12" Goerz Red Dot Artar, B & T don't work

[johnwe]

I need help getting T and B working. It's in what I think is called a compur shutter. The maximum shutter speed is 1/200

All speeds seem to work and be reasonably close to the correct speed.

If I move the shutter speed ring to B or T and then try to cock the shutter, I can't move the lever to activate the cock the shutter.

If I move the rign to the B setting, when I activate the shutter release lever, the lens will open and stay open. The only way to get it closed then is to move the ring to a shutter speed (not B or T) and then cock the shutter.

I'm somewhat new to this sort of shutter. Am I just doing something incorrectly?

I opened the shutter and took a look, there's nothing that stands out to me that seems out of place. I did not remove the "2nd layer" insider the shutter. only the first cover and then the ring that slidesd to change the speeds was removed.

thanks for reading.

Looking for insight before I send it out for service.

[LabRat]

The T & B are an independent mechanism, that require the shutter to be uncocked when using...

You just leave uncocked, and turn to T & B, and they are activated by the shutter release lever... Shutter stays uncocked when using... And don't cock it in that setting!!!

If they are sticking in those ranges, the arms that activate them need polishing to remove invisible oxides that are very slightly sticky in operation... (No oil or grease!!!) A tiny amount of graphite on the end of the q-tip will do, and careful of the hair like spring that pushes on them... Don't get any graphite anywhere else...

Steve K

[johnwe]

Thanks


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