Synchro Compur Shutter DIY Question

[Jglavin]

Hi all, could use a little help here.

Long story short, got a good deal on a 135 mm Symmar lens attached to a Synchro-Compur shutter (#051-24). Out of the box fast speeds all worked well, but at slow speeds the shutter would stick open and would require gentle to get it to close. I have repaired small things in the past so I decided to give it a go after scouring for repair guides and videos. I opened the shutter, removed the cam ring, cocking ring and got the escapement out, gave it a clean, lubed it up with watch oil and replaced all the parts. So far so good. Once reassembled fast speeds worked as usual, but now the slow speeds all seemed to fire fast too. Upon reinspection it seems like the pallet arm that controls the slower speeds doesn't want to follow the groves in its cam. It has no tension pushing it towards the inside of the shutter housing. When I cock it to a 1s position and place some gentle pressure on the pallet I can get the slow speed mechanism to work. I'm a bit stumped (having taken it apart and put it back together a half dozen times). I've read that some escapements need to have a spring set to a particular diameter to get the pallet to work, but that doesn't seem to be the case here. It also doesn't seem like the coverplate has any protrusions that interact with the pallet arm. I'm a bit at a loss but I feel like I'm so very close to getting the damned thing to work. Any advice would be amazingly appreciated. Some pictures for context:

 

[retina_restoration]

About replacing the retard gear train: with these shutters, there is usually a specific way to seat the gear train when reassembling that involves making sure the moving arm on the end opposite the post that engages the cam ring, is swung out when positioning it, so that it properly engages the tab on the aperture actuating ring it comes in contact with. (This is very difficult to explain without showing you) If you do not swing that arm out when seating the gear train, then the whole gear train isn't engaging correctly.

Next, when placing the cam plate on top of the assembled shutter, you must turn it back and forth a bit to make sure the engagement post on the gear train is free to engage the cam surfaces. It's very easy to just put the plate down and trap the post underneath it, rather than get it properly positioned to ride the surfaces of the cam plate. I'm assuming you've done that part correctly, so my guess is that the gear train is not seated correctly, preventing the post from freely interacting with the cam plate.

There will be no need to futz with springs on the escapement in this instance.

 

[Jglavin]

Update, it was a blasted little spring that wasn't seated. It must have gotten knocked off when I cleaned it. I hate springs. But now, onto the second step: getting accurate timing!

 

[BrianShaw]

Whatever you do, follow the lubrication schedule in the shutter overhaul document. That will make life a lot easier for you as you get it back in time with the slow speed escapement.

 

[F4U]

I've worked on my share of shutters and just about every other mechsnicsl device you can imagine. So I should be qualified to work on a Synchro Compur? Wrong-o. Highly not recommended. If you back out of the project and button it up with no harm done, be glad. Send it to a profressonal.

 

[grain elevator]

I've worked on my share of shutters and just about every other mechsnicsl device you can imagine. So I should be qualified to work on a Synchro Compur? Wrong-o. Highly not recommended. If you back out of the project and button it up with no harm done, be glad. Send it to a profressonal.

Taking it further apart would be inadvisable, I agree, but as far as the OP went in, I have been (and a little deeper). Both the OP and I have managed to get things back to together and working.

 

[Dan Daniel]

Update, it was a blasted little spring that wasn't seated. It must have gotten knocked off when I cleaned it. I hate springs. But now, onto the second step: getting accurate timing!

Yep! There's also one at the other end that will come off every now and then. It can end up spinning and being far out of position, but you just push it back and relatch it. It repositions itself nicely.

Basic timing procedure- 1, rotate left end (counterclockwise) in or out to get 1 second (speed cam at 1 second). 2, bend pin back and forth to get 1/15 (gentle!!)(speed cam at 1/15). 3, look at small pin at left/countereclockwise end when moving to 1/500. It should move a bit but if set too far you can't rotate speed cam all the way. Again, gentle on the bending.

 

[Jglavin]

I've worked on my share of shutters and just about every other mechsnicsl device you can imagine. So I should be qualified to work on a Synchro Compur? Wrong-o. Highly not recommended. If you back out of the project and button it up with no harm done, be glad. Send it to a profressonal.

I get this. But I got the lens and shutter for $50, and it's not the only one I have in my rotation. A decent CLA would be at least $200 and a few weeks. A new Compur shutter in good working condition would be almost as much. I figured, worse comes to worse it would be a learning experience, given that I only needed to buy a few extra tools and oils. Add to that, as time marches on (and I slowly add to my lens hoard), I figure it's a good skill set to develop and I'm glad to say that it's working and (almost) in time. I agree, though, that if it was a prized shutter or your only one then it's not a good candidate for amateur hour.

Basic timing procedure- 1, rotate left end (counterclockwise) in or out to get 1 second (speed cam at 1 second).

Dan, do you mean to rotate the escapement (nudging it a little bit) or the cam wheel?

Thanks all!

 

[retina_restoration]

I've serviced hundreds of various Compur shutters. Message me if you want one-on-one assistance.

 

[Dan Daniel]

Escapement. It will rotate around the screw on the right end and move in and out with the left end screw loose. I always forget it going in makes it faster or slower but it makes itself clear quickly. The pin is what sits against the speed cam when cocked. For 1/15, uncocked, it should be just ever so slightly off of the cam. Smooth needle nose pliers coming down and ever so slight pressure will change 1/15 timing. Pretty much everything else will fall into place, with maybe adjustment for 1/500 to clear the escapement out of the path of main spring mechanism spinning.