"Jeff Wisnia" wrote in message
...
Richard J Kinch wrote:

How does one machine a toothed wheel for a film sprocket such as this:

http://www.lavezzi.com/product272.html

A short, curious story that relates to this: Back around 1969, Life
magazine's photo department bought about one or two hundred thousand (no
exaggeration) indexed, glass-window plastic slide holders. The relationship
of the sprocket holes to the frame area was fixed; there was a single prong
on the molded slide holders that engaged one sprocket hole, and getting the
full frame in the window depended on the camera having a uniform
relationship between the sprocket drive and the window. Besides having a
*uniform* relationship, it needed a *matching* relationship, one that
matched the relationship in the slides.

No one thought much about this until they discovered that the
department-issue Nikons all had different sprocket-hole relationships. g
They were uniform, but each one was different, and practically none of them
had the *same* relationship. Apparently the sprocket drives on Nikon F's
weren't set in any particular relationship to the gears.

Anyway, they tried to take the slide holders back but it was no-go. Nikon
couldn't, or wouldn't, supply the sprockets that they wanted. So they had
Marty Forscher (Professional Camera Repair, then on 42nd Street) machine new
sprocket wheels for all of their Nikons.

It cost them a significant bundle. I think somebody lost a job over it. g

Ed Huntress