Leica IIIf - Slow speed adjustment - lock screw is frozen.

Ned Matura · Apr 18, 2020

Hi,
I'm trying to adjust the slow speeds on my Leica IIIf. The setting of 1/4 is firing too fast.
A CLA was done on the camera but the tech was not able to loosen the locking screw and do the final slow speed adjustment. He feels like a previous repair person used Locktite on the screw or over-tightened the screw.
Therefore the 1/4 speed is firing too fast, close to 1/30. The other speeds seem to fire correctly.

Please take a look at the photos of my camera's slow speed dial and the "Slow Shutter Speeds" section of the Leica IIIf Servicing Instructions manual. And where I think the solvent might need to go.

I am not the person who partially stripped the slot on the lock screw. That's why I'm getting the exact size (Screwdriver 3.5 mm dia.) that Leica recommends for this screw head.

I am trying to loosen this locking screw. I have ordered the 3.5mm screwdriver.
I'm wondering if I should use something like WD40, Acetone or Locktite Solvent to help get it loose? I'm willing to take the camera body shell as well as the the front panel with the slow speed dial off of the camera. That will give me access to the front and back of the slow speed dial without there being a chance of solvent dripping into the camera and the shutter curtains.

Anybody have experience with this? Or have an opinion if a solvent might work to loosen the screw?

Any input or opinions would be appreciated.

Thanks, Ned

Louis Nargi · Apr 18, 2020

Send it to D.A.G camera repair don only fixes Leica.

Ned Matura · Apr 18, 2020

Louis Nargi said:
Send it to D.A.G camera repair don only fixes Leica.

Thanks , Louis.
I already asked him and he said that he never had one that didn't turn.
I'm trying to see if I can get it loose before I ask him to do it.
The camera just had CLA and I'd like to not incur another big cost.

awty · Apr 18, 2020

Locktite is designed to unscrew with out too much effort and shouldnt need a solvent.
Dont use WD40 or anything else with oil unless your planning on stripping it all down and cleaning off the oil.
Usually to unscrew anything of that nature, you would secure the camera so it wont move, (a nonslip cloth should be fine) then use the correct sized screw driver and turn anti clockwise while using a downward force on the screw. The downward force prevents the screw driver from stripping the screw. More control if you are standing up.
I take it you loosen B and then adjust C? The only other thing I can think of is that the screw is binding on the setting nut, you maybe able to move the setting nut clockwise slightly with the right tool, but do not force.
Looks like who ever tried unscrewing it didnt do it correctly and butchered the screw, which makes all so much harder now. Perhaps you should find a new camera mechanic.

btaylor · Apr 18, 2020

Locktite comes in many different flavors. At least one of them, Red, is considered permanent. Locktite recommends heating to 500 deg f to break it loose. But apparently they may also make a solvent. A little digging on the ‘net should yield some ideas. Best of luck. It is disappointing to find butchered machines like this.

guangong · Apr 19, 2020

Louis Nargi said:
Send it to D.A.G camera repair don only fixes Leica.

Not quite correct. Don is the go-to guy for Minox. He has also repaired Canon LTM for me. Quality service but sometimes a long wait. He also repairs Leicaflex. Replaced discoloring prism for me.

Ned Matura · Apr 19, 2020

awty said:
Locktite is designed to unscrew with out too much effort and shouldnt need a solvent.
Dont use WD40 or anything else with oil unless your planning on stripping it all down and cleaning off the oil.
Usually to unscrew anything of that nature, you would secure the camera so it wont move, (a nonslip cloth should be fine) then use the correct sized screw driver and turn anti clockwise while using a downward force on the screw. The downward force prevents the screw driver from stripping the screw. More control if you are standing up.
I take it you loosen B and then adjust C? The only other thing I can think of is that the screw is binding on the setting nut, you maybe able to move the setting nut clockwise slightly with the right tool, but do not force.
Looks like who ever tried unscrewing it didnt do it correctly and butchered the screw, which makes all so much harder now. Perhaps you should find a new camera mechanic.

Yes, I’ve found most loctite to be easily undone but I did find out from research that red loctite is supposed to be permanent. I also found out that loctite has a solvent. I see no indication of loctite on my slow speed dial.

I’ve ordered a spare part front plate with slow speed dial to see out how the mechanism is supposed to work and what went wrong with mine.

Ned Matura · Apr 19, 2020

awty said:
Locktite is designed to unscrew with out too much effort and shouldnt need a solvent.
Dont use WD40 or anything else with oil unless your planning on stripping it all down and cleaning off the oil.
Usually to unscrew anything of that nature, you would secure the camera so it wont move, (a nonslip cloth should be fine) then use the correct sized screw driver and turn anti clockwise while using a downward force on the screw. The downward force prevents the screw driver from stripping the screw. More control if you are standing up.
I take it you loosen B and then adjust C? The only other thing I can think of is that the screw is binding on the setting nut, you maybe able to move the setting nut clockwise slightly with the right tool, but do not force.
Looks like who ever tried unscrewing it didnt do it correctly and butchered the screw, which makes all so much harder now. Perhaps you should find a new camera mechanic.

Hey, Thanks for the advice, I'm gathering my tools and getting a spare front plate with slow speed dial from a IIIc to examine closely and see how it should work.

Anybody have a suggestion for where I can get the appropriate tool to adjust the "Setting Ring", Leica part 42 216-446, which is around the screw that seems to be frozen?

