| Author | Message | ||
     Zenzaman Tinkerer Username: Zenzaman Post Number: 6 Registered: 11-2010 Rating: N/A |
gear-corded i guess  ) there is in fact a kind of 'clutch' mechanism. i finally got the way it works, by determining that the cord control disc only pulls the cord when both sensing rings are in place. i hope my explanation is clear enough... http://i187.photobucket.com/albums/x228/alinCiortea/camera%20repair/IMG_3557_3.j pg this image shows the gear '6' removed from the cord control disc. my explanation implies that it's put back together. the aperture sensing ring engages the gear '6'. the shutter speed sensing ring engages the removable gear 1. the cord control disc assembly is made of a geared disc beneath the visibile '4' disc. this '4' disc has a helicoidal slit across its circumference that hosts the cord. if the gear '5' is free, turning the gear '1' (by turning the aperture sensing ring) will spin all the gears EXCEPT for the disc '4'. when the shutter speed sensing ring is turned, the aperture sensing ring is still and therefore will not allow movement of gear '6', that in turn will block gear '5'. by imobilizing this gear, the movement of the shutter speed sensing ring will cause the movement of disc '4' and therefore it will pull the cord that acts upon the galvanometer. i don't fully understand the relationship between the gear '5', the disc '4' and the geared disc beneath disc '4'. i presume the discs share the same axel but are not connected directly. as the gear '5' seems nitted in place and the disc '4' has a slotted ring that keeps it in place that i couldn't remove (it has barely visible slots that i don't really wanna ruin), i can't investigate further (and anyway, it is of less importance right now). what's obvious now is that the 'idle' position of disc '4' dictates the correct exposure for a given shutter speed (with the rest of the variables known), in this case 1/1000s (required for the correct reassembly of the shutter sensing ring in respect to the shutter speed gears beneath the mirror). unfortunately there are no marks on disc '4', except for the place where the cord is glued in place. the problem is that i don't know where to align that mark. i thought perhaps it should point to 6 o'clock but the tensioning seems too low to compensate for the error i believe it has now. next option would be 3 o'clock but it might as well be any other value. perhaps someone has some knowledge about it? |