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Mick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 29, 2005 - 01:33 pm: | 
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An unfortunate buy from E-Bay, I have a lens that has a dirty diaphram and an unknown focus. Has anyone got details of the breakdown of the lens so as to clean the blades and reset the lens elements? I suspect that repair has been tried before as one side of aperture blades are clean, otherside dirty. Are the front elements held in a common helicoil ? Help please !!! |
rick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 29, 2005 - 04:24 pm: |
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This may depend on what camera the lens was made for, and when. I have a sketch for the LTM version, and I think the M39 Zenit SLR version is very similar. I don't know if this would still be good for a later M42 version of the lens.
But you're welcome to have a look at it.
rick : ) = |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 29, 2005 - 06:05 pm: |
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The Kiev Survival Site has detailed instructions on how to refurbish the helical/mount.You do not say what mount you have,but as I have used Kiev info to strip M39 Jupiters (not a 9 though)I think the following may be of help.The pictures of a Jupiter 11 optics strip on the above site also gives good pointers
It appears that as on other Jupiters, the optics screw out from the front as a complete assembly.Using thin rubber sheet grip the front of the lens and unscrew anticlockwise.Do not loose the alloy shim washer that will be just sitting on the male threads.If no washer then lens has been got at and you have a problem in setting up focus.
Now the bright alloy aperture ring is normally held by 3 small grubscrews.Loosen and unscrew it.If lens has been bodged,then Loctite may have been used if no grubscrews.
Now look for any grubscrews that lock the front ring (filter mount) to the lens block and loosen, normally only one screw is used here.Then unscrew the front ring (anti clockwise)and remove front element/elements.Not sure on the 9's optical construction.If you cannot unscrew the front sub assembly, see if the name ring has two slots for a lens ring spanner.If so remove and lift out front element,spacer and then inner element.Rear elements will come out as a screw on sub assembly or as separate elements,held by screwed rings.Looking at the pics on the above site just try unscrewing the complete rear ring first,before removing retaining rings.
At this stage flush clean the iris/lens block sub assembly with Naptha or lighter fuel.
On the male threads of the lens block you should see a screwed ring that retains the iris control 'funnel'. This ring is locked by a single grubscrew,loosen and remove the ring.The 'funnel' is now retained by 2 screwed pins in the actual iris ring.Remove these and unscrew the'funnel'.Replace the screwed pins carefully.The pins retain the ring that holds the iris blades in place and if you still have old grease to remove, it is better safe than sorry.
On reassembly place a small amount of grease on the inside of the 'funnel' and screw back on.Do not screw tight-it has to work the iris ring through the slots.Clean optics and complete assembly of lens block.
On the mount assembly, if Kiev follow the diagrams on the above site.If M39 you just keep loosening grubscrews and removing the focus ring and datum scale.You can then strip the helical.Set the focus against the infinity stop and note position of stop screws etc.Scribe reference lines,note when helix parts and where,in reference to each other.
I use a silicon grease.Maplins sell a good product,but the one I use is sold by all UK plumbers merchants to lubricate rubber O rings in soil pipes and potable water systems.Definitely no creep and just the right damping properties.
The above is based on refurbishing many Jupiter lenses,however as stated I have not worked on a 9 and have just been comparing notes and pictures.Still Jupiter 8,11 and 12's are so similar to each other and the 9 does not look much different.
As for focus,is it just the distance ring misaligned or is that damn shim missing?Another problem is that a lot of mix,but no match occurs with some e-bay dealers.Even if the shim is present,it may not be the correct one.Still reshimming is relatively easy. |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 30, 2005 - 12:37 am: |
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The J9 is very difficult to disassemble since it uses two helicoids, one for focussing and one for moving the rangefinder coupling (in LTM mount). Only thing you can adjust is the inf. focus by adding shims between the optical block and its mount.
If focus and/or rangefinder coupling is totally off, either someone has swapped parts from another item or reassembled them the wrong way. It is not possible to swap parts of the helicoid(s) from one item to another since they are 'factory adjusted' (i.e. holes for coupling pins are drilled in proper position). |
Mick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 01, 2005 - 02:43 am: |
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Sorry, I should have said, lens is m42 mount and has no rangefinder coupling, its black, brass underneath possibly because of weight, has uncoated optics, and has preset diaphram.
Upon closer inspection, one grubscrew seems to have been visited by a screwdriver, it is the one on the external barrel only visible when lens is fully extended (ie. focussed out).
Thanks for the replies, am copying to paper, so that I can read as I attempt to dismantle the lens.
Incidently, the lens has no external physical simularity to the jupiter 8 lens I have.
Thanks again....... will say how I got on later. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 01, 2005 - 10:25 am: |
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A scan through Princelle's 'Made In USSR' indicates that the external shape of the 9 varied quite a bit from one maker to the next.This is especially true when you look at the early M42 models.
I think you will find the the single grubscrew on the barrel is the one that locks the optic block into the mount proper.
For interest who is the manufacturer of your lens at what is the serial? It appears to be early |
Mick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 02, 2005 - 06:31 am: |
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Thanks to Glenn,Winfried and Rick.
Have succeeded, Inside elements were well coated with grease, and after cleaning, and washing out with lighter fluid,lens shows good definition on focussing screen on camera though not tested with film yet.
Breakdown is as follows:
Remove Aperture control ring (3 grubscrews to loosen)
Remove Preset control ring (3 grubscrews to loosen)
Loosen top lens block grubscrew now showing near top of lens (although you may need to remove top element from this block first - lens spanner on filter ring insert).
Twist off front lens block and yes there is a copper spacer immediately underneath.
Rear lens block falls out after removing the rear ring with a lens spanner. At this point I was able to clean the iris and glass.
I think the grease had leeched from the helicoil, it was very apparent on the inner surface of the front lens block.
Thanks everyone
Mick |
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