ZOMZ Jupiter-3 Clean and Lube, and used for a wartime Sonnar LTM conversion.

Sonnar Brian

Product of the Fifties
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This lens arrived this week- after a lengthy trip from Kazakhstan. The front element has a lot of cleaning marks, but the lens looked new. The focus was "sticky", the lens needed a Lube Job.

This is not hard, but you can get yourself into trouble. As you take a lens apart, make Scribe Marks on the helical before taking screws out. On the J-3, there are multiple starting positions for the outer helical and the fine-thread inner helical. Screws often do best by keeping them in order, so that you can screw them back into the same hole they came out of. Often- grease/grime holds them in, be ready to use Alcohol or Lighter fluid to clean before unscrewing. The set screws are delicate, and the sides will break off.

Three screws hold the focus ring in place. To keep in order: I start with the ones past the Focus Index and keep in order.

RIMG0294.jpg

Once the focus ring is off, the 3 set screws that hold the helical in the mount are visible. The KMZ munt uses 1. Take out the 3 screws, keeping in order. Then- see how much deeper the helical will screw into the mount. This will help you keep track of the correct number of turns when re-assembling. The KMZ focus mount: usually there is none/little margin. This ZOMZ- little margin. I have seen others with almost a full turn.

RIMG0295.jpg

Helical Out.


RIMG0296.jpg


Make Scribe Marks. I use two sets, a "single" and a "Double". This is to re-assemble using the same guide pin for each slot.
RIMG0297.jpgRIMG0298.jpg

Run across ONE J-3 that cannot be reassembled because the screws for each hole are not interchageable, learn this trick...
RIMG0299.jpg
 
This lens arrived this week- after a lengthy trip from Kazakhstan. The front element has a lot of cleaning marks, but the lens looked new. The focus was "sticky", the lens needed a Lube Job.

This is not hard, but you can get yourself into trouble. As you take a lens apart, make Scribe Marks on the helical before taking screws out. On the J-3, there are multiple starting positions for the outer helical and the fine-thread inner helical. Screws often do best by keeping them in order, so that you can screw them back into the same hole they came out of. Often- grease/grime holds them in, be ready to use Alcohol or Lighter fluid to clean before unscrewing. The set screws are delicate, and the sides will break off.

Three screws hold the focus ring in place. To keep in order: I start with the ones past the Focus Index and keep in order.

View attachment 4852350

Once the focus ring is off, the 3 set screws that hold the helical in the mount are visible. The KMZ munt uses 1. Take out the 3 screws, keeping in order. Then- see how much deeper the helical will screw into the mount. This will help you keep track of the correct number of turns when re-assembling. The KMZ focus mount: usually there is none/little margin. This ZOMZ- little margin. I have seen others with almost a full turn.

View attachment 4852351

Helical Out.


View attachment 4852352


Make Scribe Marks. I use two sets, a "single" and a "Double". This is to re-assemble using the same guide pin for each slot.
View attachment 4852353View attachment 4852354

Run across ONE J-3 that cannot be reassembled because the screws for each hole are not interchageable, learn this trick...
View attachment 4852355
Recently did the same with a 1960 ZOMZ lens I have. Although, I think I may have slightly misaligned the RF cam as it’s overshooting at infinity through the finder.
 
Remove the two Guide Pins that hold the helical together.
RIMG0300.jpg
And unscrew it. I dropped the parts in Isopropyl Alcohol to degrease, using a Q-Tip to swab the grease out.
RIMG0301.jpg

RIMG0304.jpg

The innermost helical has a stop screw in a slot- this controls the focus throw and keeps it together. I do NOT completely take it apart, learned the hard way is has a lot of starting positions. It also has two holes for the screw- only one of them is correct. SO: Mark, or Note the hole the screw comes out of.
RIMG0302.jpgRIMG0303.jpg
On this part: the correct screw is near the hole for the set screw of the focus ring.
RIMG0305.jpg

After removing the screw, determine how much farther the ring can screw past the stop. Just in case you separate them- this will help get it back together. I unscrew the innermost helical a few turns, 2 or 3 is safe. I then soak in Alcohol and work the mechanism.
 
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Recently did the same with a 1960 ZOMZ lens I have. Although, I think I may have slightly misaligned the RF cam as it’s overshooting at infinity through the finder.
Is it a aslight overshoot, or "big"?
Did you take the fine-thread helical apart?
Depending on the overshoot- it could be the helical is in too deep in the mount.
 
Without showing pictures, because I was all greasy: I use white lithium grease on the inner fine-thread helical, and a dab on the coarse helical. This lens is buttery Smooth.
I also replaced the J-3 with a wartime Sonnar. This almost never happens, and may be a first-time with a ZOMZ J-3: the original shims of the Sonnar were exact in terms of Focus AND the aperture lining up with the Index. rare. Who ever made this 1971 J-3 was a perfectionist. Thank you.
RIMG0306.jpgRIMG0307.jpg

Wide-Open on the M8.

L1025556.jpgL1025557.jpgL1025558.jpg
 
Is it a aslight overshoot, or "big"?
Did you take the fine-thread helical apart?
Depending on the overshoot- it could be the helical is in too deep in the mount.
I’ll have to double check. I think it’s a fair amount further than a slight. Maybe 4mm overshoot in the viewfinder. I’ve done this before and never had this bother. Although, I’ll admit I was a bit rushed doing this one, maybe I’ve missed the thread I needed. Although, it shouldn’t be too hard as they’re all 100% marked up
 
Still haven’t managed to perfect the shimming process yet. But then I don’t think Xmas holidays with 3 boys under 7 running around is the best time to do it. I need peace. Maybe in 4 weeks when I’m on back shift 😅
 
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