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Message |
    
Nico
Tinkerer
Username: Nico
Post Number: 15
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2010 - 10:11 am: | 
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Hell! this camera has infinite problems! Each time I fix something, another thing comes out, it is endless!
The thing is, I was shooting the first test roll on this little one when I realized that the shutter was working irregularly at slower speeds than 1/60. I tested it a lot when the roll was out and suddenly the blades got stuck open. Tried to wind again to see what happened, sometimes it closed, sometimes didn't. It jammed more often in 1/8 and B. So I thought it was dirty. I cleaned the thing with lighter fluid and graphite as Henry explains in his repair notes and it closed up, but it was the same: a little bit smoother but continued to get stuck.
Also, I noticed two odd things while testing at different speeds: one, sometimes you could wind twice! that is two full winds, and you could shoot after the first or after the second if you wanted so. Sometimes, the double exp. safety-lock worked fine.
Two, the shutter was half the speed than it should be. I've compared it with my well working Hi-matic 7s and definitely was slow. For example 1/8 on Demi S was more alike 1/4 on the Minolta and so up to 1/60 where you hardly can tell the difference.
Did someone had to suffer this problem with a Demi or another camera? Is there any fix to this? Or the shutter is just crap?
I'm afraid of the possibility of having damaged the winding-charging mechanism while trying to unlock the blades at the beginning, or that all this are symptoms of different problems.
What should I search for? What should I do?
I'm scared...
Thank you very much.
(Sorry for the ugly writing but I wanted to be fast) |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 167
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2010 - 11:28 am: |
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Well, Henry's note is good only if contamination is minimal and concentrated around blades, even then I wouldn't do it his way voluntarily.
Your problem is most likely due to lubricants gumming up. It's common in old cameras. All your problems can be tracked back to this-or-that lever-or-catch not moving easy enough to catch/release things in time with provided spring strengths. Old oils are organic-based and get nasty-sticky with time (and oxygen).
The solution is to clean the mechanics thoroughly, disassembling it first. Flushing without disassembly with lighter fluid only moves gunk around - if you are lucky it gets somewhere where it disturbs less, but most of the time it just sticks back as soon as it's dry.
Marek |
Nico
Tinkerer
Username: Nico
Post Number: 17
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2010 - 05:54 pm: |
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Hi Marek!
So what you are saying is that I have to disassembly the whole shutter mechanism and clean each piece one by one, or just to get off the unit cover and flush-shake will be enough? I'm afraid to touch anything delicate and break it, to lose some spring or something.
Or is it a safe task?
Thank you for the help. |
Aphototaker
Tinkerer
Username: Aphototaker
Post Number: 246
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2010 - 09:21 pm: |
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I faced a similar problem in a Konica S2 Auto. Dunking the shutter mechanism in naphtha for some minutes, taking it out and working the shutter some times, and then dunking it again in naphtha for some more time followed by a few hours of drying worked like a charm.
In another similar camera, this sort of did not work as well as the previous time, I then took out the shutter timing mechanism and repeated the procedure again. The timing mech was dropped in naphtha bath as was the rest of the mechanism. Worked the shutter, as well as the timer, a few times and then let it out to dry for an hour or so. Then this one worked fine as well.
I suppose it depends on how much of the lubricants are present there that are prevented smooth motion of the shutter. If this is real cause in your case, I would say give it some time and effort, but naphtha bath should do the trick.
Good luck. |
Nico
Tinkerer
Username: Nico
Post Number: 21
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 20, 2010 - 11:14 am: |
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Okey, first of all, thank you both for you're advices. I've already immersed the shutter mech in lighter fluid without its cover and rear lens and it worked perfectly, but when it got dry it started to freeze again. I believed it was the gunk reallocated in the blades so I dunked it again a few more times in fresh fluid a couple of hours to make it cleaner. Once again it was very stiff and froze some times, but now the cocking and release lever are very hard to move. Seems that the whole mech is very clean but there is too much friction between pieces, and that is causing the blades to freeze and work slow, not gunk in it. I don't know if this mechanism was designed to work dry or what but I'm sure this is wrong because it wasn't so stiff before. May be someone can point me some lubricant to work with. Any tip will be useful, I don't know how to continue. If you need so, I can post tome images of the mechanism to point which two levers are suffering friction while working.
Thank you again.
