Emory
Newbie
Several weeks ago, I had a problem with the slow speeds on my Leica III. In the mean time, Dez was kind enough to send me a PM with the solution to the problem. It certainly worked for me, and with Dez's permission, I'd like to share it with those of you who are interested:
NOTE: Dez's text is underlined.
Thanks to the excellent advice offered in this forum, I was able to get the slow speeds on my beloved Leica III (serial number 141351) working like a charm.
The slow speeds all work in any position the camera is held -- with one exception:
In the horizontal (landscape) position, the camera behaves as though it were on "Z" (bulb): The shutter stays open as long as the shutter release button is pushed, closes again only when I let go of the shutter button.
Pushing on the slow speed lifter spring and/or the flat release spring at the bottom often helps. After "fiddling around" with the springs a bit, I can get the slow speeds to work in the horizontal position for dozens and dozens of exposures. But the next morning, after one or two correct exposures, the shutter will once again revert to the "Z" (bulb) behavior.
One note: even when the slow speeds are functioning properly, after letting go of the shutter release button, it often takes a moment before the flat release spring springs back with a slight single or double "clack." (I have tried loosening the screws slightly, then minutely changing the position, but to no avail.)
I am reluctant to take the camera apart. (Although all the external screws appear to be OK, I cannot get the one on the slow speed dial to budge. That means I would not be able to remove the body sleeve.) Is there any way of solving the problem from the bottom of the camera or through the lens mount)?
Having the slow speeds hang until the shutter button is released is a very common problem with old Leicas, and unfortunately there are several possibilities.
The fact that the problem is position sensitive makes it likely that the problem lies with the second curtain release pawl or the spring that holds it in place relative to the rotating shutter mechanism. But before you jump to any conclusions, there are some things to do.
Get some mild solvent, such as mineral spirit. I tend to use watchmakers' ultrasonic rinsing fluid, but that may be a bit more difficult to obtain. You can do a decent partial CLA of the parts of the camera most likely to gum up quite simply.
You really do have to remove the top. The only thing tricky is to ensure that you are able to reassemble the RF windows correctly. There is a rotating wedge lens under the window trim of the wind side RF port. It's a good idea to mark its position before prying it out. This part is used to set the vertical displacement of the RF, and it's fiddly to reset it after servicing.
Hold the camera upside down over a bowl of the mild solvent, and with a small soft brush thoroughly soak the exposed rotating shutter mechanism from every angle, allowing the fluid to drip back into the bowl. Try to keep the camera inverted until it dries, as this solvent can soak the shutter tapes and may even allow them to become detached, which would be the cause of a lot more work. This ensures that the mechanism is moving freely.
The next thing to do is on the bottom of the camera. Depending on the age of your camera it may or may not have a first-curtain brake.
A solvent flush as above is a good idea on the rotating shaft. It is possible, but very unlikely that the adjustable brake is too tight, and it should usually be left alone. However an accumulation of crud under the lifter spring can put excessive force against the pin on the rotating cam and cause trouble at the end of the first curtain's travel. The retarding force of the spring and the shutter brake conspire to slow down the rotating shutter mechanism at the instant it needs momentum to push the second curtain aside and start the slow speeds going.
After all is dry, apply a little bit of very light oil to both ends of the rotating shutter mechanism just where it goes through the body of the camera. About 50% of the time, doing this basic cleaning solves the problem you are seeing.
At this point, you need to carefully study the interaction of the rotating shutter mechanism and the pawl that releases the second curtain. A tiny spot of grease on the place where the rotating cam hits the pawl is in order. The spring locating the pawl is a likely culprit. It needs to apply sufficient force both downwards and toward the front of the camera to keep the pawl in a correct position. The vertical position of the pawl depends on the balance between this spring and the flat spring at the bottom of the camera that provides the resistance to the shutter button. Study the interaction of the rotating cam and the pawl carefully, and see if you find any difference in their relative position with the camera at different angles. There should not be any. You really need to study the operation of this mechanism carefully so you thoroughly understand what each part is doing.
