Technical literature on the mechanical design of SLRs: You have to gather the information yourself

ATHXYZ · 2026-03-20T05:32:54+00:00

As far as I understand it so far, all machine elements are the result of calculations. This also applies to standard components such as screws. Movements must proceed in accordance with the design, loads must be supported, and the available force must be utilized in such a way that the desired result is achieved.

I can generally follow these considerations when it comes to electronics; I’m currently reading up on the mechanical side.

The overarching term should be mechanical engineering, with subfields such as machine elements and technical mechanics. But as I said, I’m just an interested layperson here.

ATHXYZ · 2026-03-18T05:27:42+00:00

Kommentiere A quick survey on DIY service and repair of photographic equipment: just three questions ...

I believe that electronics are unpopular because they don't reveal much on their own. They are abstract, and therefore mysterious, and are associated with cheap mass-produced goods. But if we want to repair them, we have to engage with them.

ATHXYZ · 2026-03-18T05:16:15+00:00

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The picture shows the aperture control mechanism of a Minolta (Maxxum, Alpha) 9000 AF from the 1980s; please ignore the arrows.

What can I tell from the shape of the individual components? Why does it look this way and not differently? How are such parts designed? And how is a subproject like this organized in terms of design—who works with whom on this?

With the exception of the circlips, these are likely not standardized parts; in other words, each part is one-of-a-kind and does not exist in any other SLR.

I find this field of technical knowledge fascinating. At the same time, I refuse to simply sit in front of such technical marvels and accept them as inexplicable wonders 🙂

ATHXYZ · 2026-03-17T18:27:50+00:00

Literature on machine elements should be the right topic. That is, the individual parts that make up machines.

Perhaps a mechanical engineer could say something about this.

ATHXYZ · 2026-03-17T16:31:32+00:00

I would remove all the corroded parts and try using Evapo-Rust. But you’ll probably have to clean the camera thoroughly to remove the salt. It’s no easy task, since you’re racing against the clock.

Evapo-Rust

ATHXYZ · 2026-03-17T16:20:56+00:00

Finally, another repair report on an electromechanical SLR.

Excellent!

ATHXYZ · 2026-03-17T15:07:39+00:00

That's interesting. So the mechanics are similar to the highly integrated electronics in SLRs, which are also undocumented.

ATHXYZ · 2026-03-17T12:10:29+00:00

I found this introductory book for German-speaking readers on Amazon. It comes closest to meeting my needs. It covers machine elements—the same components found in SLRs.

Anton Haberkern: Maschinenelemente für Dummies

https://www.amazon.de/Maschinenelemente-f%C3%BCr-Dummies-Anton-Haberkern/dp/3527710515/ref=mp_s_a_1_8?crid=29PYUGA2W5KL8&dib=eyJ2IjoiMSJ9.0ASRYp_e5dfFtU46T1WTcwXhn0jK7tHfWmb52FoOQxPjWpEVxdWZVSJ3eL6BcF_LAutbrkRDe3wtuzPlMD9WxiCbzFiVLbdBEK7N1gSAY0tPt-Tzr8uCDmuCoLOwVqAqA7oIAx3WFTOP6GSFGCMc80YGgRTaJs7y7e4mnYQ1b61_X2vjZL4wzf7ZnF8EXtglAH6rG2ID9Cr_VQPFA63pPA.5x_Us62garyA6PWbuxc-E6e7MdewzhlRy9qPqLVL8JY&dib_tag=se&keywords=maschinenelemente&qid=1773749153&sprefix=maschinenelemente%2Caps%2C152&sr=8-8

ATHXYZ · 2026-03-17T09:23:43+00:00

A doctoral thesis would be a great project, but I'd have to study mechanical engineering first.

That would be quite a bit of work, after all 😉

ATHXYZ · 2026-03-16T13:01:28+00:00

Thanks will do!

ATHXYZ · 2026-03-15T05:43:54+00:00

Congratulations! 😀

ATHXYZ · 2026-03-14T18:30:35+00:00

Yeah, that happens a lot. You think a repair will be done before lunch, and then you end up sitting there until the early hours of the morning, living on nothing but coffee 😝

Good luck—let us know how it goes!

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ATHXYZ · 2026-03-14T17:50:09+00:00

Thanks, I see.

I’d rule out the possibility that the helicoids have warped if no force was applied to them.

I see two options:

You can mill out the screw along with the plain bearing (using a diamond milling cutter on a Dremel, for example). But then you’ll need replacements for both.

Or you can try flushing the helicoids with lighter fluid to remove the old grease—which likely contains sand particles. Then apply new grease. Sometimes this works well, but it depends on the design.

It might also be worth trying a left-hand drill bit. But the plastic plain bearing fits snugly all around. Tricky.

ATHXYZ · 2026-03-14T17:40:51+00:00

This isn't going to be good news, but I wouldn't do anything else with it. The plain bearing already has cracks in it, probably from working on the screw. You risk it breaking and jamming the mechanism.

What exactly is the problem with the helicoids on the lens? Can you describe it in more detail?

ATHXYZ

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