snychro-compur DIY cleanup woes

[mikec]

Question for the shutter experts:

I have recently bought a used 75mm f8 Schneider SA in a Linhof synchro-compur 0 and found that the low shutter speeds were very slow, the 1sec completely sticking. Looking around this and other forums I have seen that flushing any gunge is usually all that is needed to fix this. So I decided to take the plunge and started by inspecting for possible damage.
After removing the retaining ring, shutter speed ring ,facia plate and the shutter speed cam plate, I could see what appeared to be a liberal quantity of graphite grease applied to the main spring and that some had migrated onto the surrounding surfaces. As I had not read any reference to the use of such grease I thought it a possible source of a problem. I therefor removed the cocking rack and took out the timing gear set to give it a bath in lighter fluid and cleaned up the mainspring without removing it. I also put a little solvent on all the other pivots and then reassembled.
problem 1
When putting back the timing gear set I found that the shutter could not be cocked. This turned out to be due to the tip of the timing gear block preventing the mainspring gear plate from turning. On looking at the timing gear I noticed that the pin which engages in the speed cam plate was at the deapest point in its slot but remembered that before unscrewing the unit it had been a little up the slope. After removing the unit again I could see that by pushing the pin up the slope I could move the part that had blocked the main spring. So, thinking that I had solve the issue I slid the pin back up the slope while reinserting and screwing down the unit. Now I could see that the main spring gear was free and I could tension the shutter ( I did not do this fully while disassembled as the cocking leaver return spring pops off its post rather easily). I reassembled everthing and tested the shutter.
problem 2
The 1s, 1/2s and 1/4s speeds are now correct, but the 1/8, and 1/15 appear to fire at about 1/125s. 1/30 to 1/500 seem OK.
So I disassembled it again and when I excersized the speed cam plate without the ring being present and I could see that speed selection pin which follows the cam, was not following into the deeper cam recesses. This is due to the fact that adjustment I had had to make above, had prevented the pin getting to the base of the slope on the timing gear set top plate. grrrrrr!!!! Needless to say I tried to rebuild, but with the same result.
I am sure there is a simple solution to this as the only piece I removed, was the entire timing gear set which is held by just two screws with no possibility of adjustment I can see.
Does anyone who has pulled these apart know the answer, or should I pack it off to one of the experts?

[BrianShaw]

I, too, am an ameteur shutter repair-person. Here are several observations based on what you write:

1. You picked one of the more finicky shutters to start with. Synchro-Compur has lots of little springs that tend to pop and are difficult to get back in plae... especially if one didn't notice where they came from before they popped. The manual, available from a number of internet sellers, provides details of spring locations.

2. Sychro-Compur shutters are not one of those shutters that run well "dry", nor were they intended to be run dry. The manual, available from a number of internet sellers, provides details of which lubes to use in various parts of the shutter.

3. Taking the shutter speed gear train out affected the shutter speeds. There is one screw with a larger hole. This provides a way to pivot the gear train around the other screw to adjust the 1 sec. speed. All other speeds are controlled by the slot in the timing plate. Adjusting them requires adjusting the slot... so they "are what they are" and they'll "be what they were" if you got the 1-sec adjusted correctly. The manual, available from a number of internet sellers, provides details of the timing adjustment procedure.

4. Replacing the speed plate and the retaining ring is often a challenge if the various pins are not positioned correctly. The ring will bind, as it sounds like you found out. Also, tightening the retaining ring too much or too little will cause the shutter to not work properly. The manual, available from a number of internet sellers, provides details of how the pins are arranged in the speed ring.

5. I give you credit for trying... and if you got that far I think you'll be successful if you keep at it. But as you might imply from my comments, above, having the manual is a major benefit. Unless you've lost parts, consider getting a manual and trying it again.

Good luck!

p.s. If you are skilled at Google-ing you might actually find some useful infor ont he net. I never found the complete repair manual, but found this:

http://www.rolandandcaroline.co.uk/synchro-compur.html

[mikec]

thanks for that Brian, I did find an exploded drawing where some adjustment of the timing gear train is indicated and your description of pivoting the gear train round the larger screw axis helps explain what the drawing was showing. I'll try that and post the result. BTW I was trying to insert pics to better explain my issue, but it seems I need a url (ie a web site) to reference them. Is that so? or is there an easier way?

[Colin Graham]

Small world. I just spent ten hours repairing a compur rapid with parts from a synchro compur p. I wish I'd checked in here first. They really should put a little sticker saying contents under pressure on these things...I never realized there could be so many possible permutations of cam, spring, and lever. And now I'm out of whiskey and expletives

[mikec]

tried some adjustment as suggested. no luck. there is some play, but not enough to make any diffrence to the outcome. I am obviously not doing it correctly. I'll have to find a pic of what it should look like when remounted correctly. The penny will probably drop then. Next time I'll take some photos BEFORE I take something to bits.

[BrianShaw]

And now I'm out of whiskey and expletives

That happened to me too on the first Sychro-Compur I took apart! Fortunately I found a local store where I could buy more whisky and learn a few expletives I never before heard.

[BrianShaw]

Next time I'll take some photos BEFORE I take something to bits.

No matter what, you'll always find a shadow right where you need to see a detail... trust me. What's worse, Mike... you never got down to the "bits" level. You removed an 'assembly'. It gets worse the more things you take out and take apart.

Usually I'm not this nice , but today is Sunday so I'm on my best behavior:

http://search.ebay.com/search/search...air&category0=

Other alternatives:

- I'll buy that old broken shutter and lens from you... if the price is right

- http://www.flutotscamerarepair.com/ I haven't used her but a friend has had several shutters overhauled by Carol and is really, really happy with her skills and service. There are a number of threads hear and on other forums that sing her praises. About $50.

[Bob Gentile]

"... a friend has had several shutters overhauled by Carol and is really, really happy with her skills and service. There are a number of threads hear and on other forums that sing her praises..."

Without trying to turn this into yet another of those threads which sing her praises, she's very competent, very fast, very reasonable, and very nice! A great human being.