Understanding and repairing the mechanical parts of cameras: the biggest challenge?

[Andreas Thaler]

With my cameras from the 1980s, I'm always relieved when there are electronic problems to tackle. You can either solve them or not solve them at all.

However, if the transport, shutter or mirror mechanism is affected, it gets tricky.

Complexity and the need for extensive disassembly awaits you, and who wants to repair a vertical Copal S focal plane shutter with its 1000 parts?

Should I seriously try to repair the mirror box mechanism of a Canon T90?


But these areas seem fortunately to be very stable based on my previous repair candidates.

I only once had a „real" mechanical problem with a Minolta X-700 as far as I can remember:

Minolta X-700 tutorial: Winding lever issue - replacement of Winding base plate B

With intensively used Minolta X-700 it can happen that the winding lever no longer can be locked in the unfolded position. It always folds back into its original position. The winding lever keeps folding back. Not a serious problem, but an annoying one, especially when you want to cock the...

www.photrio.com

And that was relatively easy to solve because the mechanics there are manageable.


However

if I imagine that I had to work on a Nikon F2, for example, which - apart from the light meter - works purely mechanically, I wouldn't know where to start.

The shutter mechanism of a Minolta XG-M looks anything but simple.


That labyrinth full of levers, gears, tiny circlips on axles, various springs and bizarre mechanical components seems to be an enigma.

How can I determine where a problem lies?

Who can help me if I need to solve a mechanical problem with the motor gear box in a Nikon F4?


If I do manage

to find the error, how do I best take this enigma apart?

And how can I adjust a mechanism after assembly?

The service manuals provide instructions on where the tension of springs must be measured or where adjustments in the micrometer range are required, e.g. for the flange focal distance or the mirror of an SLR.

How do I do this?

I don't have a general procedure, a strategy like the ones that exist for narrowing down and fixing (simple) electronic errors.

So what is the best way to proceed with the complex mechanics of a SLR or a pure mechanical camera?

 

[ic-racer]

For this kind of stuff, one needs to make their own repair manual, with either drawings or pictures. Kind of like drawing out a schematic for a device for which a schematic cannot be found.

BTW, did you know that all Rick Oleson's sketches and repair information is now available to download!

 

[Andreas Thaler]

For this kind of stuff, one needs to make their own repair manual, with either drawings or pictures. Kind of like drawing out a schematic for a device for which a schematic cannot be found.

But that doesn't give me a procedure as to where to start and how to go about troubleshooting?

Apart from that, if I take apart a complicated mechanism like the one shown in the pictures above, how do I then go about adjusting it?

Take a look at the springs that are built into the T90 and F4, some of them are monsters, how can I tame them?

 

[Andreas Thaler]

BTW, did you know that all Rick Oleson's sketches and repair information is now available to download!

View attachment 382266

Tech Notes – camera repair download – Rick Oleson BrightScreen

 

[Gregory_Nolan]

The many mechanical aspects are exactly what I like about the F2. When you get your hands on a camera, the first thing you have to do is take stock and see what's wrong. Doing so, I generate a to-do list for the body. For example, if the fast shutter speeds work well, but the slow ones don't, I can narrow down the source of the problem and take a closer look at the slow shutter speed governor. Has a spring come loose? Is the mechanism out of place or dirty? I can check all this and ideally get the camera up and running again quickly. If necessary, I can also open up a working F2 body and compare the mechanical workings - another way of troubleshooting.

If a part is faulty, it can easily be replaced. With the F2 in particular, there is a wide range of defective units from which to source spare parts.

 

[Andreas Thaler]

The many mechanical aspects are exactly what I like about the F2. When you get your hands on a camera, the first thing you have to do is take stock and see what's wrong. Doing so, I generate a to-do list for the body. For example, if the fast shutter speeds work well, but the slow ones don't, I can narrow down the source of the problem and take a closer look at the slow shutter speed governor. Has a spring come loose? Is the mechanism out of place or dirty? I can check all this and ideally get the camera up and running again quickly. If necessary, I can also open up a working F2 body and compare the mechanical workings - another way of troubleshooting.

If a part is faulty, it can easily be replaced. With the F2 in particular, there is a wide range of defective units from which to source spare parts.

This procedure could also be used to test the mechanics of other cameras?

 

[4season]

In the case of the mechanical Copal Square shutter as used in Nikkormat cameras, the info I've gotten to date has suggested "Don't disassemble it, and don't try to readjust it". I think Nikon technicians addressed major shutter faults by simply replacing the entire unit. And yet, you can clean/lube it easily, as critical shutter components are readily accessible without disassembling the module. And yes, I have serviced my own Nikkormat FTn.

