Olympus OM-1 shutter curtains replacement

[OndrejP_SK]

I had one OM-1 in which the shutter curtains dried out, the ruberized side was full of cracks and generally not as flexible as it should be.


With the 'Camera Craftsman' article and Olympus service manual at hand I managed to replace the curtains.

The original replacement curtains from Olympus would come already attached to the rollers, however I only had spare curtains from broken OM-10 and OM-20(G) bodies.
From OM-10 the opening curtain can be used as it is glued to the take-up roller, but the winding rollers are different and need to be transferred and glued to the original OM-1 winding rollers.
The OM-20 (OM-G) take-up rollers are mounted in the body upside down (the star nuts are up) and therefore can not be used at all.

I used the black curtain from 2 parts bodies. The dotted curtains can be used just as well, and if I ever need to replace the curtains again I will use the ones I have.


The most complicated is to reglue the opening curtain strings to the winding roller. I noted the position of the curtain edge when the string was fully wound to the roller, then when attaching the good curtain I first fixed it only by electrician's tape to find the position for string ends, then checked the position of the curtain edge, then glued both strings at the same line (the strings are same length).


The deeper I dig into an OM-1 mechanism, the more I admire Mr.Maitani and his team for the way they designed the OM-1.

 

[summicron1]

wish they'd stuck to that. I have an om2 that just quit working for no understandable reason. I admire your patience.

 

[Xmas]

wish they'd stuck to that. I have an om2 that just quit working for no understandable reason. I admire your patience.

Your OM2 may have two faults as I think the 1st Curtin should run without a battery. I'll try and get Ricardo to try his without a battery and advise.

 

[Ricardo Miranda]

Hi Noel
Just arrived from Liverpool st. My OM-2N has a roll at the moment. Will try tomorrow when I finish that roll.


Summicron1
What is the OM-2? A -2 or -2N?
They have a reset procedure and it is different in the 2 models.
Have you tried putting fresh batteries in?

Nice article Ondrej!

 

[OndrejP_SK]

An OM-2 is a much more complicated beast. The check procedures are about 2 times longer than an OM-1 because the OM-2 service manual references OM-1 manual for the mechanical parts, and describes electrical checks on as many pages as OM-1 manual describes mechanical checks

However with the right literature and patience even OM-2 is repairable.

BTW: I'm quite new here, can you advise in which section I could post a WTB request to buy 'parts' olympus bodies or at least some particular parts ? I need the switch lever of an OM-2.

 

[Ricardo Miranda]

Hi Ondrej
In other to post here in the Classifieds: Want to buy: (there was a url link here which no longer exists) you have to be a Subscriber, something I don't agree with.
There's plenty of ads on this forum for it to be free. Others, like the British FADU are free.
I don't know where you are, but if you don't have a problem with post from UK, you can try send an email on this website and ask if they have that part: http://www.filmsnotdead.com/

To Summicron1
I tried my OM-2N and the without a battery or a weak one, when you try to take a shot the mirror goes up. the 1st curtain remains in place.
With the -2N you only have to press the lever to check position without batteries to free the mirror. Then out new batteries.
The older -2 has a different procedure described here: http://mir.com.my/rb/photography/hardwares/classics/olympusom1n2/om2/om2manual/index.htm#reset
Good luck!

 

[summicron1]

Thanks, I've tried everything with the OM2n -- fresh batteries, putting the batteries in upside down, swearing, silver oxide batteries, resetting and so on.

The mirror goes up, nothing else happens. First curtain stays put. The battery check light also does not work, even with fresh brand new batteries.

the camera did work, then it worked intermittently, then it quit. A friend I gave it to to fix ("throw it against the wall," I believe was my advice) said he put fresh batteries in it, let it sit, and it worked, then it didn't.

I suspect some sort of electronic gizmo -- a condenser perhaps? -- is not collecting electricity for the camera to use as it should, or something. So at the moment it's a decoration. My friend has a few repair skills, perhaps he can make it go, perhaps not. If he can't, feel free to make me any reasonable offer that covers the hassle of putting it in a box and taking it to the post office.

 

[OndrejP_SK]

OM-2 tend to have oil migrated on the electromagnet. It is possible to clean it after you lift the floor of the mirror box. I tend to use soft paint brush to apply naphta to the electromagnet and then blow it away with rubber rocket blower. It's good idea to remove the bottom also so that the naphta may easily evaporate.

However I still think the first curtain should fire even if the electromagnet is sticky, 'cos the electromagnet controls only the delay of second curtain... Have you checked the action under the bottom cover. What happens when you trip the shutter ? As the mirror reaches the top position it should release the first curtain. If your friend had the mirror box out of the body, he might have replaced it incorrectly and the first curtain fire lever might be misplaced.

 

[summicron1]

As the mirror reaches the top position it should release the first curtain. If your friend had the mirror box out of the body, he might have replaced it incorrectly and the first curtain fire lever might be misplaced.

he hasn't done anything to it yet except replace the battery. If he wants to take the bottom off, that's fine with me. He can use it for a shotgun target. I've washed my hands of it -- I got it for a $50 donation to a good cause, so I'm good either way.

 

[OndrejP_SK]

Now back to the original topic = changing OM-1 shutter curtains, I just tested the shutter speeds. After setting the spring tension enough for the curtain to travel across the film gate in 12ms (as specified by Olympus in the service manual) the speeds 1/60, 1/125 and 1/250 are all within 4% of the correct value! 1/500 and 1/1000 are more than 20% off, but there are separate adjustment points for these 2 speeds by bending parts of the brass high speed selector disc.


BTW: adjusting the speeds should be done by first setting tension to match the 12ms travel time, then adjust slit width at the highest speed which is not individually adjustable (1/250, but on some older samples it is 1/500 like in the following picture) and then the fastest speeds individual adjustment points.

 

[Xmas]

OM-2 tend to have oil migrated on the electromagnet. It is possible to clean it after you lift the floor of the mirror box. I tend to use soft paint brush to apply naphta to the electromagnet and then blow it away with rubber rocket blower. It's good idea to remove the bottom also so that the naphta may easily evaporate.

However I still think the first curtain should fire even if the electromagnet is sticky, 'cos the electromagnet controls only the delay of second curtain... Have you checked the action under the bottom cover. What happens when you trip the shutter ? As the mirror reaches the top position it should release the first curtain. If your friend had the mirror box out of the body, he might have replaced it incorrectly and the first curtain fire lever might be misplaced.

Well I thought that too but Ricardo says not, after he tried it without a battery.

So bad battery contact
bad contact between base plate and chassis
bad corroded battery wire

simple to back off the base plate screws a full turn wriggle base plate and retighten screws

 

[Ricardo Miranda]

Without a current, i.e. without a battery, the -2N only fires the mirror up and that is "safety" measure on the words of the manual.
But, I think Ondrej is talking of a defect on the electromagnet. In that case, he might be right.
My OM-2N electromagnet is in perfect condition.

Ondrej
Is it possible you are confusing with the OM10? Or does the -2N suffers from the same problem?

 

[Xmas]

If the battery test light does bot light it is

Test the battery
Clean the contacts
Back off the base plate screws and retighten
Inspect the battery wire

In that order

 

[OndrejP_SK]

I'm not sure Ricardo. I was just thinking out loud