Sticky Synchro-Compur Shutter

[Mark_Turner]

I'm using a borrowed Schneider Symmar 1:5.6/150 mounted in a Synchro-Compur shutter. Today, while out in the cold air making a few images, the shutter failed to open on "T" after working properly (I think, since I haven't processed the film yet) for my first two set-ups. So I packed up and came back to my studio.

I did a little testing, and found that the shutter somewhat randomly opens when triggered. The response is the same across multiple shutter speeds from T to 400. Sometimes the blades open and sometimes they don't. The sound of the gear train seems pretty normal.

My initial thought was that the shutter doesn't like the cold, although it worked properly outside in cold air on Saturday.

Any thoughts before I send it to a competent repair shop in Seattle (closest place for such things)?

[Mark Sampson]

The lubricant in the shutter has turned into tar- dirty tar at that. The springs and gears are fighting through it, with unpredictable results.
Any competent repair shop can fix it. It's not yours, so don't try and take it apart yourself.
Flooding it with lighter fluid (as some people will tell you to do) only postpones a proper service, and can do more harm than good.
That shutter is a precision instrument, and they aren't making any more of them. Take care of it and it will take care of you!

[BrianShaw]

“ Flooding it with lighter fluid (as some people will tell you to do) only postpones a proper service,”

That’s especially true with Synchro-Compur shutters.

[Mark_Turner]

Flooding it with lighter fluid (as some people will tell you to do) only postpones a proper service, and can do more harm than good.

I hadn't even heard of the lighter fluid idea, and definitely won't try it. Off to the repair shop it goes, on behalf of my friend who owns it (and doesn't want to sell it to me without the monorail camera I don't want). I've got my own 150 on order.

[domaz]

Synchro-Compur are probably the most DIY unfriendly to repair of any shutters. Don't ask me how I know...

[paulbarden]

Synchro-Compur are probably the most DIY unfriendly to repair of any shutters. Don't ask me how I know...

I service at least two per week and I don't find them "unfriendly" to work on. Perhaps because I am very familiar with them?

[BrianShaw]

I service at least two per week and I don't find them "unfriendly" to work on. Perhaps because I am very familiar with them?

Yes

[LabRat]

The biggest problem with these shutters is they are mostly unlubed, dry metal to metal sliding contact points that oxidize over time, and the oxidation can be slightly "sticky" or micro rough, preventing free movement... These need to be carefully de-oxidized to allow free movement... Lubes and cleaners will leave a slight residue that will gum up these areas, so a through removal is needed...

These are built to very tight tolerances, and even a trace of oxidation will impede operation...

The good news is the oxidation builds very slowly over time, so once cleaned properly (by an experienced pro), it should run for decades before another overhaul is needed...

Steve K

[Havoc]

The biggest problem with these shutters is they are mostly unlubed,

That is not what the service manual says, there are plenty of lubricated surfaces and parts in there.