Nikkor-N 24/2.8 Auto loose focus ring - fixes?

[Jim Evans]

When I played with it the other day,  the slack/slip was clearly present but I could see getting used to it pretty quickly.  It didn't seem to be something that would quit working altogether.  I think? 

It's kind of a toss up.  Do you risk further damage or problems with disassembly or do you take a shot at fixing it?   

You clearly have more repair skills than myself.   That thing would end up a paper weight If I had a go at it!   

[Scott]

No, not going to quit working.  I just have a nagging need to repair...

For what it's worth, here's a shot of the hind end of this thing, opened up:



I think the little prong/tab thingy at 5 o'clock is what moves the helical.  No slop there.

[Jim Evans]

This is way way unscientific but,  it "felt" to my fingers like the problem was in or around the actual focus ring.   It did not feel like something was loose towards the back of the lens.  When you turn the focus ring kinda hard, it feels like the "bump" when it catches is directly under the focus ring, not at the rear of the lens. 

[Scott]

Yeah, I agree, Jim.  But it's a different design from the Nikkors that you access the focus ring from the front.  A few people suggested entering from the back, but that doesn't seem to help, either.  Not sure what to do now.  I'm not stripping the aperture out of this to access anything, fer sure.

[Scott]

Okay, have gotten a bit more info on this.  Apparently, the thing I thought was the key is actually a  n actuator for the floating rear group, a relatively new design at the time.  There's a little plate held in with three screws that is s'posed to give access when removed to a split ring which adjusts slack:



Clearly, I'm missing something.  T'ain't no split ring.  I'm putting it back together now to make sure I haven't misaligned anything.  Tight spaces in there...

[robertro]

I have one of these with aperture blades that need repair. I've used it wide open - nice lens - but have that irresistable urge to explore. Any thoughts on how I would get to the aperture assembly? Front/rear?

Thanks,

[Scott]

Robertro,

If it's the same design as mine (and apparently there was more than one design in use), you can remove the front trim ring with some large rubber stopper and some pressure, remove the front lens group with a spanner, and have access to further glass and the aperture assembly.  But I absolutely didn't want to remove that.  Beyond the scope of my tinkering right now.

Scott

[robertro]

Thanks - I'll give it a go.

I'm going to try to replace the aperture assembly or blasdes if I can find replacements.