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I bought the lens with the shutter blades stuck open. The shutter was fitted between an early Fujinon SWD 90mm f5.6 EBC at an attractive price. It turned out t

by foobar1962 5y ago

I bought the lens with the shutter blades stuck open. The shutter was fitted between an early Fujinon SWD 90mm f5.6 EBC at an attractive price. It turned out there were a couple of things wrong. The main one was that lubricants had gummed-up the shutter blades and the slow-speed escapement (that's two separate things wrong). The gummed-up blades had caused mechanical interlocks in the lens to get out of whack and jam the blades open. Soaking the entire mechanism in Shellite (lighter fluid in US) for a day or two unstuck the shutter blades, and some poking-around freed the mechanism. Working the escapement repeatedly has it moving nicely; a bit slow but close enough. Be very careful with lubrication. Some left the factory with none at all, and those places that were lubricated were things like the cocking lever; not the escapements or clockwork. The lubricants used are those used for watches: often whale oil or modern synthetic replacements, not stuff from Bunnings or Supercheap Auto...

brudgers 5y ago
For shutter (and aperture) blades I have used electronics contact cleaner. It's fast and is unlikely to remove lubrication from parts that require lubrication. It is recommended as a first step in a Fix Old Cameras video linked in another comment.
- foobar1962 5y ago
  It's usually the lubricants that cause the problems and need removing: they have either migrated from there there were meant to be, or they have gone hard or gummy. Care with solvents needs to be taken for their effect on non-metal parts. Many recommend alcohol, but it often contains a bit of water and doesn't easily dissolve oils and greases. I've found Sheelite (lighter fluid) to be about the best. For those of a certain age, Freon was the go-to solvent. Ozone layer be damned!
  - brudgers 5y ago
    Freon's properties are somewhat analogous to contact cleaner: an aerosol that dissolves organic compounds and evaporates quickly (Freon boils around -30C). Basically they go where you spray them and are gone before they have time to drip somewhere else.

brudgers 5y ago

For shutter (and aperture) blades I have used electronics contact cleaner. It's fast and is unlikely to remove lubrication from parts that require lubrication. It is recommended as a first step in a Fix Old Cameras video linked in another comment.

foobar1962 5y ago
It's usually the lubricants that cause the problems and need removing: they have either migrated from there there were meant to be, or they have gone hard or gummy. Care with solvents needs to be taken for their effect on non-metal parts. Many recommend alcohol, but it often contains a bit of water and doesn't easily dissolve oils and greases. I've found Sheelite (lighter fluid) to be about the best. For those of a certain age, Freon was the go-to solvent. Ozone layer be damned!
- brudgers 5y ago
  Freon's properties are somewhat analogous to contact cleaner: an aerosol that dissolves organic compounds and evaporates quickly (Freon boils around -30C). Basically they go where you spray them and are gone before they have time to drip somewhere else.