That moment I stopped fighting a sticky aperture blade and fixed the real problem
Been doing this for about 8 years now, mostly rangefinders and old SLRs. Last month a customer brought in a Canonet that was underexposing everything. I spent a whole afternoon cleaning the aperture blades with lighter fluid, checking the linkage, even swapped in a donor blade set from a parts body. Still sticky at f/8 and smaller.
Then I noticed the actuating pin on the shutter housing was dragging just a hair. Took me 20 minutes to file it down a touch and oil the pivot. Works perfect now. All that time I focused on the blades themselves when the problem was one stupid pin I ignored for 3 hours.
Anyone else have a repair where the obvious culprit turned out to be some tiny adjacent part that wasted your whole day?
Wait, you filed the pin? On a Canonet the pin is usually fixed to the shutter housing and the drag is almost always old lube in the pivot. Filing it takes off metal that you cannot put back, and now the blade timing can drift once it wears more. A good flush and a tiny bit of oil at the pivot is what usually frees it up.