Olympus OM1 winder/shutter release idler gear screw size

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fenboatman

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Hello. I am trying to resurrect an old OM1 (and an OM10) that I used a great deal in the 1980s. It has been sitting for a good many years and the shutter release is jammed. The winder works. This seems to be a common problem and various videos show a repair involving resetting the position of the idler gear. I tried doing so but in the process managed to drop the screw that holds the gear in place. I have been unable to find a reliable post anywhere that confirms the size although one poster alleged that it's a 2.15 mm diameter screw. Can anyone here confirm that and even better have a recommendation as to where I might buy one? If all else fails, I can buy a donor parts camera but that's an expensive solution for one tiny screw! Thanks in advance for any help you can give me.
 

BobUK

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An old trick is to sharpen a wooden meat skewer, then carefully screw this into the threaded hole. Unscrew the wooden skewer, take your measurements from the new thread formed on the end of the stick. Diameter and thread pitch.
This has worked for me on clocks and cars.
 

julianpa

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Hello. I am trying to resurrect an old OM1 (and an OM10) that I used a great deal in the 1980s. It has been sitting for a good many years and the shutter release is jammed. The winder works. This seems to be a common problem and various videos show a repair involving resetting the position of the idler gear. I tried doing so but in the process managed to drop the screw that holds the gear in place. I have been unable to find a reliable post anywhere that confirms the size although one poster alleged that it's a 2.15 mm diameter screw. Can anyone here confirm that and even better have a recommendation as to where I might buy one? If all else fails, I can buy a donor parts camera but that's an expensive solution for one tiny screw! Thanks in advance for any help you can give me.

You can find small screws in Amazon
 

BobUK

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Click on the link above.

Polar Bear Camera Tools has an excellent range of fine machine screws. Check out the various styles in the index.
 
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fenboatman

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Joined
Aug 11, 2025
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Location
Dunoon, Scotland
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35mm
An old trick is to sharpen a wooden meat skewer, then carefully screw this into the threaded hole. Unscrew the wooden skewer, take your measurements from the new thread formed on the end of the stick. Diameter and thread pitch.
This has worked for me on clocks and cars.

That sounds like a good idea. Thanks.
 
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OP

fenboatman

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Joined
Aug 11, 2025
Messages
4
Location
Dunoon, Scotland
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35mm

Click on the link above.

Polar Bear Camera Tools has an excellent range of fine machine screws. Check out the various styles in the index.

Thanks for that. I had actually discovered this in my searches. I will look more closely once I can identify the screw size and thread. I am assuming it will be a JIS crosspoint but having lost the screw like an idiot I don't have the pattern. I will try the wooden skewer method. Fortunately, I have a digital micrometer.
 

Bushcat

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fenboatman

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Joined
Aug 11, 2025
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Location
Dunoon, Scotland
Format
35mm
Do you have the service manual? I can't decide which component you're referring to, but the service manual should give you the part number, and then Appendix A should give you the screw size. Failing that, it should indicate where else that particular screw is used, so you can remove that one and measure it.


Hi, yes I do have the service manual that I am trying to decipher! I have also established that the OM10 has the same mechanism and I have one of those awaiting repair so will try borrowing a screw out of that and measuring it. That’s if the recalcitrant screws will come out of the baseplate! Thanks for your advice.
 
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