leica m6 shutter issue :(

[Rangeman133]

just got a roll of film developed, and was surprised to see a handful of shots underexposed. i couldn't explain it...because it wasn't just one or two, there were about 6 or 7 that were badly underexposed.

just now, i rechecked the shutter's...and found that on 1/4 and 1/8... randomly the shutter would be MUCH faster...sounds like 1/250...and also doesn't have the characteristic 'machine like rumble' when this occurs...otherwise...most of the time, the shutter sounds fine.

also, i can clearly notice the difference in shutter sounds for every shutter speed, but i can't tell the difference between 1/30th and 1/60th...they both sound exactly the same to me.

i'm mainly concerned as to why sometimes, 1/4 and 1/8 shutter speeds open/close MUCH faster (sounds like 1/250)...this definitely explains why some of my shots were underexposed.

has anybody had this problem, or know of it? i bought the m6 in used, but good condition about 3 weeks ago, and have shot quite a few rolls of film already...this is the first time this has happened. from what i know, the camera hasn't been CLA'd...i'm guessing this would be the best option...don't wanna mess with it myself at all!

 

[nobbylon]

The slow speed mechanism needs cleaning and a relube that's all. Try firing it many times right way up and upside down as it may free off with some use.

 

[mooge]

yeah... sounds like the slow speed escapement isn't engaging when it should be.

basically, there's a set of gears that hold back the second curtain for the slow speeds; this set of gears pivots around a point and that's sort of how they provide a range of slow speeds for the shutter. because of the pivoting design, there's not alot of tolerance in the position of the escapement (that set of gears), so when set to certain speeds (1/8 is the most critical!) the escapement might not be in the right position to hold back the second curtain. if your camera works okay at 1/15, 1/2 and 1 but not 1/30, 1/8 and 1/4, that's probably what's wrong.


so it's probably not a bad idea to send it in for repair...

 

[nobbylon]

The escapement is held in place by a spring and pivots freely but held against spring pressure. The problem is the tiny gears run in tiny bearings like a watch and the lube dries out and doesn't allow the gears to run evenly sometimes sticking. It's an easy fix but the top needs to come off. The mech needs washing with lighter fluid and relubing.

 

[mooge]

yes, but it's also possible that the escapement is not engaging with the second curtain- I once had the same problem as Rangeman except it was only 1/8 where the shutter would work like 1/50. the problem had something to do with positioning of the escapement pivot which was affected after I moved something or something. I don't really remember...

but whichever case it is, it should be a pretty simple fix for a competant repair person.

 

[Rangeman133]

^thanks.

i think I'm gonna look into a place to send it to. first time doing this, but i've read that DAG is pretty much the standard place to get camera's and lenses worked on...i've seen other forums which recommend DAG highly...is that still the case now?

thanks again!

 

[jordanstarr]

...what mooge said. I have had my M6TTL opened up and you can easily observe the lever shift once you put the speeds down to (I think) 1/8. The good news is that it looks like an easy fix and if a part is needed, they seem like very simple parts. So, the cost should be relatively low for an experienced tech. Try Youxin Ye, I've never heard a bad thing about his work yet.

 

[ChrisN]

DAG's reputation for top quality work is excellent, but I gather the turnaround can be slow.

I recently had my M4 overhauled for the same problem (and a few other issues) by Sherry Krauter (also a factory-trained Leica technician). The turnaround was a couple of weeks, and the camera now behaves perfectly.

 

[pb908]

have you try some shot with slow speed and camera turn upside down, try it.. If problem reproduce easily, you may have the same problem as i describe in my last post, i think it is possibly a design issue..

 

[pb908]

www.rangefinderforum.com/forums/showthread.php?t=111122
that is the link

 

[nobbylon]

Sorry but this is rubbish. M6's are at least 15 years old now and if infrequently used may need a service. Design fault! Don't make me laugh, it's the same mech as when it first appeared in the 50's. I've fixed many slow speed mechs and it just needs relubing. Unless some bodger has been in there bending stuff!

 

[RFluhver]

I was on the train from Shinjuku when I read this thread. I was trying to control myself not to LOL. What a hoot!! Testing the bloody camera upside down? When does anybody shoot their camera upside down?

Btw, my two M6's don't exhibit this problem.

 

[nobbylon]

I was on the train from Shinjuku when I read this thread. I was trying to control myself not to LOL. What a hoot!! Testing the bloody camera upside down? When does anybody shoot their camera upside down?

Btw, my two M6's don't exhibit this problem.

I'm no camera repairer but I do understand mechanics and I have taken many Leica's apart for fun and laughs aside, this is actually a good way to see if the bearings are becoming sticky. Because the camera spends most of it's life the right way up, the bearings in the top half of the slow speed mech get dry and gummed from under use as the gears are sitting on the bottom plate bearings. It's miniscule tolerances but it does affect the mech when turned upside down. Shoot the first few frames and the gears will settle into the top mech bearings and if gummed will after a few frames start to give erratic times.
I've cleaned many of these mechs now and even after washing in zippo fluid and relubing some have to be washed 4-5 times in clean fluid to get rid of the old lube.
The only mech out of all of my M's to be actually faulty from the factory was an MP. It was sorted by Will van Manen who after washing and cleaning actually figured out that the top plate of the mech was actually not flat but ever so slightly warped. It had been missed by quality control and he ended up having to take the mech apart, re flatten the plate and re assemble. This is much harder than it looks.
As long as an original mech hasn't been damaged or butchered by someone it should only ever need cleaning and relubing.
As a side note the pressure created by the spring on the mech has quite some force to keep it engaged. You would have to physically break or bend something to jam it or have something inside the camera come loose and wedge between it and connecting surfaces. If this did happen no slow speeds would work correctly. If it's erratic times it's the gears.

 

[pb908]

I was on the train from Shinjuku when I read this thread. I was trying to control myself not to LOL. What a hoot!! Testing the bloody camera upside down? When does anybody shoot their camera upside down?

Btw, my two M6's don't exhibit this problem.

you never know until you try my friend.. I have open several m3, and after 50years of usage, none of them have this sloppy 2nd curtain catch.

I just try to convey the message i found during my troubleshooting. I have no problem if everyone laughing at me, as they don't see the problem as I do. Unlucky that a lot of leica user just blind their eyes of any failure possibility. If you have no problem on yours, be happy, just don't laugh untill you test yours