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02-03-2015, 12:15 AM   #1
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Fixing sticky manual focus on a K 200/2.5

Hey friends, I've got a question. I've got a K 200/2.5 that I really like, but I don't use it all that much because the focus is just sticky and slow. I really have to grasp the focusing ring with my whole hand to turn it—nowhere near single-finger focusing on this one. I know it's got a huge amount of glass and metal it's moving so I don't expect it to be silky-smooth, but this is ridiculous. It doesn't feel like a damaged helicoid—if I pull it off the camera and focus it from infinity and back a bunch of times I can feel it 'slip' every once and a while, and it never feels like its scraping against anything when I focus it. So, I figure its something like old grease or something like that.

So here's my question: is there any easy way to un-stickyfy this? I've read various suggestions online of using lighter fluid or wd-40, but I'm not that convinced that's a good idea. I'm not the best with tools (I've purposefully taken apart several old/broken AF lenses before for kicks, but I've never been able to get the back together again) but might be able to do something simple. Or, is it just best to take it in to a repair shop?

Thanks!

02-03-2015, 01:07 AM   #2
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This may be able to shed a little bit of light on your operation (first couple of steps) if you choose that path. There is an article on removing the front element of this lens.
https://www.pentaxforums.com/forums/114-maintenance-repair-articles/179884-pe...-database.html

I would say that the grease has just dried out over time. my suggestion would be to open it up, clean all the old grease off and put some new synthetic grease on the moving parts. I did this for a K28 F3.5 and it was magical to use after that.

Just pouring lighter fluid into it could potentially lead to staining the inside elements resulting in pulling it to bits anyway, and the black paint inside the barrel dissolves with lighter fluid - this could lead to internal reflections where the paint comes off.
Furthermore I am not sure the grease will stay soft as it would presumably return to the same state after the lighter fluid evaporates.

If you do pull it to bits - photograph every stage. That way you can look at the photos for each step along the way.
02-03-2015, 05:21 AM   #3
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QuoteOriginally posted by clawhammer Quote
I'm not the best with tools
You having said that, please send away this fine optical piece of glass for some professional TLC.
02-03-2015, 07:45 AM   #4
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Given the value of that lens (I own one) I personally think it is worth sending it to Eric for a complete cleaning and calibration. If it has dried grease it probably has some other small problem(s) you don't see (yet).

I did that with my K28/3.5. It needed a colimation adjustment - I was never even aware infinity wasn't quite in focus - it came back a different lens.

02-03-2015, 11:10 AM   #5
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Thanks for that link, chaos. I didn't think to search for 'disassembly' While it doesn't look nearly as intricate as the (incredibly cheap) AF lenses I've destroyed for kicks, I have a feeling this shouldn't be my first foray into self-repair, cause then I'd be just as bad as those Canon shooter who mutilate this lens to fit on their cameras. Monocrhome, what was the ballpark cost for your fix?
02-03-2015, 11:27 AM   #6
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QuoteOriginally posted by clawhammer Quote
Monocrhome, what was the ballpark cost for your fix?
< $60 - but that was for that lens at that time. Things might have changed.

Send your lens to Eric for an evaluation. Costs you $15 +/- USPS Flat Rate Insured. He will email you his estimate. If you don't want to pay that he'll send the lens back to you N/C.

FWIW, I have a K35/2 with him for repair of a Canon mutilation, a K200/4 with a locked aperture ring and a Mint- Black MX with dim VF LED's (needs a replacement circuit board).
02-03-2015, 11:32 AM   #7
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Thanks for the info

02-03-2015, 02:49 PM   #8
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The parts that need cleaning and lubrication
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