| Author |
Message |
    
Geowelch
Tinkerer
Username: Geowelch
Post Number: 13
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 22, 2006 - 07:08 pm: | 
|
Some of you may recall my post about Vega 12 80mm lens from a Kiev 6C. (see the thread below for previous history: https://kyp.hauslendale.com/classics/forum/messages/2/8193.html?1166066829)
I dug a little deeper into the Vega 6C, removing the focus ring and helix, which comes off in one unit, after removing three screws around the rear
element.
The aperture blades were completely frozen. Freeing them involved removing and cleaning each blade with Ronsonol, then re-assembling them. Good experience - I now know how apertures work, or how some do anyway.
The diaphragm now opens and closes easily as I turn the ring. Still no response from the button on the rear of the lens mount, which connects to the mirror mechanism in the camera. I've come to the conclusion there is a spring missing from the aperture linkage, but I'm not sure where it should go. The main spring driving the diaphragm blades is working fine. Two possible locations of this hypothetical spring:
1. Just inside the rear cover plate, there is a sub assembly of small levers which transforms rotation of the link shaft to the push-pull of the button. (see first image)
2. There is a collar around the other end of the shaft with a protruding pin which engages against another pin on the arm which opens and closes the aperture. (see second image)
With no spring to provide tension, movement of the arm is not transmitted to the shaft. I've probably over explained my problem, but I was hoping this would sound familiar to someone who has taken apart any Pentacon 6 mount lens. How 'bout you John? ;o)
Image 1:
 |
Geowelch
Tinkerer
Username: Geowelch
Post Number: 14
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 22, 2006 - 07:14 pm: |
|
Here is the second image showing a close-up of the collar and pin. To the left is the other pin, part of the aperture control arm. Please excuse my crude macro photography (8x loupe held against the front of my digital camera).
 |
|
