I've posted an illustrated narrative on Disassembling and Lubing the Jupiter-3 LTM focus mechanism.
http://ziforums.com/showthread.php?p=1801#post1801
This is about a 1 Hour Job, and makes a world of difference for "sticky/uneven focus".
http://ziforums.com/showthread.php?p=1801#post1801
This is about a 1 Hour Job, and makes a world of difference for "sticky/uneven focus".
jmkelly
rangefinder user
Thank you, Brian - thorough and easy to follow. At least half the J-3's I have ahd in my hands have been gummed up with something - maybe bearing grease, maybe beef tallow
. Absolutely, cleaning this gum out and re-lubing with a modern synthetic makes a huge difference!
What I'm really proud of on this one - getting rid of the 1mm play in the focus. I replaced the undersized guide screws that hold the helical together, and the 1mm play in focus was pretty much gone.
.
.
oftheherd
Veteran
Thanks Brian. Do the other Jupiter 50mm lenses work about the same?
DanOnRoute66
I now live in Des Moines
Have you by chance posted instructions on how to lube a J-9? I have one that is really good optically but it takes almost both hands to turn the focus. I suspect it has the FSU-lubricant-has-turned-to-epoxy syndrome.
The Jupiter-8 is much different, and easier to relube. HOWEVER: not as much flexibility in making RF, focus, and distance scale agree.
Kim Coxon has posted excellent instructions on relubing the J-8 and others on his site.
http://pentax-manuals.com/repairs.htm
Kim Coxon has posted excellent instructions on relubing the J-8 and others on his site.
http://pentax-manuals.com/repairs.htm
Have you by chance posted instructions on how to lube a J-9? I have one that is really good optically but it takes almost both hands to turn the focus. I suspect it has the FSU-lubricant-has-turned-to-epoxy syndrome.
AHA! Kim Coxon site again! Jupiter-9 Lube instructions that I used.
DanOnRoute66
I now live in Des Moines
AHA! Kim Coxon site again! Jupiter-9 Lube instructions that I used.
Sweet! Thanks!
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