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Reassembling hexanon 57mm 1.4 rear diaphragm linkage
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PostPosted: Sat Dec 16, 2023 10:59 am    Post subject: Reassembling hexanon 57mm 1.4 rear diaphragm linkage Reply with quote
Hallo all,

after some time I was able to almost finish the cleaning and repair of this lens.

Alas I needlessly disassembled the rear diaphragm linkage: when opening the flange a bunch of spheres came of and went scattered.

I tried to reassemble this structure but I was unable to put spheres in place, plus the plastic black linkage seems to small to fit into the structure so there is no way to put it all back together, at least for me.

Any help would be appreciated


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PostPosted: Wed Dec 20, 2023 9:29 pm    Post subject: Reply with quote
Just guessing here.

Looks like you have a retaining ring, a ring that moves the aperture coupling deeper into the lens, and a ring to help keep the looks like 6 ball bearings in place.

Maybe plastic ring should have been inserted before some other parts?


PostPosted: Thu Dec 21, 2023 6:06 pm    Post subject: Reply with quote
Ugh, it's almost always a bad idea to disassemble a bearing race on these old lenses, as they are never easy to put back together. At least this one appears to have a relatively small number of ball bearings. In some, you'd be putting 70-80 tiny bearings back in place rather than 6!

Typically, in a race like this one, there is a beveled surface upon which the bearings sit that hold the rotating inner ring in place. Since the contact surface is with the bearings themselves rather than the outer ring, without them in place, the inner part will simply fall through - this is why it seems "too small."

The easiest way to deal with this is to grease up the surfaces so you can place the ball bearings back in with tweezers without them rolling away to who knows where, then once everything is secured, dunk the whole thing in solvent to clear the excess grease out.

In fact, that's probably the best way to clean these in the first place rather than disassembly. Simply put the whole mount in a jar of naphtha or similar and let it soak. If you have an ultrasonic cleaner you cans submerge the jar in while the solvent works, even better. Just be sure to do it outside or somewhere very well ventilated, since solvent fumes tend to be quite flammable and aren't exactly healthy to breathe in, either.

Once everything has been cleaned dried out, put a drop or two of machine oil, 3-in-1, or similar into the race to keep the bearing surfaces from rusting.


PostPosted: Thu Dec 21, 2023 9:38 pm    Post subject: Reply with quote
BrianSVP wrote:
Ugh, it's almost always a bad idea to disassemble a bearing race on these old lenses, as they are never easy to put back together. At least this one appears to have a relatively small number of ball bearings. In some, you'd be putting 70-80 tiny bearings back in place rather than 6!

Typically, in a race like this one, there is a beveled surface upon which the bearings sit that hold the rotating inner ring in place. Since the contact surface is with the bearings themselves rather than the outer ring, without them in place, the inner part will simply fall through - this is why it seems "too small."

The easiest way to deal with this is to grease up the surfaces so you can place the ball bearings back in with tweezers without them rolling away to who knows where, then once everything is secured, dunk the whole thing in solvent to clear the excess grease out.

In fact, that's probably the best way to clean these in the first place rather than disassembly. Simply put the whole mount in a jar of naphtha or similar and let it soak. If you have an ultrasonic cleaner you cans submerge the jar in while the solvent works, even better. Just be sure to do it outside or somewhere very well ventilated, since solvent fumes tend to be quite flammable and aren't exactly healthy to breathe in, either.

Once everything has been cleaned dried out, put a drop or two of machine oil, 3-in-1, or similar into the race to keep the bearing surfaces from rusting.


The most fun lenses are those for which you don't have a service manual, and you try to work out which 4 of the 8 identical looking screws undo the whole mount, and which 4 undo the bearing race retainer in the mount. I had that fun with a Minolta 58/1.2 once. Now I know only to take the 4 long screws out! Wink


PostPosted: Fri Dec 22, 2023 3:21 pm    Post subject: Reply with quote
Very true. The flip side, though, is that it can a great source of ball bearings for aperture detents, particularly the really tiny sub-mm ones like Rokkor lenses often use and that are so easily lost. I took apart a Vivitar Series 1 zoom lens 7 or 8 years ago that provided enough bearings to probably last me a lifetime of lens repairs! There had to have been at least 100 bearings in there.

RokkorDoctor wrote:
BrianSVP wrote:
Ugh, it's almost always a bad idea to disassemble a bearing race on these old lenses, as they are never easy to put back together. At least this one appears to have a relatively small number of ball bearings. In some, you'd be putting 70-80 tiny bearings back in place rather than 6!

Typically, in a race like this one, there is a beveled surface upon which the bearings sit that hold the rotating inner ring in place. Since the contact surface is with the bearings themselves rather than the outer ring, without them in place, the inner part will simply fall through - this is why it seems "too small."

The easiest way to deal with this is to grease up the surfaces so you can place the ball bearings back in with tweezers without them rolling away to who knows where, then once everything is secured, dunk the whole thing in solvent to clear the excess grease out.

In fact, that's probably the best way to clean these in the first place rather than disassembly. Simply put the whole mount in a jar of naphtha or similar and let it soak. If you have an ultrasonic cleaner you cans submerge the jar in while the solvent works, even better. Just be sure to do it outside or somewhere very well ventilated, since solvent fumes tend to be quite flammable and aren't exactly healthy to breathe in, either.

Once everything has been cleaned dried out, put a drop or two of machine oil, 3-in-1, or similar into the race to keep the bearing surfaces from rusting.


The most fun lenses are those for which you don't have a service manual, and you try to work out which 4 of the 8 identical looking screws undo the whole mount, and which 4 undo the bearing race retainer in the mount. I had that fun with a Minolta 58/1.2 once. Now I know only to take the 4 long screws out! Wink


PostPosted: Sat Dec 23, 2023 12:22 pm    Post subject: Reply with quote
BrianSVP wrote:
Ugh, it's almost always a bad idea to disassemble a bearing race on these old lenses, as they are never easy to put back together. At least this one appears to have a relatively small number of ball bearings. In some, you'd be putting 70-80 tiny bearings back in place rather than 6!

Typically, in a race like this one, there is a beveled surface upon which the bearings sit that hold the rotating inner ring in place. Since the contact surface is with the bearings themselves rather than the outer ring, without them in place, the inner part will simply fall through - this is why it seems "too small."

The easiest way to deal with this is to grease up the surfaces so you can place the ball bearings back in with tweezers without them rolling away to who knows where, then once everything is secured, dunk the whole thing in solvent to clear the excess grease out.

In fact, that's probably the best way to clean these in the first place rather than disassembly. Simply put the whole mount in a jar of naphtha or similar and let it soak. If you have an ultrasonic cleaner you cans submerge the jar in while the solvent works, even better. Just be sure to do it outside or somewhere very well ventilated, since solvent fumes tend to be quite flammable and aren't exactly healthy to breathe in, either.

Once everything has been cleaned dried out, put a drop or two of machine oil, 3-in-1, or similar into the race to keep the bearing surfaces from rusting.


Thank you. For brevity I didn't Say that I tried this method, laying the spheres on the bevel they were resting Upon. And there were many more spheres, I Just posted a few of them. It didn't work. Possibly I'm missing some extra retaining ring. I disassembled It being tired after work, that was the real error. Had I been in shape I would have left It intact. I have figured out a special connecting fork that could create a linkage between parts. I Will try to file It out of some sheet metal when I have some spare time. Merry Xmas
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