Zeiss Ikon Tenax I dismantle (help!)

[truls]

I will try to dismantle the tenax to clean the lens. This is somewhat a new experience, so if someone have any propositions now I can get further. The work stopped due to no more tiny screws to unscrew... Here are some pictures:


I did remove the four screws, and removed 3 small covers.


Here is the inside of the back after removing the four screws and covers.


Then I removed four tiny (really tiny) screws from the focus ring. The lens becomes somewhat loose but it wil not come off. Here are the disassembled parts.

Well, what to do now? Should I put some force to get off the lens?

[Stephen]

It looks like I have a different variant internally, so best put back the screws inside. It looks like the shutter back is not going to just give access to the lens, the back glass can be cleaned on the B position, I suspect the front is the only access to further internal elements.
There may be very small screws in the rim of the aperture ring, or the lens name rim has indents that will allow a two pin spanner to remove it, it should be screwed in to retain the front element direct, or via a secondary screwed brass collar on the same screwed thread, visible after the name ring is off.

[Stephen]

The exposed screw which rests against the focus stop on the lens front, should remove, and the outer part of the front ring un-screw off, this exposes the aperture ring edge where there are further screws to release the lens elements from the threads.

I will try to contact a friend who is more expert in Zeiss. The usual arrangement is that both the aperture and shutter remain in place, with the elements coming off a screw "inside the shutter" front tube.
All the elements of the Novar are in front of the shutter blades, and as it is a triplet, un-cemented, then the support rings are all in the front tube part, probably a tube screwed into the shutter/diaphragm front with a step, (or ring),at the back to hold the rear element, then an unscrew threaded spacer, then middle lens and another spacer, and front held by the screwed name ring, or a thin ring underneath it.

The diaphragm is behind the elements or in between the rear and middle, in which case the construction is more complex, and I think the Tenax uses the simpler approach.

All the dis-assembly will only be need if there is lots of dirt or dust internally, it may pay to try cleaning the front and back before any deeper work.

[truls]

Thanks Stephen, I will continue tomorrow as it is evening here now. Here are some pictures from the side of the camera.

Upper side:


Right side (seen from behind the camera):


Left side (seen from behind the camera):


Bottom:

[truls]

As I look at the shots of the lens I see more to unscrew. My eyes are not as they was before...

[truls]

I must be blind... After removing the protruding screws the distanse scale fell off. There a more very tiny screws to take off, i will continue later.

[Rachel]

Truls ...... GULP

[truls]

Rachel, you at Camera Collector has inspired me to dare this. In the end if this can make a tutorial for others we have a success. Time will tell.

Some more progress. So far this has been a fairly simple operation, I believe now comes the hard part. Well, the lens could at this point removed by turning it counter clockwise.

Here we can se the lens taken off:


The lens from behind:


The front:

[mickeyobe]

I have always found dismantling a camera to be a relatively simple procedure.

However, putting everything back where it belongs - with no left over parts - and getting all those parts to do what they are supposed to is where skill comes in and where I too often demonstrate my lack of it.

[Stephen]

You have got the whole lot as a unit, the back has pin holes, you may find fine pliers can turn it, or a home made pin spanner , with steel pins at the right spacing fitted into a metal bar with matching holes, and forced or soldered, or glued into the strip.

The pins should be a tight fit to the recesses, and if a good fit, the bar will act as lever as it unscrews.

The body can be gripped in a Jubilee clip, (adjustable screw pipe clamp), with rubber sheet to protect the lens body, or leather , or thick cloth.



If nothing turns, put a tiny spot of penetrating oil on any visible thread and allow it to work, and try again.

Always examine the whole rim in case there are tiny locking screws in deep tiny holes!!

The name rim should have recesses, if not then try pushing with fine screwdriver, or it might need two holes drilled for a pin spanner, but that is last resort.

Digital shots are cheap, so take as many as possible to work out re-assembly.

[Berndt]

I have always found dismantling a camera to be a relatively simple procedure.

However, putting everything back where it belongs - with no left over parts - and getting all those parts to do what they are supposed to is where skill comes in and where I too often demonstrate my lack of it.

Such a painful truth, experienced so many times

[truls]

I had to unscrew the outside ring, here:


then I had this:


Here is what the inner remainings of the lens looks like:


There is a small screw in the lens, should I disassemble? If this is the aperture will it fall apart or something?


I assume I am ready to shop some detergents now

Also I am concerned of what to do now...

[Stephen]

Unless the iris comes out, which will give access to the back of the two front elements, best clean through the iris, with Q tips Cotton buds, and cotton handkerchief (well washed), with a mix of ammonia and peroxide, with water, the amount to water is up to you, if really dirty it can be use strong, but diluted is more normal.
Go around the lot with a magnifying glass and see if there are more grub screws to release, the iris probably traps the middle element against a spacer, either loose or scrwed on the main thread in the units tube.
In the last shot here appears to be a screw at the left side, is there? ..it may retain the iris plate.
If the plate comes out with blades complete it may be washed in alcohol or thinners or acetone to remove dirt and oil. Be careful if the blades are loose, it will need to be re-assembled carefully.
Once the inner element is released you are there, all surfaces can be cleaned and gently polished, dusted and the whole assembly reversed. The iris should operate dry, adding oil is risky, too much and it can creep, and might get to the glass.
Stephen.

[truls]

GULP

Now ready to clean lens. I am afraid Mickey and Berndt was right, this will maybe never put together again?



It could of course be framed and make a nice view on the wall... In the front we can se the front, middle and rear lens element. The aperture will be a puzzle to assemble.

[mickeyobe]

Oct 9, 2012 7:43:06 GMT -5 truls said:

GULP

Now ready to clean lens. I am afraid Mickey and Berndt was right, this will maybe never put together again?

It could of course be framed and make a nice view on the wall... In the front we can se the front, middle and rear lens element. The aperture will be a puzzle to assemble.

I have confidence in you truls.
At least you know which is the front, middle and rear.

That puts you in the major leagues.

Mickey