Posted by Dongyun Hao on January 11, 2001 at 18:58:46:
In Reply to: Polariod back for Century Graphic (6x9) posted by John Blackford on January 10, 2001 at 10:01:25:Hi, John and Dennis
This is just about the question whose answer I am seeking for too. I have both the Century and Horseman gears. Although the 'graflrx.org' documents that other makers' rollbacks can fit on the Graflex's Graflok, I found vertually this is not true for the two Centurys that I have, an all-black one and a red-bellow model.
This is mainly because the Graflok's metal slider has a right-angle bended 'handle' at the both ends which does not enable the Horseman back (and also the Polaroid BK) to engage the right position into the Graflok leaving virtually the back unlocked. Whilst, Horseman adopted the original Graflok design with a little modification making the 'handle' (only one, not two like Graflok) position at the middle of the slider bar. Thus, there would be no interference btwn BK and the Lock. I added to my Century's Graflok one more thin metal washer under each of the slider-fixing screw nuts to lift up a little the slider. This has successfully (with the handle virtually touched to the back though, when locking) made the Horseman rollback locked into the red-bellow Century, but this doses not work for the all-back Century and the Horseman Polaroid back. It is apparent that the QC level in that era was not so high.
The other difference I observed is that the protruding depth of the back-body interface btwn the Century back and the modern Horseman back is slightly different. I have no Graflex back of any kind, I worked out this by measuring the lock house of my Cneturys. My measurement (not bigger than 0.05mm error) shows about 0.2 to 0.25mm. Not so big, but enough to make them not inter-usable. I believe others may have noticed this before and various resolutions should have been proposed. I am interested in how Dennis did his work. Personally, replayment of the Graflok slider lock bar with a Horseman type (central handled) should permenantly solve the problem (I suppose to hand-make one myself). But, what about the above-mentioned 0.2 to 0.25mm difference. Since the ground glass back does not reply on the Graflok, what about the possible problem caused by the different btwn the film plan and focussing plan? I would appreciate all kinds of relating answers. Thanks very much!
Dongyun