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10-30-2020, 06:19 PM   #1
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relubricating Kiron (Lester Dine) 105mm f/2.8 Macro?

Well, I'm back to the advice trough for more help with this lovely lens. Having cleaned a hazy element last time with help from this forum, my new goal is to redo the lubrication of the focus helicoids. The focus action on my copy is smooth and very well-damped, but stiffer than I like. I did read somewhere or other that Kiron may have intentionally tuned the lubrication on this lens to be rather stiff straight from the factory for the sake of maintaining focus once it's set... but who knows if that's a reliable report? I wonder if anyone reading this is/was an original owner of this lens, and if they remember the focus action always being stiffer than is typical for a manual-focus macro lens....

Anyway, my difficulty is that I can't figure out how to separate the helicoids. I need to do that in order to clean the old grease off and put new grease on in an appropriately small amount. I have tried softening the old grease with a bit of lighter fluid, but that didn't change the resistance.

The outer helicoid keys were easily removed. But that didn't let me unscrew the inner barrel from the outer. I think I need to remove the name ring at the front of the outer barrel, which seems to act like a retaining ring for the inner barrel. However, I can't figure out how to remove this ring! I thought I could just twist it off. There is a screw just aft of the ring that seems like it might be involved in keeping the ring in place, but removing this screw didn't make it any easier to twist the ring off. I also applied acetone to the tiny gap between the name ring and the outer barrel, to no avail.

Has anyone taken this lens apart? Thanks is forthcoming.

10-30-2020, 09:21 PM   #2
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Not really helpful, but I never figured out how to get mine apart. Because of that, I decided to live with the super stiff focus ring on my Panagor 90mm f2.8, also Kiron-made.

Maybe it fixed itself in the drawer!

Nope.
10-30-2020, 09:26 PM   #3
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QuoteOriginally posted by Just1MoreDave Quote
Not really helpful, but I never figured out how to get mine apart. Because of that, I decided to live with the super stiff focus ring on my Panagor 90mm f2.8, also Kiron-made.

Maybe it fixed itself in the drawer!

Nope.
I appreciate the reply!
10-31-2020, 12:32 AM   #4
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If you're not removing the grease, lighter fluid is probably the one of worst things you can put on it. Lighter fluid has high volatility / low evaporation point. It will dissolve the oils in the grease then evaporate leaving behind the carrier, usually clay of some sort. The result is the action becomes even stiffer.

10-31-2020, 12:41 AM   #5
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QuoteOriginally posted by Not a Number Quote
If you're not removing the grease, lighter fluid is probably the one of worst things you can put on it. Lighter fluid has high volatility / low evaporation point. It will dissolve the oils in the grease then evaporate leaving behind the carrier, usually clay of some sort. The result is the action becomes even stiffer.
Well, I guess I won't be doing that again.
10-31-2020, 10:05 PM - 1 Like   #6
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@Just1MoreDave I just noticed the distance scale on one my Lester Dine's is way off. Instead of infinity it is set to around 1.2 meters. It is focused at infinity when turned down to the stop.

Did you happen to notice which set of screws affected the distance scale setting? There are three sets of screws visible. Three tiny slotted screws on the name ring at the end of the focus barrel. A single large cross-headed screw on the barrel. And on the distance scale there are three slotted grub screws. From what I've read there are no screws under the rubber. I suspect the three screws on near the distance scale would do the trick but any insight you have from your attempts would be appreciated.

Damping is acceptable for me.

Note: https://groups.io/g/KironKlub might be the place for some inquiries as there maybe be someone there who as some experience disassembling these lenses. Formerly a Yahoo group it was migrated to a new platform when Yahoo started shutting down their groups. The founder Kron Kid is/was a Pentax user.

Last edited by Not a Number; 10-31-2020 at 10:18 PM.
10-31-2020, 10:17 PM   #7
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QuoteOriginally posted by Not a Number Quote
@Just1MoreDave I just noticed the distance scale on one my Lester Dine's is way off. Instead of infinity it is set to around 1.2 meters. It is focused at infinity when turned down to the stop.

Did you happen to notice which set of screws affected the distance scale setting? There are three sets of screws visible. Three tiny slotted screws on the name ring at the end of the focus barrel. A single large cross-headed screw on the barrel. And on the distance scale there are three slotted grub screws. From what I've read there are no screws under the rubber. I suspect the three screws on near the distance scale would do the trick but any insight you have from your attempts would be appreciated.

Damping is acceptable for me.
Even before reading your reply, i saw those three tiny set screws just afore the distance scale and suspected they were for calibrating the scale. I'll try to confirm this later.

