Not a rangefinder - Nikon F3 Shutter

D

De_Corday

Eternal Student
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Hello. Long time listener, first time caller.

I have a very, very well-used F3, handed down to me by my uncle. It was his pro-camera for about a decade. Its brassed all over, probably hasn't seen a CLA in years.

The poor thing is shutter capping like crazy above 1/500th. I would like to attempt to fix it myself, as I am fairly handy and have disassembled, fixed, and reassembled DSLRs, small automotive parts, etc etc. But I've never played around inside a film SLR before. I understand that the F3 is a complex camera, compared to something like a Nikormat or a Leica, but I'd like to know what the job would require.

My understanding is that the Quartz timer on the electronic shutter is usually pretty hardy, and that the first step here ought to be cleaning the shutter. I have naptha on hand, I'm ready to give that a try. I just haven't the slightest idea what that kind of a job even looks like--i.e. how to get access to the shutter mechanism.

Anyone care to guide a newbie?
 
Rick Oleson is now on RFF. He really knows his stuff on how to repair classic 35mm cameras. Maybe he'll see your post and chime in.

Jim B.
 
agricola said:
maybe this can help:
http://www.nikonf3.com/f3serv.pdf
Click to expand...

Thanks for the response.

Right now that service manual is the only documentation I've got. Section 2-25 gives me a great view of the shutter mechanism, but in isolation from everything else. I can get to the gear labeled 539 by removing the bottom plate and working around the circuit board, but if I understand what needs doing correctly (and there's a very high probability that I don't), I think I need to be cleaning (or lubricating?) the two curtain take-up reels, which I believe are the cylindrical objects on the opposite side of the assembly.
 
Here's the underside of the camera. I'm assuming the gears in the yellow box are connected to the reels for the shutter curtains, but they didn't move when I test-fired the camera.

The screws in the blue circle are obviously made easy to access, so I'm wondering if they are some sort of adjustment control.

F3_under_zps99153c3c.jpg
 
The brass gears are to adjust the curtain travel time. The curtains should be running at the same speed. Capping happens when one has either sped up or (more likely) slowed down.

The parts in the blue circle are electronic adjustments, don't mess with 'em.
 
Those would be the spring tension adjustment on the curtain spindles, but I would not mess with them, at least not yet. The chances of the spring force having changed appreciably are very slight, so the factory settings should still be correct. Much more likely is that something is gumming up the works and making the first curtain hesitate slightly. It's hard to say where this would be located, it could be a bit of dirt in the mesh of a pair of gears, or rotting urethane from an internal light seal that may have gotten onto the curtain itself (this is a very common problem with the vertical-blade type shutters, not sure if it would be likely on the F3 curtains or not). This is not a job that I would recommend as a first entree into camera repair, but if you've disassembled and reassembled DSLRs this shouldn't be any more difficult. The biggest obstacle in electronically controlled cameras is usually the flexible circuit boards that wrap all the works up like a mummy - often they cannot be gotten out of the way without desoldering their connections.

Fair disclosure: I have done this kind of disassembly on a good number of cameras, but I've never done it on an F3. I very much prefer mechanical machines that don't have all of the PCBs to deal with.
 
Thank you, Rick. Thank you, Landshark.

The electronics I'm comfortable with, its the mechanical elements that are unfamiliar to me. Just about all the light-seals on the camera have disintegrated, and there's practically nothing left to the mirror-cushon, so I strongly suspect that something got gummed up somewhere.

Am I thinking about this correctly that this'll require taking off the mirror block to get at the shutter from the front? Once there, what do I do, just run naptha over every surface and cross my fingers? I'd imagine I'm not doing a whole lot of degreasing or anything, just trying to free up a small amount of grit or gunk...

Part of me thinks the smart move is to buy a very cheap SLR with a focal-plane shutter to practice on before diving into the F3... Any suggestions, anyone? (there are a couple of very beat looking Nikkormats on e-bay for under $20 but I think those have a vertical shutter...)
 
So, sorry to continue being a hamfisted newbie here, but... How do I get the mirror box out of an F3? THe F2's have the screws right there...
 
I'd really suggest getting a donor F3 to work on first before disassembling something with sentimental value.
 
Tomosy's books are good. I don't have that one, but the ones I do have are a good investment.
 
Check ebay if you need another body to work on, some of the prices are really
good, I just got a working nice shape F3 for about $50.00, I always wanted
one years ago when I first saw it in the Nikon House in New York.

Range
 
OK, so here's an interesting twist. I did something I'm pretty sure I wasn't supposed to do... because I can't leave well enough alone, I took a strip of paper dipped in naptha, and ran it around the edges of the open shutter (while the camera was on "T") and along the curtain part of the way into the take-up reel on both sides while the shutter was closed.

The camera responded favorably: with no lens and the camera pointed at a white computer screen, I've been testing for capping. It used to happen 8 out of ten exposures at 1/1000, and 1/2000 was useless. now, about 9 out of ten exposures at 1/2000 work without any shutter capping!

EDIT:
However, thats only if I fire off the exposure immediately after cocking the shutter. If I work the advance, and wait a beat or two, then press the shutter, the seems to be a 50/50 chance it'll cap.

I'll keep exercising the shutter, but... any ideas?
 
Update:

A little bit more naphtha force-feeding and the shutter stopped capping. No idea if the timing is accurate, but I threw a cheap roll of film in there. If the roll comes out OK, great. If the exposure is off (which I suspect it will be), Maybe I should just quit penny-pinching and get it a proper CLA. If the capping returns, well...

Anyway, thank you all for your assistance. Hopefully I'll win one of the F2's or F3's I'm hunting on ebay at the moment, and then I'll be asking for yet more disassembly assistance.
 
De_Corday said:
So, sorry to continue being a hamfisted newbie here, but... How do I get the mirror box out of an F3? THe F2's have the screws right there...
Click to expand...


Uhhhhhhh!
Not the suggested starting point at all.

I disagree with rick about changing tension on the curtains though. There have been far too many older cameras where this has been the solution.
 
Landshark said:
Uhhhhhhh!
Not the suggested starting point at all.

I disagree with rick about changing tension on the curtains though. There have been far too many older cameras where this has been the solution.
Click to expand...

I stopped myself before doing something (more) stupid.
 
I would like you said try out the camera, did you take a blower bulb and blow around
the shutter, it's a small point but sometimes it helps. Has the camera been sitting
around a long time?

Range
 
Range-rover said:
I would like you said try out the camera, did you take a blower bulb and blow around
the shutter, it's a small point but sometimes it helps. Has the camera been sitting
around a long time?

Range
Click to expand...

Before I got my hands on it, It sat for probably ten years. Before shooting it I took a blower bulb to it, and I "exercised" the shutter a bit, probably working it about 200 or so times before loading it up with film.

Come to think of it, there was one concerning thing... when my uncle pulled it out of his box of old cameras, the shutter was cocked... would this, theoretically, cause the first curtain spring to lose tension relative to the second curtain spring?
 
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