Nicolás |
Lrsnrl
Tinkerer
Username: Lrsnrl
Post Number: 3
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 20, 2010 - 11:28 pm: |
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These shutters were made work with very minimal
lubrication. It sounds like your cleaning fluid
is not able to get into some of the very small
spaces and the old lubricant is still creating
a lot of drag. The only way to insure the shutter
mechanism is totally clean is to completely dis-
asseble the mechanism and clean each part indi-
vidually. It appears your Demi S has a Seikosha
shutter and you can find instructions and photos
at Daniel Mitchell's website at pheugo.com.
Use your digital camera a take a picture each
time you remove a screw or part. Put your screws
and parts in small envelopes and label them.
I just got done cleaning a Seikosha SLV that was
completely frozen because of the old lubricants
that had migrated onto the shutter blades and now
it works like a charm. Using any kind of lubri-
cant on a shutter is a recipe for disaster. |
Nico
Tinkerer
Username: Nico
Post Number: 22
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 02, 2010 - 09:49 am: |
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Ok, solved the problem which was, after all, me.
Just an advice for the newbies, NEVER SOAK YOU'RE SHUTTER WITH NAPHTHA IN A PLASTIC POT. Thats what I did and it was the most stupid thing I could do.
Well, the lubricants went away but when the fuild dried out, the disolved plastic soup formed a nasty coating in all the pieces and pivots.
So I had to take apart each piece to clean them individually, so Lrsnrl, you were right, it is the only way sometimes.
It wasn't as tricky as I thought. The mech is pretty simple to understand it's work.
After cleaning throughly, all went okay, except for some friction in some pivots, so I putted a TINY bit of liquid vaseline on a pair of them.
The whole thing works very well now, and the blades work smooth as butter being dry.
However, there is an important problem. All speeds seems to work well to me, but the odd thing is that 1/60 is slower than 1/30, allways.
I double checked the springs, pivot friction, and gears, but I couldn't make any conclusion.
What can be wrong now?
Saving that problem, its all finished.
Thank you |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 150
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 02, 2010 - 01:36 pm: |
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I had a similar situation with a Canonet QL19. I don't know if it is the same shutter, but you can check out this old post.
https://kyp.hauslendale.com/classics/forum/messages/2/16499.html |
Lrsnrl
Tinkerer
Username: Lrsnrl
Post Number: 5
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 02, 2010 - 10:26 pm: |
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How do the other slow speeds seem? Is the 1/60
too slow or the 1/30 too fast?
Some shutter speed governors have two escapements
and are controlles by a peg that fits into a slot
in the shutter speed plate. For the fast shutter
speeds only one escapement is used and for the
slower shutter speeds both escapements are used. |
Nico
Tinkerer
Username: Nico
Post Number: 23
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 02, 2010 - 10:57 pm: |
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Thank you both, Weynemel and Lrsnrl, I checked the pins or escapaments you two mention/posted-in-old-threads, but all seems to be in its place. They are activated/deactivated when they should and they're not bent. The plate and gears work well in slow speeds and in the faster ones, they don't.
The only thing is 1/60 and 1/30 that are very similar, but actually, they seem as they were switched. 1/60 looks like my Hi-Matic's 1/30 and vice versa!
What da'...!
While writing this, I've noticed some wired sound like a squeak when cocking, and a line scratched on the base brass, in one of the main arm's pivot path, the one that stops on the release lever assy. May be that, I could file it. But if its not that... |
Nico
Tinkerer
Username: Nico
Post Number: 24
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 04, 2010 - 11:10 am: |
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Nothing. The squeak is no longer a problem and bent the piece that opens the blades that was stiff, but the 1/30-1/60 switching thing is still there. Any idea? |
Nico
Tinkerer
Username: Nico
Post Number: 25
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 05, 2010 - 10:29 pm: |
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Definitely there is something wrong.T his are my readings of the shutter speeds delivered by my new ex-mouse photo-transistor tester.
setting ms
1/8 .......... 126
1/15 .......... 53
1/30 .......... 9
1/60 .......... 23
1/125 .......... 7
1/250 .......... 6
1/500 .......... 6
So in the end, all seems to be off, 1/30 is as fast as 1/125, then 1/250 and 1/500 are pretty much the same, and so. The only two that are precise enough are 1/8 and 1/125.
I don't know how much precision to expect but all the times seem very random.
