    
Ronny
Tinkerer
Username: Ronny
Post Number: 1
Registered: 09-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 15, 2008 - 06:31 pm: | 
|
I have a Nikon F which I am trying to restore to working order and the mirror does not return all the down to latch when the shutter is fired. The F parts & repair manual suggests that this might be caused by the main return spring being out of adjustment. The function of this spring appears to be compound in that after the shutter is wound and the spring is held under tension, when the shutter is fired the spring is released raising the mirror then when the tension on the front half of the spring is released the rear half, still under some tension, acts on a pivot to return the mirror to the latched position, except in this case it does not go far enough down to re-latch. The manual gives the proper spring tension as between 600 and 610 grams but as I do not have a proper instrument to check this I hung a coffee can from the lever on fishing line and added small steel washers to it until the lever moved forward, then re-weighed the can but I get inconsistent results. Does anyone know of a more reliable way to do this or perhaps another reason for this particular problem? Thank you. Ronny |
