Compur #3 Shutter Question

[tgtaylor]

I have been having problems with the 360mm f5.6 Schneider Symmar-S on bulb setting in a Compur #3 shutter: When I release the locked cable release, the shutter stays open and I would have to close it manually. This happens on the B setting only and all speeds sound correct and the exposures are accurate. Yesterday I was debating whether to send the lens in for CLA and today, for the first time, I decided to “exercise” all the LF lens by working the shutters a few times. When I got to the 360 everything seemed fine so I installed a cable release and ran through the shutter speeds. Everything worked fine until I got to the B setting and as usual the shutter would open but wouldn't close when I released the lock on the cable release. Then, for some unknown reason, I took the lock off the cable release and the shutter closed each time that I released the plunger. In other words, the shutter remains open when the cable locking devise is used but closes when it isn't used and the plunger is released. Is this the norm for the Compur #3 shutter or is it due to the cable release? The Compur requires a "long throw" release and the 2 that I have are both the same Japanese made cloth covered release that can be found in well-stocked stores.

Thomas

[Drew Wiley]

It's one reason I hated the Compur 3. No actual T setting. But long cable releases themselves can be finicky over time using B settings. Find a clean Linhof or Minolta cable meter instead of the typical camera store type. They were about fifty bucks apiece new, but turn up on the used market sometimes new condition
for around ten bucks average, if I haven't snatched one up first!

[tgtaylor]

Taking a closer look at the cable release the length of the throw is the same if the lock is set or not. The only detectable difference is there is a very slight pull back from the maximum length when the lock is set but no pull back when it isn't. It appears that the slight pull back results in the shutter remaining open when the lock is released. But why would that affect only the B setting? Anyway, I don't have to send it in for a CLA and I can shoot timed exposures with it without having to work the release lever possibly introducing vibration.

Thomas

[BrianShaw]

I've found that cable releases, if the are long in length, can sometimes bind and not fully retract... Especially if coiled or curled. Is yours long?