Jupiter-12 LTM CLA ? --daily stupidity--

darkkavenger

Massimiliano Mortillaro
Local time
11:08 PM
Joined
Jun 9, 2005
Messages
1,910
Hello,

I'm in France and tried yesterday with my dad to fix the focus stiffness on his LTM Jupiter-12. Disassembly went fine, however, now that we try to reassemble, the inner conical element (f-stop ring) screws itself inside the barrel but seems to go too down, making it impossible for the fstop ring to turn properly. I've seen a DIY guide but it was for a bayonet J-12.

Any help is most welcome, at this point I'm feeling =really= dumb and I'm even considering to send the lens for service.

Many regards!
Max
 
Check two things:

1. you placed the focus shims back in place

2. try backing the aperture selector out one full turn, and replace the screw

If you are still stuck, PM me.
 
Thank you both and allright, I'll try these things. I will also try to take some photos of the disassembled Jupiter-12 once we get back home. Now we'll go out to take some photos near Menton and Ventimiglia (in Italy), we'll take our RFs (my dad: Zorki6 and I50, me: Kiev-2A and 50/2 Sonnar) and we'll leave the Pentacons at home :)

I think I better stop being curious and disassemble things! Nicolas, I wouldn't certainly be able to restore a Contax like you do :)

Thank you again,
Max
 
I'm finally back home in Prague after visiting my parents. I'll have a more thorough look at the J-12... I've also a Kiev-J12 to reassemble (will be easy) and an I61 L/D to grease. :)
 
The adventurer dangerous proceeding

The adventurer dangerous proceeding

The anti-K(i)SS cook adventurer dangerous proceeding I learned by accident while black painting my chromed Kiev lenses.

Not for Max as he already dissasembled his lens, but for those with their lens still assembled:

- Put your stiff lens within your home big cooking oven (not the small grill, nor microwaves) at a temperature of 50 centigrades.
- NEVER PLACE YOUR LENS CLOSE TO ANY OF THE 6 SIDES OF THE OVEN, BUT RIGHT CENTER AND AT THE MIDDLE HEIGHT, unless you want to eat it for breakfast.
- Leave the lens there for an hour.
- Close the oven switch to "off", open the oven and let the lens cool a bit for some three minutes, just in order to be able to touch it.
- At this point the lens will be quite hot, and the old grease quite melted, so the lens may move quite good.
- But here begins the problem: when the lens will cool to room temperature, the melted old grease will slowly re-stiff again. Therefore use the time the lens is hot to rotate back and again whatever part you wanted to loosen.

If this doesn't help, start reading again the K(i)SS (Kiev Survival Site).

And don't forget to use the oven temperature to warm a sandwich or something.
Cheers,
Ruben
 
Last edited by a moderator:
So I returned to my little home in Prague last tuesday after a short but enjoyable and relaxing weekend spent in France at my family, I'm back in great shape, I suffered lot of stress and even panic attacks the last two weeks - stress from work and probably an afterwards emotional shock after my dad's heart attack that happened at the end of october --he's been treated very successfully then and has lost about 15 kgs already, he's in the best possible shape--.

So... my dad J12 was focusing well after remounting it but was stiff when mounting on his Zorki-6. I tried it today on my Fed-5 and it is smooth like silk and accurate. I'll run a roll of film through the Fed-5 + J12 combination (HP5+) and I'll keep you all updated :)

Cheers,
Max
 
Hi Max,
Glad that your Dad is 'on the mend' as we say here in the UK.

I have a J12 which sits nicely on a Mir,and focusses smoothly,but the same lens is difficult to screw onto my Fed 2,and focusses quite stiffly.I think that the extension on the rear of the lens is binding , or rubbing ,slightly against the rangefinder arm of the Fed 2.The Fed focusses smoothly with my 50 mm.lenses but is not happy at all with the J12.

I think that I have read somehere that the r/f arm can be adjusted upwards with a pliers,(but to be honest I am afraid to do so in case I cause some damage and possibly upset the way the camera focusses with 50 mm lenses.) Perhaps this may be similar to your current problem.

Brian.
 
Back
Top Bottom