| Author |
Message |
    
Douwe
Tinkerer
Username: Douwe
Post Number: 1
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 17, 2010 - 12:22 pm: | 
|
Hi everybody,
I am repairing the film transport of a mamiya c220 I got from a friend. It seems to me that a spring in the dividing disk is too loose to force the black ring to its proper position relative to the silver ring.
The spring is 2mm long, 1.2mm across, and stretches to 6mm when in use.
Does anybody know where I can find a replacement. I am based in Amsterdam, but the postage isn't going to kill me so anywhere would be fine.
 |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 62
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 17, 2010 - 01:58 pm: |
|
Are you sure that's the problem? From what I can tell from this photo (which is a bit on the small side), the spring looks fine. Doesn't appear to be deformed in any way. Is it possible that perhaps dirt or something sticky is interfering with the rotation of these rings? Just a thought. |
Douwe
Tinkerer
Username: Douwe
Post Number: 2
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 18, 2010 - 01:52 am: |
|
Hi David,
Yes you might be right. I am quite sure at least that the black ring doesn't snap back as fast as it should. Do these springs loose their tension after 25 years?
Alternatively, what would be a auitable lubricant?
Thanks,
Douwe |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 64
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 18, 2010 - 02:38 am: |
|
Since I don't know the exact location or function of these parts, I can only take an educated guess, which would be to use grease since they're part of the film transport mechanism. Others here could probably give a more reliable opinion. But certainly you'd want to clean everything first before applying new lubricant.
And no, springs shouldn't lose tension even after 50 years, unless they've been stretched past their tensile limit, which doesn't appear to have happened here. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 189
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 18, 2010 - 06:54 pm: |
|
The spring looks as good as new.
Try using a dry silicon or graphite lubricant instead of grease. These parts must move freely.
Also check to see if there are any burs or distortions on the edges that may cause it to hang up? |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 65
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 18, 2010 - 07:39 pm: |
|
Agree, but be careful if you choose graphite: it's easy to get it in lenses if you're not careful. The nice thing about graphite is that it's a completely dry lubricant.
I'd still like to hear from an "expert" what the correct lubricant would be to use here. |
Douwe
Tinkerer
Username: Douwe
Post Number: 3
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 19, 2010 - 03:05 am: |
|
Thank you for all the good advice so far. I will try to clean the parts, use some graphite and reassemble. To give a bit more information on the parts and their environment:
both rings are mounted on a single white plastic disk. The black ring moves freely apart from the attached spring, the silver ring is fixed to the white disk on top of the black ring. The black ring should move freely between the plastic and the silver ring. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 191
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 19, 2010 - 03:54 am: |
|
This part is very isolated from the lens since the TLR's workings are inside and sealed in the camera body, not anywhere near the lens.
Besides when putting on graphite, rub it into the part, not splash it around inside the camera. I like the dry silicon spray. It tends to stick where it is intened and doesn't spread once dry. |
Douwe
Tinkerer
Username: Douwe
Post Number: 4
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 19, 2010 - 09:32 am: |
|
Problem solved. Cleaning the surfaces revealed some rough spots that were probably caused by grit trapped in the mechanism. careful sanding, cleaning, and lubricating did the job.
Thanks to all of you for the helpful advice. Back to picture taking for me! |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 193
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 19, 2010 - 01:52 pm: |
|
Those cameras don't die from hard work, they die of lonelyness. A little cleaning and they are as good as new. |