IIRC, the service manual for the Minolta X700 mentions that the camera's shutter can, in theory, be serviced, but standard procedure was to replace the shutter assembly as a complete unit, much like the XG-M part in your photo. Although this may sound wasteful, remember that when these cameras were new, parts were a lot cheaper than labor costs.

I have not yet serviced a Nikon F2, but Nikon F is actually very repair-friendly: Although not as modular as Nikkormat, F's mirror box is easily separated from the rest of the camera, and access to the various moving parts is very good.

One difference that I've encountered with older camera designs (Nikon F, Hasselblad V, et al) is that older cameras tend to have more hand-fitted parts: Internal levers may be filed or bent as a means of adjustment, so don't assume that seemingly deformed part is damaged!

 

[Rekusu]

I am at in the early days of figuring out how to dismantle / repair some cameras. Have surprised myself (and a friend whose camera it is) by repairing a Yashica rangefinder. Fitted a new brightline viewfinder mirror and cleaned the Copal shutter.

But what amazes me the most, how did the designers come up with the mechanical ideas to get all the shutter speeds,, timers, springs, levers, etc into such a tight space. I know a watch has a lot of small parts but they are all doing one thing controlling release of energy from the main spring. A camera has many different mechanisms to release energy for the mirror up, shutter open / close and mirror down. I find it incredible.

 

[Tel]

I find electronic circuitry baffling; I like gears and springs and levers because I can see them working and figure out what might be wrong. And I’ve found some good resources online: Robin Guymer’s posts here gave me the confidence to open up an F2 and work on it (the first of six) and Richard Haw’s Nikon page has guided me through several F’s and some S2’s very successfully. The thing that often stops me is curtain shutter replacement. I found the mechanics of the Mamiya C-series TLR’s easy to decipher—they just make sense to me, as do most TLRs. I figured out my Yashica 44’s without any tutorials; the same for a Rollei Baby or two and my primo Jr. Though I have to say that those really tiny leaf shutters on the 127 cameras are so small that I no longer go inside them. I’ve found that fine motor skills diminish as I get older.

Edit: IC Racer, thanks for posting the link to Rick Olesen’s sketches. A great resource.

 

[ic-racer]

To really do a mechanical repair, first one has to either write out or memorize the activation sequence of the camera. One should be able to identify every lever and gear and know to which part of the activation sequence it belongs. Personally I know the Rollei SL35, every lever and gear. I just got a Nikon F and will work on learning that one next. The "F" might be quicker to learn because it is covered in one of the NatCam Teaching guides.

That can be a formidable task, but much easier than memorizing or figuring out every trace on a PC circuit.

This is an example of what it entails:

 

[Tel]

ic-racer: that flow chart looks almost as intimidating as an electronic circuit. But show me a picture of levers and gears and eventually I’ll figure it out. As I read the words in the boxes, pictures of those parts pop into my head. Electrons don’t do that.

 

[ic-racer]

ic-racer: that flow chart looks almost as intimidating as an electronic circuit. But show me a picture of levers and gears and eventually I’ll figure it out. As I read the words in the boxes, pictures of those parts pop into my head. Electrons don’t do that.

Yes, sometimes a picture is better and I make notes like this:

 

[ic-racer]

Sometimes it is hard to give every part a different name, so I use the numbers from the parts manual:

 

[Andreas Thaler]

As I read the words in the boxes, pictures of those parts pop into my head. Electrons don’t do that.

That is the whole principle of moving charge equals current.

A voltage drives electrons through a load, which creates power loss in the form of heat.*

The circuit of an electronic SLR is also based on this principle, but compared to this example, the load is much more complex.

In a mechanism, forces act in different directions and I find this much more confusing and difficult to calculate.

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*In this example 81 milliwatts. This means that energy of 81 millijoules per second is converted into heat.

 

[Andreas Thaler]

To really do a mechanical repair, first one has to either write out or memorize the activation sequence of the camera. One should be able to identify every lever and gear and know to which part of the activation sequence it belongs. Personally I know the Rollei SL35, every lever and gear. I just got a Nikon F and will work on learning that one next. The "F" might be quicker to learn because it is covered in one of the NatCam Teaching guides.

That can be a formidable task, but much easier than memorizing or figuring out every trace on a PC circuit.

This is an example of what it entails:

View attachment 387022

The tool for such charts:

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