaze-on Member

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    You know, I should have fabricated my own washer to give me something bigger like yours. But it does what it's supposed to. The good thing is the springs on the second (parts) camera I have are stronger and should help on the 4x5.

    I'm working on a method to add a geared lensboard tilt mechanism. something that you can adjust more delicately. I'm first going to construct a "dummy" set-up to try first. If it works I'll pm you the design.
    Similar to what the agfa's have but adaptable (I think) to the Korona without
    taking the front standard assembly apart and simple hardware parts. All supposition at this point.

    I like bringing something back to life (so to speak), to continue it's use, wondering who has owned it over the years, what photographs they taken, where it's been.
     
  12. Mongo

    Mongo Member

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    Pardon me for jumping into this thread, but I had to share my joy...I (finally!) finished my re-build of my Korona Pictorial View tonight. I'll be making lensboards tomorrow and shooting with it over the weekend (as long as the weather cooperates).

    This camera is destined to become my 8x10 enlarger, but it's been a blast restoring it and I'm looking forward to shooting with it a bit before I start up the enlarger project. It's not quite original as I got a good deal on some bellows that didn't quite match the original in size so I had to build an adaptor for the front standard, but with a lensboard in place noone will ever know.

    I'm amazed at how solid a camera of this age can be with a little TLC.