screwdriver for rangefinder adjustment

[sinjun]

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I'd like to learn to adjust my M9's rangefinder, and have already tinkered with the infinity adjustment, which was slightly out. However, the cam arm is presenting me with some difficulties because I can't get a screwdriver which fits the screw. I've tried 3mm and 5mm offset screwdrivers without much luck - the blades seem too wide for the slot. Can anyone recommend a specific screwdriver to do the job?

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[Lindolfi]

Grind a screwdriver to get a tip of 3 mm wide, 0.25 mm thick and an angle of 20 degrees with the normal. Should work.

[charlesphoto99]

2.5mm works best for me (non-offset).

[sinjun]

Grind a screwdriver to get a tip of 3 mm wide, 0.25 mm thick and an angle of 20 degrees with the normal. Should work.

 

Thanks. What is the best way to grind a screwdriver? I've tried filing one without much success....

[thighslapper]

The ends are usually hardened

Either use a grinding attachment on a drill or heat to red heat to anneal the metal then it will file ok.

Most cheap screwdrivers are rubbish and should file ok anyway.

Remember to file an offset if you are using a straight one as per the adjustment thread .....

 

http://www.l-camera-forum.com/leica-forum/leica-m9-forum/122176-m9-coincidence-infinity-3.html#post1298758

[wlaidlaw]

I would guess Solms have a special tool for the pivot cam screw. I sent my M9 a couple of years ago in for adjustment of the vertical coincidence that was off but I assume they adjusted everything. From the state of the screw in my M9 when it came back from Solms, I am guessing their tool looks something like the image below. If I had been the foreman checking it, I would have told the technician to remove and replace the totally mangled screw.

 

Wilson

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[sinjun]

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I would guess Solms have a special tool for the pivot cam screw. I sent my M9 a couple of years ago in for adjustment of the vertical coincidence that was off but I assume they adjusted everything. From the state of the screw in my M9 when it came back from Solms, I am guessing their tool looks something like the image below. If I had been the foreman checking it, I would have told the technician to remove and replace the totally mangled screw.

 

Wilson

 

I've got one of those! Glad to hear they are capable of mangling the screw in case I end up mangling mine and have to send it in....

[Lindolfi]

Thanks. What is the best way to grind a screwdriver? I've tried filing one without much success....

 

I've used a rotating grinding stone with a very fine grain. You can get nice curved tapering of the screwdriver, improving the grip in the slot of the screw.

[semi-ambivalent]

Thanks. What is the best way to grind a screwdriver? I've tried filing one without much success....

 

I've just adjusted my M3's horizontal displacement. The screw does not need very much torque to turn it so you don't need a high quality tool. This is good because a really cheap screwdriver will have a slightly softer metal and therefore be easier to grind down.

 

I used a 3mm wide blade that had taken on a slightly rounded snout from age. I used a 'fine' flat file and squared up the tip; along and across, if that makes sense. It's really quite easy and took about two minutes (that soft metal again).

 

The slot in the adjustment screw is pretty shallow. That makes the driver fit important, otherwise practically any screwdriver narrow enough would work fine. The other concern is not to apply unnecessary 'upward' pressure on the cam arm. I braced mine with a narrow bit of thin cardboard slipped in between the arm and the lens mount flange. In America it would be known as 'shirt cardboard'.

 

The process is not difficult. Relax, and keep the driver away from the curtains. If film, you can remove the door and lock the shutter open using B and a locking cable release.

 

Good luck, and if you just don't trust your skills take it to a good repair shop.

 

s-a

[Hannes Lummes]

I just successfully adjusted my M's rangefinder. First I made the tools.

Roller offset needs torx tip attached to 90 degrees shaft. Easy.

The cam proportion is not that nice to work with. Since the slot in that screw happens to be aligned directly to the front I decided to grind one screwdriver to somewhat tilted tip and also bend the shaft as much as I felt comfortable. In this way the driver sits nicely in the slot. The screw was not awfully tight.

Adjusting was a bit annoying, because there clearly is some backlash in the small offset plate. So, after a while a noticed that it is necessary to go to one direction only with small steps. If one gets past the right placement then one has to find the backlash again.

Any how. Success. BUT of course now it is evident that all my lenses don't agree with another at all. If I take summicron 50 as the "standard" then my Elmarit M 90 is front focusing badly and Elmarit 28 asph back focusing somewhat. Damned. I guess I have to send them to Germany then. And all legacy lenses are of course totally off.

[Vagabond1031]

On 4/13/2013 at 4:49 AM, Lindolfi said:

Grind a screwdriver to get a tip of 3 mm wide, 0.25 mm thick and an angle of 20 degrees with the normal. Should work.

The smallest kit I can find is 0000 which is 1mm thick or 000 which is 1.5mm thick from https://a.co/d/0MjJb8M

Anyone know where I can get this 0.25mm thick bit size for my M262? 

Thanks