By the way, I am predicating all this advice on the assumption that your slow speed problems also happen at 1/20, and not just where the slow speed escapement is doing its thing. If 1/20 works fine, and the others don't your problem is elsewhere, probably having to do with the lifting of the little flag in front of the rotating shutter cam that engages the slow speeds. Again, studying the interaction between the rotating cam and the bits that interface with it will show you what's wrong. Remember the little pin at the bottom of the camera that pushes on what I called the lifter spring? The moment of the spring is what brings the little flag into position to interact with the shutter cam. Again a matter of the balance between two springs.
One of the above services will in almost all cases solve the problems you are seeing. Otherwise you have more work to do, removing the shell to thoroughly clean the gearing at the bottom of the shutter crate, which is a fair bit of work.
It is actually not necessary to remove the slow speed dial to do any of the servicing I suggested. It is only needed if you are going to remove the body shell.
Since I still cannot get the slow speed dial to budge, I removed the Rangefinder cover according to Dez's instructions above and with the help of this:
http://tunnel13.com/blog/leica-iiia-cla-and-repair/
The hardest part was getting the knurled rings off (I used tiny pliers and masking tape to protect the camera from scratching) and the shutter speed dial (I used heavy garden gloves with rubber nubs),but it was tough going.
Followed Dez's instructions precisely, and cleaning (isopropyl alcohol first, which didn't appear to be as effective as Zippo lighter fluid) and very light oiling as Dez suggested (with a toothpick in my case) did the trick!
I don't have any appropriate grease and was reluctant to use vaseline, so I used a tiny bit of oil instead.
Other than that and the oil on both ends of the rotating shutter mechanism I didn't oil or grease anything. I did, however, brush lighter fluid on a number of tiny shafts both top and bottom after which I continually worked the shutter. This seemed to help a good deal, as the shutter release button now retracts quite smoothly and even after letting the camera sit overnight, I haven't had a single misfire.
Thanks again, Dez!
NOTE: Dez's text is underlined.
Thanks to the excellent advice offered in this forum, I was able to get the slow speeds on my beloved Leica III (serial number 141351) working like a charm.
The slow speeds all work in any position the camera is held -- with one exception:
In the horizontal (landscape) position, the camera behaves as though it were on "Z" (bulb): The shutter stays open as long as the shutter release button is pushed, closes again only when I let go of the shutter button.
Pushing on the slow speed lifter spring and/or the flat release spring at the bottom often helps. After "fiddling around" with the springs a bit, I can get the slow speeds to work in the horizontal position for dozens and dozens of exposures. But the next morning, after one or two correct exposures, the shutter will once again revert to the "Z" (bulb) behavior.
One note: even when the slow speeds are functioning properly, after letting go of the shutter release button, it often takes a moment before the flat release spring springs back with a slight single or double "clack." (I have tried loosening the screws slightly, then minutely changing the position, but to no avail.)
I am reluctant to take the camera apart. (Although all the external screws appear to be OK, I cannot get the one on the slow speed dial to budge. That means I would not be able to remove the body sleeve.) Is there any way of solving the problem from the bottom of the camera or through the lens mount)?
Having the slow speeds hang until the shutter button is released is a very common problem with old Leicas, and unfortunately there are several possibilities.
The fact that the problem is position sensitive makes it likely that the problem lies with the second curtain release pawl or the spring that holds it in place relative to the rotating shutter mechanism. But before you jump to any conclusions, there are some things to do.
Get some mild solvent, such as mineral spirit. I tend to use watchmakers' ultrasonic rinsing fluid, but that may be a bit more difficult to obtain. You can do a decent partial CLA of the parts of the camera most likely to gum up quite simply.
