Dismantling the Micro-Nikkor 55mm f/2.8 Ai-S!

[richardHaw]

http://richardhaw.com/2016/02/22/repair-micro-nikkor-55mm-f2-8-ai-s/

I hope that you enjoyed it!!!

[Øivind Tøien]

Very nice write-up and images to document it!

[Hugh_3170]

Nice write up Richard.  Thank you.

When you say "When lubricating your helicoids, be sure to use a light general purpose grease", I am assuming that you have some photographic friendly grease in mind? 

The oily aperture blade problem with the 55mm f/2.8 lens was attributed to both the wrong type of grease being used by Nikon as well as excessive quantities being used.

What grease can you, or other NG readers, recommend please?  Is there a recognised replacement grease that doesn't  lead to the same problem?

[richardHaw]

Very nice write-up and images to document it!

Thanks! it took me a long time to do this. lens is a bit complicated 

[richardHaw]

Nice write up Richard.  Thank you.

When you say "When lubricating your helicoids, be sure to use a light general purpose grease", I am assuming that you have some photographic friendly grease in mind? 

The oily aperture blade problem with the 5mm f/2.8 lens was attributed to both the wrong type of grease being used by Nikon as well as excessive quantities being used.

What grease can you, or other NG readers, recommend please?  Is there a recognised replacement grease that doesn't  lead to the same problem?

Hi! I use a light lithium type grease, generically being sold here as S10 
you can type S10 grease in ebay and this will show up. this is repacked, being sold as lens grease.

yeah, i am aware that the early production ones use a light runny grease, so grease migration became the problem and then nikon used a stiffer one. I tried using silicone grease (S30), it is a stiffer type of grease that i use for tele lenses so my turn is more precise but i ended up with a ceased lens where turning it required considerable effort. I re-greased the poor thing and this time, used the lighter S10 grease and it's all fine.

the actual grease that Nikon uses is called NPC FC-11 i think. You can read my blog post regarding grease and it was discussed there. I havent had the experience of using that but i know some people who do. also, there is this russian grease being sold on the net and they say that it is good also according to somebody i talked to. personally, I am going to stick with the tried and tested S10 grease. i usually do not apply to much of it so grease migration is at the minimum. it is not runny as well despite being light. it is more viscous than honey

[Hugh_3170]

Thank you Richard - much appreciated.

My 55mm f/2.8 is showing very slight oilyness on the aperture blades, but not enough to slow up the speed at which they operate - expoures seem to be spot on, so the blades are not causing issues yet.

I can however see the day approaching when your write up will become very valuable to me, so thank you for the effort that you have put into your instructions and images - especially given that English is probably a foreign language for you as well.  Well done.

[richardHaw]

Thank you Richard - much appreciated.

My 55mm f/2.8 is showing very slight oilyness on the aperture blades, but not enough to slow up the speed at which they operate - expoures seem to be spot on, so the blades are not causing issues yet.

I can however see the day approaching when your write up will become very valuable to me, so thank you for the effort that you have put into your instructions and images - especially given that English is probably a foreign language for you as well.  Well done.

that's fine. are you sure it's oil and not scratches on the aperture blades themselves? the scratches are OK since its just bare metal. if you do need to clean the iris assembly, you have to clean the housing as well, better yet, clean it thoroughly! you only ever need to do it once anyway  a properly overhauled lens will last for decades. that russian grease, i forgot it's name but it is supposed to be good and is used in aircraft and some other precision equipment

[Hugh_3170]

Thanks Richard - unfortunately it is definitely oil.  Only small areas at this stage and it has been slowly forming for about three years.  I am watching it and if it doesn't cause bother I will leave it as is.  However if it degenerates to a point where it is causing trouble, your tuturial will be invaluable.

[richardHaw]

Thanks Richard - unfortunately it is definitely oil.  Only small areas at this stage and it has been slowly forming for about three years.  I am watching it and if it doesn't cause bother I will leave it as is.  However if it degenerates to a point where it is causing trouble, your tuturial will be invaluable.

be careful by the way, because of the grease started evaporating, it can end up making the nearest lens element look cloudy or milky (which you can easily clean off anyway) 

[Erik Lund]

S30 grease is nice for lenses with a short focusing helicoil, like f/2.8 or 3.5 28mm 35mm 50mm lenses.

S5 is nice for really long focusing helicoils like the one here, but also other Micro Nikkor and APO Lanthar 2.5 for instance. Also non-IF lenses like 105mm 180mm 200mm,,,

S10 can be used for anything in-between and for IF lenses,,,

[Erik Lund]

Thanks for the write up.

I would love to her the explanation for this little snip at the end:

... Just remember to always store this lens facing up and set to f/5.6 or f/8 so that the aperture will not get stuck wide open or fully stopped down...


Why? 

[richardHaw]

Thanks for the write up.

I would love to her the explanation for this little snip at the end:

... Just remember to always store this lens facing up and set to f/5.6 or f/8 so that the aperture will not get stuck wide open or fully stopped down...


Why? 

ah,haha! that is an "old wive's tale" from the where i came from. i am sure that this came from a long time ago when aperture blades would rust quickly when not in use. if the rust form when the lens is at middle aperture then it is easier to just flick it off when you play with the aperture. i have seen one in the junk box wherein the aperture has rusted and the iris is wide open. the blades were fused together by the rust that formed. i believe it's a rangefinder lens that i know nothing of.

[richardHaw]

S30 grease is nice for lenses with a short focusing helicoil, like f/2.8 or 3.5 28mm 35mm 50mm lenses.

S5 is nice for really long focusing helicoils like the one here, but also other Micro Nikkor and APO Lanthar 2.5 for instance. Also non-IF lenses like 105mm 180mm 200mm,,,

S10 can be used for anything in-between and for IF lenses,,,

i actually prefer feather-light focusing on my small primes 

but yes, the 50mm f/1.2 that I bought brand new is kind of stiff, feels like the S30 was used. i personally like the S10 as it is not so thin yet not too think. i skipped the lighter one because i find it too light. they are being sold here in small tubs. which reminds me, i am running out of S10 now and i need to buy one soon 
the technicians back home use the cheaper grease for use with the shimano fishing gear. they say that it is very good and cheap! have you tried it before? these guys will cut corners whenever they can since they do not earn a lot from doing this.

[richardHaw]

http://page19.auctions.yahoo.co.jp/jp/auction/x437168743

this looks like it's priced just right 

[Erik Lund]

The Fast 50mm 1.2 has a medium long helicoil so yes: S5 - And yes a brand new, Nikon still make them, is kind of heavy in the focus feel.

I was referring to short f/2.8 3.5 lenses.

The 50mm 1.2 Ais is actually super nice to chip with a Dandelion CPU from within the mount itself since the 'light baffle' part protrudes and forms an outer metal shell exactly in the right position as a contact block.