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Tjommy
Tinkerer
Username: Tjommy
Post Number: 7
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 18, 2009 - 01:10 pm: | 
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My Olympus 35 RC begins to tear perforation of the film after 30-31 frame...already with 3 different films. What can be the reason? Is the reason in clamping mechanism on the door? or somthing else? |
Glenn
Tinkerer
Username: Glenn
Post Number: 580
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 18, 2009 - 01:48 pm: |
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My guess would be a problem with the take-up spool. The film is not being wound tightly enough around the spool, so at frames 30/31 the space between spool and body is jam packed with coils of film - as the film cannot advance anymore, the perforations tear.
l |
Tjommy
Tinkerer
Username: Tjommy
Post Number: 8
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 18, 2009 - 02:33 pm: |
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Glenn, I ve checked the spool. Nothing seems to be broken or inconsistent. It is clear from dust or film pieces... |
Olympfix
Tinkerer
Username: Olympfix
Post Number: 9
Registered: 05-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 18, 2009 - 04:35 pm: |
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You may have the pressure plate 180 degrees out. easy to change. Try that. |
Glenn
Tinkerer
Username: Glenn
Post Number: 582
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 18, 2009 - 06:07 pm: |
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I doubt that the pressure plate is the problem - if it were out of place, all frames would be damaged.
I would get a cheap film and run it through the camera, from frame 25 onwards open the back after each wind on and examine how the film is actually loading onto the take-up spool. Also make sure there is free space for the film to go into around the spool. You should also check that the cassette/rewind knob are free and not miss-placed when you open up the camera each time; however, I cannot think of any reason why the cassette/re-wind knob should routinely jam after 30/31 frames. |
Sevo
Tinkerer
Username: Sevo
Post Number: 41
Registered: 09-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 19, 2009 - 01:58 am: |
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Almost all 35mm film transports work by way of a sprocket wheel that does the actual transport and a take-up spool which merely stores the film without slack, and is friction coupled to the drive train to make up for the variation in diameter across the film length.
The right amount of friction is neccessary for even transport. Too much slip will build up slack in the film chamber so that the sprocket wheel eventually can't push the film forward any more. Excess friction, on the other hand, may pull the film across the sprocket wheel.
In either case, the perforation will tear - so you'll have to work out whether it is by jamming or pulling. Personally I consider the former more likely, as pulling strain will usually already strike at early frame numbers, but YMMV.
Sevo |
Glenn
Tinkerer
Username: Glenn
Post Number: 583
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 19, 2009 - 05:09 am: |
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Hence the need, as I have already stated, to actually observe the state of the film on and around the take-up spool.
A bit of useless information:- Some film stock is more flexible than others, hence this problem sometimes 'suddenly' rearing its head when one changes film type/manufacturer. The camera appears OK with more flexible stock, but jams when the stiffer stocked film is loaded.
Actually the simplest answer is to only load 20 exposure cassettes. I have a number of cameras that are so worn on the take-up spool/shaft bearing surfaces, that this is the only recourse if I want to use them. They are just not worth the effort of replacing/repairing the components; however, they are cosmetically very good and look nice on the shelf. I have better things to do with my time than return equipment, I am not likely to use, back to factory fresh spec. |
Tjommy
Tinkerer
Username: Tjommy
Post Number: 10
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 26, 2009 - 06:29 am: |
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Finally checked with the open back cover- It doesn't tear the perforation... But with the closed back it continiues to tear... |
Sevo
Tinkerer
Username: Sevo
Post Number: 43
Registered: 09-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 26, 2009 - 08:14 am: |
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IIRC the pressure plate in the back has a ridge that holds the film in the sprockets - you'll have to imitate its action in some way to see what is going on.
Sevo |
Glenn
Tinkerer
Username: Glenn
Post Number: 591
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 26, 2009 - 06:16 pm: |
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Taking Olympfix and Sevo's information on board - check the position of the pressure plate. Although with your original comment of tearing only after frames 30/31, I find it hard to imagine that pressure plate is wrongly orientated. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 105
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 27, 2009 - 02:11 am: |
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THe pressure plate only works one way with the 35RC as far as I remember. It has a cutout for the film transport wheel. I think the wheel would not move at all if the pressure plate is installed the other way round. So I guess when it starts tearing the film when closed only indicates that there is not enough room for the film in the taking chamber.
Using 24 frames film would be a work-around. |
