Click stops lost, and Found! Canon 50/1.4 Repair Notes Attached.

ellisson

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A strange noise emerged from my canon 50/1.4 RF lens after I moved the aperture setting to f22. Then, no click stops at the various aperture settings. To make matters worse, when I opened the lens to investigate, the small piece (ball bearing? pin?) that rids over the aperture selection ring probably dropped out on to a nice thick shag carpet! The lens is otherwise in great shape - I hate to use it without click stops - too easy to inadvertenly move the aperture setting.

Is there a decent ending here? Who would have this small part that I probably lost? Any ideas for a fix?

Thanks for considering.
 
First of all you should go over that carpet with a strong magnet. But if that ball is lost, any camera repair (and any model workshop) can source a replacement ball.
 
Bring the lens parts to the camera shop. That ball might be a tight fit and possibly an odd size, too! Lets hope the magnet trick turns up the part, good luck!
 
The ball bearing on the 1950s Voigtlander Noktpm has a spring behind it, and nothing to hold it in place when you remove the optics module from the mount. all i could think of was some engineer got told my his Mom "You're going to shoot out someones eye!" and he did not heed her. Never found it.

If you find it, not hard to put back. On the Canon 50/1.4, it is held in place by a metal bar that is screwed in. It probably came loose. The optics module is held in place by a retaining ring on the back of the lens, surrounds the rear element. Unscrew the retaining ring, optics drops out of the focus mount. The bearing is small, but because of the design, an exact fit is not necessary.

The magnet trick works. I've done it. They are available in the Toy department these days.
 
I don't know what size it is, but if it's 1.5mm, I can let you have replacement. I also have a good BB supplier over here who can source small quantities of odd sized balles (ooer!)
 
Replacement ball bearing

Replacement ball bearing

John,
I believe that is the size. I am interested in getting the replacement part, as I have been unable to locate the one I dropped. I can send you cost and shipping fee for it if you send a pm to me.
Thanks, Gary
 
Thanks to John, who offered to ship a replacement 1.5mm ball bearing for the repair. As it turns out, a California company called Micro-Tools (www.Micro-Tools.com) had these available in packages of 5 for $1. They also have a location in Europe. In any case, the repair was straightforward and I'll post some pictures for anyone who runs into this problem and would like to 'do it yourself'.
Gary
 
Replacing ball bearing for click stops

Replacing ball bearing for click stops

Here are some photos of the repair.

Loosen the retaining ring with spanner, unscrew by hand.

Remove retaining ring and then lift focus ring housing off helicoid.

U-shaped bracket rides over arc in helicoid with grooves for the ball bearing, shown missing in the third image.

Continued...
 

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Replacing ball bearing for click stops, continued

Replacing ball bearing for click stops, continued

Loosen but do not remove the two screws that attach the bracket, and slip a 1.5mm ball bearing under the hole in the bracket (see first image). Make sure the ball bearing is in one of the grooves on the aperture arc, and that it aligns with the correct aperture setting, i.e., with the bearing in the first groove on the arc, the aperture index mark aligns with 1.4 (second image). Some grease can be applied over the arc before reassembling.

When replacing the focus ring housing, note that a groove on its inner surface needs to align with a screw on the helicoid. It's easy to align just by rotating the housing until it slips over the helicoid completely.

Replace the threaded retaining ring by hand, then tighten carefully with spanner. Done!

I hope this helps the next person who encounters this problem!

Gary
 

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  • Slotted inner surface of the housing.jpg
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