We make similar items all the time. If making only a couple, use a
tapered endmill and do some drawing and calculation first to try and get
an idea of the proper taper and tooth size. After milling on an arbor
(or chuck if the shoulders give you room to grip and keep it true), you
can use a wire brush or similar on a grinder to abrasive machine the
teeth to a more curved profile so they will release properly. Finally,
do your best to polish the tooth faces so that they will not abrade the
film.

There are better ways to get the proper tooth profile but probably not
worth the hassle unless you want to do it as a "learning" project

Koz

Richard J Kinch wrote:

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

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

That item is a stack of several cylindrical components, with the toothed
portion apparently a slice out of a long toothed stock piece, somewhat like
the sprocket stock you can get to make gearbelt pulleys. Would this
toothed stock just be cut from round stock using axial cuts from a custom
bit, incremented with a spin indexer?

I also have an interesting specimen, a 4-inch diameter metal sprocket that
appears to be an exquisitely fine cast version. Is that possible?