    
David
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 28, 2004 - 07:52 pm: | 
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Hi there,
I hope there is someone out there who knows about how to reassemble the timing gears on the Pentax SV SLR camera.
I picked up an old one from the secondhand store which had the shutter jammed open, the shutter release jammed in the "up" position so that you could not get it to realse, and the "return" button on the base also jammed in. Taking my chances, I attempted to see what was wrong with the unit, since I assumed that there could be nothing major due to the well looked after state that it is in.
It turned out that the fault was some dried up lubricant on one of the gears that prevented an arm from being pushed right around. On solving that, the camera worked fine, just like new.
Seeing how dirty it was inside - all the gears being caked with dust and debris, I decided to disassemble the parts on the top on the speed dial side. This would enable me to fully clean and relubricate all the parts to a like-new condition.
This being my first time at disassembling a mechnaical SLR camera, I came about the timing gears.
Unaware of the timing and the tension in the shutter, I disassembled the gears, and am now facing the impossible task of reaseembling just thes 3 or so gears.
You have the 2 brass gears stacked one on top of the other locked together with a copper key. The top one meshes with the shutter gears and the lower one meshes with the winding gears. When the pressing release, the copper key is pushed down disengaging the 2 gears, enabling the shutter to run off freely.
The closest I have come to getting it back to working is by first releasing the tension in both the curtains. Now that I have the no tension on the shutters, I advanced them manually by turning the gears, as if it was in the cocked position. I then turned the winding gear manually into the positon that it would be in if it was cocked. I then placed the back the the steel gear (This is the one where you adjust the speed since the speed dial is assembled on top of this) so that it was in the positon where the indicator would show that it was cocked. Next, I meshed in the lower brass gear so that the slot in the gear matched the slot so that the copper key could be disengaged, and fitted back the top gear with the slots matching. Next I increased the tension back on both curtains by adjusting the ratcheting gears on the bottom of the unit.
The state that the camera is in now would technically be that if it was cocked. I press the release button and away goes the shutter as planned, however, the shutter fails to close fully at the end. This is OK since the tension on the cutains might not be enough and can be adjusted later.
This is where the real problem starts. The 2 brass gears stacked on top of the other are meant to come back to the original positons so that shutter can be re-cocked. This is not so and is always off by like 3 or 4 teeth. Since this is off, the copper key cannot fully rise out of the slot in the hub beneath, preventing the winding gears from recocking the shutter. By manually aligning the slot of the top brass gear, the shutter can now be recocked. On recocking, the two curtains have a small gap between the 2. This should not be the case; the 2 should be fully closed to prevent light entering. When the winding gears are wound to the state that the shutter is fully closed (ie. fully to the right looking from the back of the camera), the winding gear is not in positon as if it was cocked, and therefore, thus the copper key is not in the position over the slot in the hub - and so cannot be released.
How do you go about setting up the timing gears ??? There must be a way of setting the timing - since the brass gears oftne need replacing due to them becoming stripped.
Thank you for your time and efforts in advance
Regards
David |