What do you think? |
Lrsnrl
Tinkerer
Username: Lrsnrl
Post Number: 7
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 07, 2010 - 10:22 pm: |
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I'm just guessing here but I think your shutter
speed governor has two escapements. For low
speeds a slot in the speed selector ring allows
the low speed escapement to be connected to the
high speed escapement and this slows the whole
thing down. It looks like there is some wear on
your selector ring that is allowing the low speed
escapement to pop out prematurely when it is set
to 1/30 sec. |
Autodiag
Tinkerer
Username: Autodiag
Post Number: 1
Registered: 09-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 14, 2010 - 08:18 pm: |
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em, i think this is really not easy thing to do.
well , i am Bella and most friends have cars, and when your car meet some problems, you must repair it for yourself,so hope the web i introduce to you could help.As all my friends who like it very much.http://www.autodiag.de
so once you come across problem,you could contact me. |
Nico
Tinkerer
Username: Nico
Post Number: 31
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2010 - 09:15 am: |
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Well, thanks Bella but the camera I own is one of those that don't have weels. That wasn't developed yet in de sixties. But thank you for you're offering, best luck next time! |
Nico
Tinkerer
Username: Nico
Post Number: 32
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2010 - 01:49 pm: |
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FINALLY! After a lot of wrestle with this little thing I have it working ALMOST fine (1/30 is the exception). I did what I was avoiding to do: a complete disassembling. Removed the helicoid (the two of them), the rings and retaining plates, and finally wiped throughly the shutter and diaphragm leafs. A lot of plastic had reached there and formed a dull and resistant coating.
Now it really moves and sounds as new.
So all the speeds are +/- 1/3 as they should be, except 1/500, that gives a random number between 3 and 7 ms, what I assume that's because of the changing position of the sensor behind the lens (I move it every time I charge), and 1/30 that insist in behave as a higher set.
I have readings from 5 to 9 ms, as if there were no retard at all, but the odd thing is that the retarder assy IS working and it IS being activated by the pins and all.
I can even interrupt it by placing a toothpick in the retarder metal-dented-sheet-thing that retards the gears and make it advance at will moving it to one side or another.
So it's all functioning but a lot faster than it should. I'm thinking that the speed setting ring that sets the distance or travel of the retarder's pin could be filed in the 1/30 part to force it to have more travel.
Maybe thats too risky and there could be another and less drastic solution.
What do you fellows think?
Come on, this is the last battle!
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Lrsnrl
Tinkerer
Username: Lrsnrl
Post Number: 8
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2010 - 05:24 pm: |
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Looks like you have most of the battle won. If it
worked before and the speed governor is workin as
it should I don't think filing is advisable. What
you take off you can't put back. |
Autodiag
Tinkerer
Username: Autodiag
Post Number: 2
Registered: 09-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2010 - 08:16 pm: |
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I do not know why the problem will be like this.Those days i find a good place www.autodiag.de ,there are many tools for my car repairing,such as BMW INPA ,Lauch X431, Opel com
ect.They are really help me and my friends a lot.
Just right i come here, and remember this to tell them you all. |
Nico
Tinkerer
Username: Nico
Post Number: 33
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 16, 2010 - 11:54 am: |
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Ok, why just me? Go bother someone else! |
Nico
Tinkerer
Username: Nico
Post Number: 34
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 24, 2010 - 03:53 pm: |
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YES! Mission accomplished. It was the speed governor after all. Just when I opened the camera for the first time I noticed one perfect rounded mark above the 1/30 part of the governor, but I thought it was a factory mark or something. After trying every possibility to slow down the shutter action at that speed I've started to suspect. It appeared to be an adjustment done by the factory or some service, ages ago. I think the factory distance for the speed was incorrect so they gave it a heavy and precise smack to extend the metal. Probably, the owners used the camera like this never realizing it had a problem.
I filed it in small amounts and controlled the speed obtained that way until it were something rational.
It came out perfect, and now every setting is around +/- 1/3 its nominal speed.
So summarizing:
The 1/30 setting working at +/- 9ms was the bad speed governor.
The overall slowdown was gunk in the mech and shutter leafs.
It was easy after all.
But a lot time consuming.
I think I'll never do it again, haha! At least for the next 2 years. I'm exhausted of repairing things, I wanna take photos!!
Thanks to all for you're time and kindness! |
