Malcolm Stewart
Allowing Ads
I recently bought a Color Module for a Leitz Focomat V35 off Ebay. The seller described it as hardly used or some similar term, so I was disappointed when I found that the colour filters were stiff, and failed to descend after being lifted by the cams on the adjustment knobs. I dismantled the module, and gently bent the metal plates holding the filters back into shape. After reassembly, two filters worked OK, but there was still a problem with the middle filter. It followed the control cam OK, but if raised by the "Clear" rod, it stayed high. A little more adjustment cured it, so I'm happy.
This has started me thinking as to why the shiny steel* plates (~0.09mm thick) which hold the filters are so easy to bend - either out of shape or back in to shape; very little force was necessary. Many decades ago I read metallurgy, and remember a little about metals relaxing after being hardened, and I now wonder if the ~35 years since these items were made has resulted in age relaxation softening.
Any professional metallurgists here who can comment?
*Definitely steel - checked with a magnet.
This has started me thinking as to why the shiny steel* plates (~0.09mm thick) which hold the filters are so easy to bend - either out of shape or back in to shape; very little force was necessary. Many decades ago I read metallurgy, and remember a little about metals relaxing after being hardened, and I now wonder if the ~35 years since these items were made has resulted in age relaxation softening.
Any professional metallurgists here who can comment?
*Definitely steel - checked with a magnet.