Nikon FG sticky shutter
I was given an FG the other day. Cosmetically it's great, looking basically like new, but it has some issues. The mirror, prism and eyepiece lens were all hazy, and of course all the seals and foam had turned icky. I spent a pleasant evening pulling the top off, removing the prism, and cleaning all the surfaces, then cleaning out all the old foam and replacing it.
So now it's nice to look through, but the shutter is sticky. If I set the speed to say 1/4 and trip the shutter, the mirror pops up and the shutter opens, then 1/4 second later I can hear the second curtain trip, but it takes a second or two before the shutter actually closes and the mirror drops back down.
I noticed the shutter blades weren't perfectly clean, so I tried flooding them with isopropyl using a cotton bud and exercising the shutter. It fired nicely while the shutter was damp with isopropyl, but as it started to evaporate became increasingly sluggish, at one point taking about five minutes before the shutter closed.
I'm guessing that I really need to pull the shutter assembly out to ascertain what's sticking. From reading my nikon repair book, that will necessitate pulling the top off again, and then pulling the lens mount, aperture resistor and mirror box, which looks like a mammoth job.
I confess I'm starting to get frustrated with this one - it's a camera with zero value. It's tempting to admit defeat and move on.
Does anyone know any possible shortcuts for ungumming shutter assemblies?
John, Mount Vernon, Virginia USA
Try using Naptha rather than alcohol. It cleans better and evaporates faster. I use coleman lantern fuel, just a fancier can.
You should be able to operate the shutter with the back open by wedging the counter sensor with a tooth pick & advancing the counter to #1. Then you should at least see part of the operation.
I also think that if this were in a shop it would be beyond economical repair because if the flushing doesn't clear it up it wouldn't be worth the time to disassemble the shutter, or the cost to replace it.
Last edited by John Koehrer; 02-04-2010 at 12:26 PM. Click to view previous post history.
Debris from the degraded foam has almost certainly found its way into the shutter.
Any solvent will only spread it out and move it around. Years ago just for curiosity, I removed a similarly-affected shutter and immersed it in solvent - while immersed I cocked & fired the shutter many times, tried (carefully) jetting & brushing solvent into the edge of the housing. In total the shutter was submerged for hours in a very effective solvent, cellulose thinners.
When removed & dried there was a slight improvement but not enough to be of any use whatever - I still had to strip it to clean it properly.
Unless you can do this yourself your camera is definitely well beyond economic repair.
Another thought - the camera has no value and you said you enjoyed working on it.
Although it was my living I always found camera repair therapeutic until my eyes & fingers grew old. Loved the work in fact.
Maybe you would too? If you're good the returns are excellent.
Most people don't have the patience or method to succeed but you seem to have potential!
BTW I did at the time wonder whether a vibrating table or container for the solvent might work...but stripping & rebuilding a shutter isn't that hard and I could then offer my usual guarantee with confidence.
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Okay, I gave is my best shot. I carefully disassembled it and took about thirty photos of the process.
Here's one, showing the intricacy of the mechanics and electronics surrounding the rewind crank:
Not long after I took this photo, I decided enough was enough, and harvested the camera for useful screws etc.
Basically the shutter didn't respond to cleaning. It just got slower and gummier. I think I really needed to pull it out and drop it in an ultrasonic tank. But in order to get it out, I'd have needed to fabricate a special tool, as one of the screws holding it in was rather strange.
So at this point, I decided it was of more value for its fasteners etc than as a camera. I harvested all the screws, put the shiny new lens mount on my FE2, played with the naked prism, and binned the rest.
Did your FG have that little screw on finger grip on the front below the shutter release? If so, is it retrievable from the bin? And if the answers are yes so far, any chance that I could have it/buy it from you?
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.
Yes it did, yes I just retrieved it, and yes you can have it, but I won't accept any money for it. Send me an address and I'll post it to you.
Last edited by suzyj; 02-06-2010 at 10:46 AM. Click to view previous post history.