Ned Matura · Apr 19, 2020

btaylor said:
Locktite comes in many different flavors. At least one of them, Red, is considered permanent. Locktite recommends heating to 500 deg f to break it loose. But apparently they may also make a solvent. A little digging on the ‘net should yield some ideas. Best of luck. It is disappointing to find butchered machines like this.

Yes, I've seen the loctite solvent. Kind of pricey, $30./ small bottle. I'm going to try and see if there is any locktite in there before I start buying pricey items. Thanks for your suggestion.

StepheKoontz · Apr 19, 2020

Heating and cooling stuck screws can help. I would try heating this up with the tip of a soldering gun.

Ned Matura · Apr 19, 2020

StepheKoontz said:
Heating and cooling stuck screws can help. I would try heating this up with the tip of a soldering gun.

Hey, that's a pretty good idea. Thanks.
I'm going to go examine a functioning spare part from a Leica IIIc and see where to go from there.
The part is coming from Canada and will take a bit of time to get here.

rknewcomb · Apr 19, 2020

on the partially stripped slot on the lock screw, you may want to use a small needle file to clean shape and deepen the slot before you try again so you get a good grip with the screw driver.

StepheKoontz · Apr 19, 2020

rknewcomb said:
on the partially stripped slot on the lock screw, you may want to use a small needle file to clean shape and deepen the slot before you try again so you get a good grip with the screw driver.

A cut off wheel in a dremel tool also works well for this.

Ned Matura · Apr 19, 2020

rknewcomb said:
on the partially stripped slot on the lock screw, you may want to use a small needle file to clean shape and deepen the slot before you try again so you get a good grip with the screw driver.

Yes, a very good idea. Thank you. I wish the tech who couldn't loosen the screw would have been more generous with advice.

Ned Matura · Apr 19, 2020

StepheKoontz said:
A cut off wheel in a dremel tool also works well for this.

Also a good idea, but this piece is extra tiny! Not sure if I could get the dremel in there without damaging something else. But good to keep in mind. Thanks.

John Koehrer · Apr 19, 2020

The heat 'em up method should work OK, the adjustment looks to be a spanner nut and there's a picture of one with a
pliers(spanner) inserted.

From post #5: Locktite recommends heating to 500 deg f to break it loose.

LAST RESORT? Micro Torch!

Ned Matura · Apr 19, 2020

John Koehrer said:
The heat 'em up method should work OK, the adjustment looks to be a spanner nut and there's a picture of one with a
pliers(spanner) inserted.

From post #5: Locktite recommends heating to 500 deg f to break it loose.

LAST RESORT? Micro Torch!

Yes, I'm trying to find pliers/spanner with tips tiny enough to fit.
Need to keep looking.
Heat looks like a later step.
Thanks.

StepheKoontz · Apr 19, 2020

Ned Matura said:
Also a good idea, but this piece is extra tiny! Not sure if I could get the dremel in there without damaging something else. But good to keep in mind. Thanks.
View attachment 244282

Use a worn down cutoff wheel. You will probably cut into the outer ring a bit but...

John Koehrer · Apr 20, 2020

A lot of technicians just grind the plier tips down to fit the holes.

Ned Matura · Apr 21, 2020

John Koehrer said:
A lot of technicians just grind the plier tips down to fit the holes.

Yep, that's an idea. I think I'm going to go with these General Tools 6" divider calipers. They are similar but not as pricey or as sturdy as the Japan Hobby Tools Lens Divider Calipers.

John Koehrer · Apr 22, 2020

I use a set of the General dividers, they flex quite a bit when torqed. I've thought about
putting a brace lower on the leg but don't use 'em that much.

Ned Matura · Apr 22, 2020

John Koehrer said:
I use a set of the General dividers, they flex quite a bit when torqed. I've thought about
putting a brace lower on the leg but don't use 'em that much.

Yep, Judging from their construction and price I imagined they would. For probably using them one time, I think they'll do. Thanks, Ned

Ron (Netherlands) · Apr 28, 2020

So you're sure the screw is loosened when turning ccw? - quite some screws in camera's are not.

Ned Matura · Apr 28, 2020

Ron (Netherlands) said:
So you're sure the screw is loosened when turning ccw? - quite some screws in camera's are not.

Thanks for your comment. Yes, I'm sure. I'm getting a spare part from a Leica IIIc and will confirm it, with this part before I work on my camera. I also got some advice from nobbysparrow who seems to be a good tech in Japan. He posts a lot of "how to, Leica screw mount videos" on youtube. So I'm getting closer to making an effort to "un-freeze" this screw. I'm getting the IIIc part sometime this week, maybe tomorrow. I've got the correct screwdrivers and the correct retaining ring plier tips for adjusting the collar below the lock screw. I'm taking it slow so I don't trash the mechanism or the camera.

Ron (Netherlands) · Apr 28, 2020

Ned Matura said:
I've got the correct screwdrivers and the correct retaining ring plier tips for adjusting the collar below the lock screw. I'm taking it slow so I don't trash the mechanism or the camera.

Welcome and good luck...and I see you have the servicing manual for the IIIC so that is a good starting point. It's been quite a while since I've serviced and restored Leica's, so I wasn't sure about this typical screw anymore. Here a picture of one of the later samples I did - I always took them apart completely
https://www.flickr.com/photos/zorki_2007/albums/72157633280286499/with/8664139350/

Leica IIIf - Slow speed adjustment - lock screw is frozen.

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