---------- Post added Oct 31st, 2020 at 10:36 PM ----------

QuoteOriginally posted by Not a Number Quote
Did you happen to notice which set of screws affected the distance scale setting? There are three sets of screws visible. Three tiny slotted screws on the name ring at the end of the focus barrel. A single large cross-headed screw on the barrel. And on the distance scale there are three slotted grub screws. From what I've read there are no screws under the rubber. I suspect the three screws on near the distance scale would do the trick but any insight you have from your attempts would be appreciated.
Sadly, my only screwdriver that fits these tiniest of set screws was unequal to the task. When I applied enough torque to loosen the screws, the driver's shaft started spinning freely, unmoored from the handle. Time to buy a new screwdriver.

QuoteOriginally posted by Not a Number Quote
Note: KironKlub@groups.io | Home might be the place for some inquiries as there maybe be someone there who as some experience disassembling these lenses. Formerly a Yahoo group it was migrated to a new platform when Yahoo started shutting down their groups. The founder Kron Kid is/was a Pentax user.
Thanks for the link! I'll give them a try.

10-31-2020, 10:54 PM - 1 Like   #8
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QuoteOriginally posted by argoyle Quote
relubricating Kiron (Lester Dine) 105mm f/2.8 Macro?
I came across some relevant materials a few weeks ago regarding disassembly.

Lester A. Dine/Kiron 105mm Macro Lens Front Element Removal

PF member @marcusBMG was the OP for the above thread and may remember some of the particulars.


Steve
10-31-2020, 11:02 PM   #9
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QuoteOriginally posted by stevebrot Quote
I came across some relevant materials a few weeks ago regarding disassembly.

Lester A. Dine/Kiron 105mm Macro Lens Front Element Removal

PF member @marcusBMG was the OP for the above thread and may remember some of the particulars.


Steve
Thanks, Steve. I had already read that thread and not found in it any help for removing the branding ring (on which the lens name is actually engraved, not the nameless "name ring" mentioned in the thread). However, you did just now remind me to try and contact the last commenter in the thread, "lucca1x", who, judging from the pictures he posted, must have succeeded in removing the branding ring.
10-31-2020, 11:05 PM   #10
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QuoteOriginally posted by stevebrot Quote
I came across some relevant materials a few weeks ago regarding disassembly.

Lester A. Dine/Kiron 105mm Macro Lens Front Element Removal
I ran across that a few hours ago. Unfortunately removing the front element doesn't help with the helecoid assembly.

For note most of the Lester Dine versions of the lens do not have the built-in hood. And at least on one of mine the filter ring holder just screws off. Mine unscrewed one time when I tried to remove the macro ring light which was jammed on the threads.
11-01-2020, 10:34 AM - 1 Like   #11
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Ok, I took a chance and backed off the screws near the distance scale a turn or so. The scale rotated more or less freely so I was able to set it the same on infinity as my other lens. The ring wouldn't slide, perhaps you have to back the screws out more.
11-02-2020, 08:52 PM   #12
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Might be some locktite where that name ring is and some heat could help? I was going to suggest the keys but it seems like you got to those already.

Keep us posted!
11-02-2020, 09:06 PM   #13
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QuoteOriginally posted by FotoPete Quote
Might be some locktite where that name ring is and some heat could help? I was going to suggest the keys but it seems like you got to those already.

Keep us posted!
It's not going well. I bought an appropriately-sized filter wrench to provide increased grip and leverage. Even though it's rubber-clad, it slipped on the very smooth branding ring when i squeezed hard and turned. Then i tried wrapping the ring in double-sided tape to prevent slippage. It did do that quite well, but i still could not get the ring off despite applying as much torque as i could muster. This sucker is screwed on really tight. I also tried dripping acetone into the gap to soften any thread-lock: no dice. Same for applying heat with a hair dryer.

I'm just about resigned to living with the stiff focus action.
11-02-2020, 09:09 PM   #14
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QuoteOriginally posted by argoyle Quote
It's not going well. I bought an appropriately-sized filter wrench to provide increased grip and leverage. Even though it's rubber-clad, it slipped on the very smooth branding ring when i squeezed hard and turned. Then i tried wrapping the ring in double-sided tape to prevent slippage. It did do that quite well, but i still could not get the ring off despite applying as much torque as i could muster. This sucker is screwed on really tight. I also tried dripping acetone into the gap to soften any thread-lock: no dice. Same for applying heat with a hair dryer.

I'm just about resigned to living with the stiff focus action.
Hmm sometimes, turning it the other way or twisting it back and forth in small increments can help loosenand break the bond.

But I suppose better to play it safe until you find more info online or maybe exploded diagrams to know for sure.
11-02-2020, 09:21 PM   #15
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QuoteOriginally posted by FotoPete Quote
Hmm sometimes, turning it the other way or twisting it back and forth in small increments can help loosenand break the bond.
Worth a try. Thanks
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