You really do have to remove the top. The only thing tricky is to ensure that you are able to reassemble the RF windows correctly. There is a rotating wedge lens under the window trim of the wind side RF port. It's a good idea to mark its position before prying it out. This part is used to set the vertical displacement of the RF, and it's fiddly to reset it after servicing.
Hold the camera upside down over a bowl of the mild solvent, and with a small soft brush thoroughly soak the exposed rotating shutter mechanism from every angle, allowing the fluid to drip back into the bowl. Try to keep the camera inverted until it dries, as this solvent can soak the shutter tapes and may even allow them to become detached, which would be the cause of a lot more work. This ensures that the mechanism is moving freely.
The next thing to do is on the bottom of the camera. Depending on the age of your camera it may or may not have a first-curtain brake.
A solvent flush as above is a good idea on the rotating shaft. It is possible, but very unlikely that the adjustable brake is too tight, and it should usually be left alone. However an accumulation of crud under the lifter spring can put excessive force against the pin on the rotating cam and cause trouble at the end of the first curtain's travel. The retarding force of the spring and the shutter brake conspire to slow down the rotating shutter mechanism at the instant it needs momentum to push the second curtain aside and start the slow speeds going.
After all is dry, apply a little bit of very light oil to both ends of the rotating shutter mechanism just where it goes through the body of the camera. About 50% of the time, doing this basic cleaning solves the problem you are seeing.
At this point, you need to carefully study the interaction of the rotating shutter mechanism and the pawl that releases the second curtain. A tiny spot of grease on the place where the rotating cam hits the pawl is in order. The spring locating the pawl is a likely culprit. It needs to apply sufficient force both downwards and toward the front of the camera to keep the pawl in a correct position. The vertical position of the pawl depends on the balance between this spring and the flat spring at the bottom of the camera that provides the resistance to the shutter button. Study the interaction of the rotating cam and the pawl carefully, and see if you find any difference in their relative position with the camera at different angles. There should not be any. You really need to study the operation of this mechanism carefully so you thoroughly understand what each part is doing.
By the way, I am predicating all this advice on the assumption that your slow speed problems also happen at 1/20, and not just where the slow speed escapement is doing its thing. If 1/20 works fine, and the others don't your problem is elsewhere, probably having to do with the lifting of the little flag in front of the rotating shutter cam that engages the slow speeds. Again, studying the interaction between the rotating cam and the bits that interface with it will show you what's wrong. Remember the little pin at the bottom of the camera that pushes on what I called the lifter spring? The moment of the spring is what brings the little flag into position to interact with the shutter cam. Again a matter of the balance between two springs.
One of the above services will in almost all cases solve the problems you are seeing. Otherwise you have more work to do, removing the shell to thoroughly clean the gearing at the bottom of the shutter crate, which is a fair bit of work.
It is actually not necessary to remove the slow speed dial to do any of the servicing I suggested. It is only needed if you are going to remove the body shell.
Since I still cannot get the slow speed dial to budge, I removed the Rangefinder cover according to Dez's instructions above and with the help of this:
http://tunnel13.com/blog/leica-iiia-cla-and-repair/
The hardest part was getting the knurled rings off (I used tiny pliers and masking tape to protect the camera from scratching) and the shutter speed dial (I used heavy garden gloves with rubber nubs),but it was tough going.
Followed Dez's instructions precisely, and cleaning (isopropyl alcohol first, which didn't appear to be as effective as Zippo lighter fluid) and very light oiling as Dez suggested (with a toothpick in my case) did the trick!
I don't have any appropriate grease and was reluctant to use vaseline, so I used a tiny bit of oil instead.
Other than that and the oil on both ends of the rotating shutter mechanism I didn't oil or grease anything. I did, however, brush lighter fluid on a number of tiny shafts both top and bottom after which I continually worked the shutter. This seemed to help a good deal, as the shutter release button now retracts quite smoothly and even after letting the camera sit overnight, I haven't had a single misfire.
Thanks again, Dez!
