Help! Retina llc spring connection

[Kevcaster]

Hello
I am servicing a Retina llc with a Synchro Compur shutter, 1954.
I removed the front speed cam plate and out jumped the cocking rack and related gear - see the pictures. I have looked for advice on various sites but cannot seem to locate the model of shutter that I am working on.

I am hoping some of you who have travelled this path can advise me on the re-fitment and orientation of these items. All help gratefully received.
Here is the main assembly showing the cocking rack set to one side and the spring seated on it's pillar. It appears that the lower spur of the spring locates in the star lever on which it resides.

Synchro compur rack assembly by knjy, on Flickr

Here are the two items I need to re-fit and mate with the cocking rack

Rack and spring for synchro compur by knjy, on Flickr

The spring is a compression spring with a short tab and a longer tab at 90 degrees to each other and on opposite ends.
All help gratefully received.
Kevin

 

[Grytpype]

For the picture from the Compur manual click this link.

Hope this helps,

Steve.

 

[farlymac]

The long tang of the spring goes into a slot opposite of where your purple arrow is pointing. It looks to me that the other tang that would reside against the drive is broken off (I see a piece of it just above the point of your purple arrow, laying on the shutter housing floor). You need a replacement spring.

PF

 

[colyn]

For a replacement spring I'd contact Chris at http://retinarescue.com/ to see if he has a spare he'll sell you..

 

[Kevcaster]

Hi all many thanks for such quick responses. The tang is intact, the picture is misleading, and I checked the very useful pages in the above link. They show the exploded view which helped to identify the orientation.
What puzzles me is that there is no tension in the shutter when wound the cocking plate moves as it should and seems to capture all the parts on it's journey, and when released is almost passive, the blades not opening and no oomph. The spring shown appears to be under very little tension and yet it is the biggest spring in this whole mechanism. I am wondering if it is to be pre-loaded? If so how is this achieved?
Also in this model there is no big heavy 1/500th spring, so what delivers the fast speeds?
You will have guessed I am unskilled in Compurs so hope for some advice. I can service focal plane shutters etc.
Kevin

 

[Gumby]

I've walked that road several times. You picked one of the more difficult shutters to service. Let me give you several suggestions:

1. That spring does not normally "jump out". Slow down and review the manual before doing anything else. If you proceed to poke, prod, and pull there are other springs that will "jump out" and you'll be in even worse shape than you are currently.
2. Review the manual, and then review it again before proceeding. The manual is full of very good information that you NEED TO KNOW b-e-f-o-r-e you start stripping down the shutter for servicing.
3. Remove the shutter from the camera. You really can't service the shutter very easily or effectively while it is still on the camera.
4. After you have cleaned the shutter components and before you reassemble the parts, review the manual, especially the lubrication plan.
5. As you reassemble, have handy a copy of the spring diagram. There is one in particular that is not intuitive and when (not if) you don't get it properly replaced will cause yoru shutter to not function... and will cause you to get frustrated... and incite a barrage of curse words... and will bring you to the brink of tears.

 

[Kevcaster]

Ed wise words indeed.
My life is strewn with projects that attract the phrase "this is one of the more difficult ......"
This includes my house.
I am busy finding a manual to review and will take your advice. So far I have simply flushed it through and ultrasonically cleaned the two escapements fearful to go further. So a good place to take a break.
Thanks for taking the time to share a bit of wisdom
Kevin

 

[Gumby]

Please read your PMs, Kevin.

 

[mikemc_photo]

The long tang of the spring goes into a slot opposite of where your purple arrow is pointing. It looks to me that the other tang that would reside against the drive is broken off (I see a piece of it just above the point of your purple arrow, laying on the shutter housing floor). You need a replacement spring.

PF

Long end goes into the slot in this silver part, The "stub" fits into the hole on the main drive cam.

Top speed on this shutter is controlled by the mainspring, no helper spring like the Compur Rapid. The M/S looks worn, and if so 1/500th is slow, assuming the shutter and escapement is clean and lubricated

In the compur picture, note the tab on the M/S....its facing down, look for the hole below, then you will have to tension this spring, wind with tweezers and insert into the slot

 

[Kevcaster]

Long end goes into the slot in this silver part, The "stub" fits into the hole on the main drive cam.

In the compur picture, note the tab on the M/S....its facing down, look for the hole below, then you will have to tension this spring, wind with tweezers and insert into the slot

Thanks for your response. I am not sure which 'slot' this should be fitted into or how it lies when properly fitted. I understand the main drive cam is the three prong item that sits on the post. The spring stub locates in a hole at the base of this. The tang then has to be located somewhere and this spring tensioned in some way - this is the mystery at the moment.
For example: Does the spring locate on the bent stub of the half-gear?
Slow progress by me on this despite all your help!
Kevin

 

[Kevcaster]

OK Mikemc got it, my stupidity. I understand what you were saying and managed to slot the spring tang into its stop.
Many thanks .
Kevin

 

[Kevcaster]

All done and feels good, shutter now fires on all settings, elf timer works as it should.
Bit of a learning curve this and one which I may not repeat but good to understand about these leaf shutters and the kind of design quality that was put into them. Still impressive after 60 years.
Thanks again for all the help provided
Kevin

 

[mikemc_photo]

It really is easy, once you have done it!
This shutter is very solid and workable. The flash sync section is tricky, but logical. Glad it works now.