synchro compur shutter repair

[wgyang]

Hi folks, I am new to this forum. I am wondering if I can get some advice from you on repairing a compur shutter. I got a #0 synchro compur shutter whose cocking lever is jammed. After I striped down the shutter, I found the cocking ring and the pinion gear for the main drive cam do not have a tight contact as shown in the picture. The space makes the cocking lever slip. Did anyonee encounter similar problems? I am wondering if the space between the teeth can be adjusted or it just indicates the cocking ring or the pinion gear need to be replaced? Thank you!

[GMOG]

Looking at the photo it's easy to see that the rack's teeth do not engage the pinion's teeth with enough depth. That probably means something has worn and now allows a part to move in ways it isn't supposed to. Either the cocking ring has shifted to the left, or the pinion has moved to the right. Both having wear is also a possibility.

I took a close look at your photo. Looking at the cocking ring's LH side, there appears to be a gap between it and the column it rides on. Have a look at this:



This could be due to camera angle. But, if this shutter were on my bench I'd use a plastic spudger or some other non-marking tool to push the cocking ring to the right to see if it moves enough to correct depthing between the rack and pinion teeth. If the ring moves left-right with enough freedom to throw depthing off then there's the bulk of your problem. You could also push-pull on the pinion to see if it has excess side shake.

I must admit that I do not have prior experience with that shutter, so it's not a problem I've encountered. But I know small machinery and that gap stood out to me so I thought I'd mention it.

[BrianShaw]

https://www.photrio.com/forum/thread...repair.167591/

[GMOG]

https://www.photrio.com/forum/thread...repair.167591/

I see. It appears to be well covered over there. Thanks for the heads up!

We'll see if our man ever chimes back in over here.

[BrianShaw]

I’m quite sure that any additional insight is appreciated, though.

[Paul Ron]

are you sure the ring is properly seated? make sure nothing under it is in the way. if its not perfectly seated it will not function properly.

btw was this shutter ever working while you had it?

if you inherited it this way, someone may have swapped parts n its the wrong gear or ring.

have a picture of it without the ring? id like to see the seat?

[Neal Chaves]

Good luck! I had every single part out of a Synchro Compur O and back in again with repair parts (which were once available) shutter blades. All kinds of repairs coud have been done and were at one time when there was factory support. Might consider using those cells on mirorless medium format..

[wgyang]

Thank you for your advice! Just give you an update. I found the plastic ring on the mounting tube is missing by comparing to another working compur shutter. With a new mounting tube installed, the tensiong ring can mesh with the pinion gear.