Hexanon 35/2, oil in blades

[Zamo]

I recently got a very good looking Konica Hexanon 35mm f2 (together with almost new Autoreflex T3, 200/3.5, 50/1.7 and 100/2.8. The owner had a nice set, and barely used it), with the famous (for this particular lens) oily blades. Not too bad, they still move, but could use a cleaning. I am not sure yet, I have to try it more to decide if I should do it or not. I am no going to disassemble the blades, etc, too complicated, but I have had quite some success with other lenses by just cleaning some of the oil in the blades by opening and closing them and carefully removing the oil with some isopropyl alcohol. Not sure if I should try to access them from the back or from the front side. Any experience or ideas about that? Thanks in advance!

[stevemark]

Others certainly have much more experience when it comes to repairing Konica Hexanons, but I found them to be a little complicated, especially when comparing their construction to the Rokkors I know better. On the other hand I never was afarid of taking the aperture mechanisms apart. For me usually the difficult part is removing the nameplates (if necessary), and to unlock some blocked screws. And of course the usual caveat regarding the tiny steel balls in the aperture mechanism apllies also to Hexanons. They are ejected pretty nicely unless you really prevent them from doing that!

Cleaning and re-assembling an aperture mechanism (blades!) is straighforward if you know how to do it. I have given an exact instruction for the Minolta MC 1.7/85mm here (scroll down to "Reassembling the aperture mechanism"):

http://forum.mflenses.com/viewtopic,p,1546112.html

It will work similarly with other lenses.

S

[Zamo]

Thanks, Stephan. I still have to decide if I should open it or not. Still, I do not feel I should dismantle the blades, too complicated (although, step by step and documenting everything profusely I think I could be able to do it) and the lens too valuable. I would try to do that with a couple of "fungused" Domiplans I have, but not with this one...

[stevemark]

[BrianSVP]

re: lost ball bearings, the key with disassembling a lot of these HExanon lenses is to know that they often use a unique setup for the click detents. To disassemble without losing the balls, look for the two set screws in the aperture ring visible when looking down from the back. These each compress a coil spring, underneath which is the ball bearing. One side has the detents for full stops, and the other, half stops. Once you remove these set screws, the compression is relaxed on the springs, so the balls won't go flying. The set screws can also be used to adjust the firmness of the clicks if you prefer a tighter or looser feel.

Later Hexanons (usually the ones with plastic aperture rings)tend to use a more typical leaf-spring/single ball arrangement, which doesn't have a tendency to shoot the ball bearing off on disassembly.

Not 100% sure with this model off the top of my head, but to disassemble from the front on many of the Hexanons of the same generation, you have to remove the name ring, then there is a set screw that secures the barrel that has to be loosened, then the entire barrel screws off from the front, which will typically allow you to pop out the entire optical block (there may be a second retaining ring that has to be removed), allowing the lens cells to be removed much more easily. If that's the case, then you won't even have to take the rear mount off, and you can avoid dealing with the aperture ring entirely, not to mention resetting focus, etc.