Tessar 50mm alu reassembly

[Jesito]

Thanks so much for all these clear and understandable instructions.
Some time ago I got a 50mm 2.8 Tessar Exakta mount from Carsten, as a part of a Exakta deal. It was unassembled.

Since then it has been my favourite puzzle.

Unfortunately I've been unable to set it up again. The parts of my Tessar seem to be slightly different:





What do you think about it?.

I'd be really happy if I could make it work again.

Thanks in advance.

Jes.

[Arkku]

[Jesito]

Thanks a lot!.
I'll try it and take pictures during the process...

Regards.
Jes.

[peterqd]

Did you leave your green filter on Jes?

Good luck with the lens.

[Jesito]

Let's go step by step:

Let's call those three separate parts in the picture from left to right 1, 2 and 3.




It seems to me that the reassembly procedure would be:

• Remove the largest of the rings around the rear element (in part 3); it should simply screw off.



• Put part 2 on part 3 (there should be some peg or such to indicate the correct position where it cannot rotate).






• Remove the focus limiter from part 1 (it should be a large screw on the outside).

I see no outside screws. Inside there are two holes, one of them holds a screw that once removed allows for turning the base:






• Turn the focusing ring clockwise as deep as it will go (it will eventually get stuck; don't try to force it to continue!).



• Then turn it back so that you pass infinity focus once, and keep turning back the focus mark is at the minimum focus distance.



• Put the parts 2 & 3 (combined earlier) on the table with the front element down. Now aim part 1 so that when you look through the mount hole, the peg inside part 1 is a just a bit clockwise of the slot in part 3 (the focusing helicoid) into which it must go. Hold on to the focusing ring to maintain the focus position we set earlier and turn the entire part 1 counter-clockwise to get it onto a thread in part 2 (the focusing helicoid). This may take a couple of attempts; if it goes too far counter-clockwise, try again from a more clockwise position—the idea is that the peg should be clockwise of the slot when the threads engage. Once you get it right, you should be able to exactly align the peg with target slot by only a very slight turn of the entire part 1 (don't allow the focus ring to move separately!).

That's where I'm stuck now. I get to put the peg just clockwise but no progress from here is possible, it gets somewhat locked. To make the peg fit the thread I have to move only the focusing ring, not the whole ensemble...



Well, too tired today. I'll keep trying tomorrow.

Thanks again,

Regards.
Jes.

[Jesito]

[Arkku]

[euphilein]

Well, thanks to all of you guys!
With some help of the postings here, i was able to reassemble my All Tessar.

After some tries i was able to reassemble the 3 big parts within seconds.
Then i needed some more tries to adjust the focus on infinity.

Some hints:
- Screw the focus ring into the mount ring
- Screw back passing the infinity mark just one time
- Continue with screwing back and align the focus mark on infinity (not passing it second time)
- Follow the instructions in this thread to assemble the focus ring+mount ring with the remaining third part of the lens, aligning the peg with the help of the mount ring
- When you got it, turn the focus ring towards infinity, the focus will be correct if the focus mark stops just a bit beyond infinity mark
- Screw in the focus limiter while having the focus mark somewhere between infinity and shortest focusing distance

Maybe this helps

[user]

Thank you very much to the helpful people here. With your help I managed to put my Contax F M42 version of the Tessar back together perfectly.

At first it seemed more difficult than Rubick's cube, but with these instructions and some practice I can confirm that it's actually just a matter of seconds once you get the hang of it.

So don't get discouraged if you don't manage to solve the puzzle instantly. It will take some trial and error, but with some patience you will eventually get there.


Here are a few additional hints:

After screwing the focus ring all the way into the mount ring, screw back almost one full turn - past the minimum focusing, but not past the feet/m or infinity mark the second time - about 1cm right to the feet/m worked best for me. Yours may be slightly different, so you will need to choose a different starting point if your infinity focus is off.

I set a small aperture like f/16 before assembly to get the aperture lever out of the way. I then aligned the big latch to the big hole in the other part.

When putting all the pieces together I wrapped my right hand around it and used the index and ring finger to fix the upper and lower part while turning the focus ring in the middle with your left hand. Some nodding is necessary to get a perfect fit.

Good luck!

[Volunteer]

When A is put on C and B screwed on A+C, how does that hold in place as C isn't screwed on A?
I suddenly can't screw B1 and B1 together all the way. It was working well till an hour ago and now it just stops at one point and is very hard to turn. Should I lubricate it?

[NikonD]

one question: is that screw also responsible for holding the lens together or is it just to prevent to go "beyond" focusing
I have one of these tessars and successfully reassembled it but it keeps falling apart, and the screw is missing...

[tromboads]

Hasan and Jieffe

A Big Thank You!!!!

literally just registered here so I could shout your praises to the high heavens! My little tasser is all happy chappy together again!


Just for the record, I re-lubed it with "Tri-Flow" yes, its a bicycle chain lube... It didn't work. The grease needs to be thinker. Everyone else has been warned

[tromboads]

[uddhava]

Thank you Hassan and others who contributed to this post I was able to lubricate and reassemble my Tessar
with your help.

[Cheffalo]

I tried this maneuver today, with my lens exactly the same as yours above here. Finally I managed to re-assemble it but the part C keeps falling off, it isn't attached to anything. I don't have a clue to how to fix this and I'd appreciate some input here!
Thank you!

[hasan]

[Cheffalo]