Leica coupling arm stuck

[Herman Zhang]

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Yesterday, while I was using my M240, the coupling arm was stuck and it wouldn't bounce back to the normal position. I fixed it, but it happened about 3 more times that morning. That no longer happens today for some reason. I went to the Leica store, and their response to this is that the weather is too cold and it might have froze and jammed the arm. What do you guys think? it is a very old camera, so it might be the lubricant's problem. Did any of you ever had this problem?

[a.noctilux]

Well know problem quickly solved.

A very tiny drop of right lubricant ...

[jdlaing]

11 hours ago, a.noctilux said:

Well know problem quickly solved.

A very tiny drop of right lubricant ...

Maybe in a film body but I wouldn’t dare in a digital body. If I remember correctly most of those stuck arms came from incorrectly mounting a lens and striking that arm. These Leica bodies are pretty well designed and built but they are not cast iron.

[Mute-on]

1 hour ago, jdlaing said:

Maybe in a film body but I wouldn’t dare in a digital body. If I remember correctly most of those stuck arms came from incorrectly mounting a lens and striking that arm. These Leica bodies are pretty well designed and built but they are not cast iron.

This is not accurate. In fact it is perfectly within the capabilities of most users to fix the stuck arm on an M240 (and other digital Ms), since removing the top plate requires no special tools. 

[Mute-on]

22 hours ago, Herman Zhang said:

Yesterday, while I was using my M240, the coupling arm was stuck and it wouldn't bounce back to the normal position. I fixed it, but it happened about 3 more times that morning. That no longer happens today for some reason. I went to the Leica store, and their response to this is that the weather is too cold and it might have froze and jammed the arm. What do you guys think? it is a very old camera, so it might be the lubricant's problem. Did any of you ever had this problem?

See this thread and links for the solution…

https://www.l-camera-forum.com/topic/326895-focusing-with-my-m10-d-seems-to-freeze-literally/#comment-4927132

[jdlaing]

14 hours ago, Mute-on said:

This is not accurate. In fact it is perfectly within the capabilities of most users to fix the stuck arm on an M240 (and other digital Ms), since removing the top plate requires no special tools. 

You don’t need to remove the top plate to fix the arm. Also….my post above was in reference to lubricants not user capabilities.

[Herman Zhang]

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I gave it to Leica store in Tokyo and they fixed it for me, but Jdlaing, you mentioned that it is mainly caused by mounting the lens incorrectly. Can you tell me how you mount it correctly then?

On 12/21/2023 at 9:29 AM, jdlaing said:

Maybe in a film body but I wouldn’t dare in a digital body. If I remember correctly most of those stuck arms came from incorrectly mounting a lens and striking that arm. These Leica bodies are pretty well designed and built but they are not cast iron.

 

[jdlaing]

9 minutes ago, Herman Zhang said:

I gave it to Leica store in Tokyo and they fixed it for me, but Jdlaing, you mentioned that it is mainly caused by mounting the lens incorrectly. Can you tell me how you mount it correctly then?

 

You line up the red dot on the lens with the red dot on the mount. That lets the roller cam on the arm into the round cutout on the lens in the right position without banging in to it. If you were to push back on that roller cam at the end of the arm hard enough it would jam it. 

[jdlaing]

15 minutes ago, Herman Zhang said:

I gave it to Leica store in Tokyo and they fixed it for me, but Jdlaing, you mentioned that it is mainly caused by mounting the lens incorrectly. Can you tell me how you mount it correctly then?

 

PS: After a while you might detect what position that round notch on the lens mount is in as you mount it and it becomes second nature to tell what position it is in and you learn to use that instead of lining up the red dots. 

[Herman Zhang]

The staff in the Leica store told me to set the focus to infinity and then mount the lens, is there any reasons to that?

[jdlaing]

12 hours ago, Herman Zhang said:

The staff in the Leica store told me to set the focus to infinity and then mount the lens, is there any reasons to that?

I don’t know about that as an advantage when mounting a lens unless it indexes the focus cam. I do, however, keep my rangefinder lenses on infinity as I use that in manual focusing. I only have to rotate the lens in one direction to focus. It’s faster for me.

[a.noctilux]

On 12/22/2023 at 3:31 AM, Herman Zhang said:

The staff in the Leica store told me to set the focus to infinity and then mount the lens, is there any reasons to that?

When set to infinity, the len's coupling device is the most up front, this is a second nature of long  time M user (...just something done mechanically, I don't know from when in my case).

[Pyrogallol]

On 12/22/2023 at 2:31 AM, Herman Zhang said:

The staff in the Leica store told me to set the focus to infinity and then mount the lens, is there any reasons to that?

I would have said the opposite, set the lens to the closest focussing distance, Mount it on the camera and then refocus to infinity. That is needed with mounting some Russian Fed/Zorki lenses to let the cam follower arm engage correctly with the lens.