Hasselblad C shutter jammed after service

[ProdigalSun]

Hello folks, I just picked up a 50mm C T* lens with draggy shutter speeds. I opened it up and pulled out the shutter timer, cleaned it up, and oiled it with Moebius watch oil. It now works perfectly. The problem is when I started reassembling the shutter. I had marked the two gears that connect to the shutter pinion wind slot to be sure they were aligned when I put the main drive ring back on. They weren't! And they won't go back into position. I can put the main drive ring back on, but one tooth off (see pics). The pinion slot is also in the wrong position. There is a little bit of play in the gear assembly, but not in the direction I need it to go in order to get the drive ring aligned correctly. I went ahead and put the drive ring, speed selector ring, and lock ring back on and tried to wind the lens. No luck! The shutter seems to be jammed. Any idea what I need to do here? Thanks all!

 

[loccdor]

Pictures after every single disassembly step is the only thing that has saved me.

 

[4season]

Something's off on the shaft end of the small wind gear. IIRC, that's where you determine where the lens-cocking cam clicks into place, and the degree of rotation available. If there's a way to avoid having to re-disassemble that part of the lens, I'm not aware of it. Simply lifting and rotating the small gear never worked for me.

 

[OAPOli]

The problem is that the cocking ring isn't meshing with the main spring cocking gear. Top right on your second photo. They should engage on their first tooth.

 

[BrianShaw]

The problem is that the cocking ring isn't meshing with the main spring cocking gear. Top right on your second photo. They should engage on their first tooth.

This is correct; they are misaligned (although that does not appear to be the entire problem). For the reflex shutters, though, the first tooth sits on top of the land portion of the cocking ring. This is just a bit different from the non-reflex shutters where, as you indicate, the first teeth need to be engaged. This illustration is from Compur and is a reflex shutter and illustrates the relationship described above...

 

[OAPOli]

@BrianShaw you are correct; the gears don't immediately mesh. But they will do so at their first teeth after some dead time in the cycle.

OP I think you need to pre-cock the bottom gear by a tooth and properly seat the cocking ring.

 

[ProdigalSun]

Thanks for the replies! The main spring cocking gear and ring wasn't aligned as mentioned, but that unfortunately doesn't have an effect on the issue. The issue is definitely that the small drive gear is only turning a small amount, and only a small amount counter clockwise. I cannot turn the shutter wind slot (aside from a small amount of slop) whether the drive ring is installed properly or not at all. Any suggestions on how to move forward are much appreciated.

Fig. A - correct alignment of main spring gear. Small drive gear has a small amount of play, but not enough to align marks of the ring with the large gear, much less cock the shutter.

 

[ProdigalSun]

Fig. B - The culprit gear that won't turn aside from a little play. I cannot turn the shutter cocking slot on the back of the lens either (aside from the mentioned small amount of play)

 

[Dan Daniel]

Why are the index marks one tooth off in photo post #7?

Since both of your index marks on the two marks are off, maybe get them both aligned better, move one tooth clockwise on the small gear, which should move larger gear in alignment with the mark on the cocking rack?? Post #7 photo, get marks aligned, not one tooth off.

My mirror sense might be off, but wouldn't moving one tooth clockwise on smaller gear also get slot on back of lens better aligned with red dot? In first photo of thread, the slot is slightly off, top edge centered, not full slot centered.

 

[BrianShaw]

Isn’t there a spring-loaded locking pawl? Could it be jammed, misaligned, or broken?