Just a thought.....
One problem with hole positioning on a Nipkow is the angular position.
(11 1/4 degree for 32 hole disc and 12 degree for 30 hole disc etc. ) Errors here leading to crooked horizontal lines in the monitor.
The most accurate way to get these angles is by use of an enginneers indexing head set up on a milling machine table. Most do not possess
such facilities.
BUT, say one had a large old clock movement and the hour hand axis was fixed to the centre of the Nipkow.
By moving the minute hand through 22.5 minutes each time then 32 hole spacing would be achieved. So minute movement would be...
0/22.5/45/7.5 past next hour/30/52.5 and so on.
For a 30 hole disc it would be every 24 minutes. For 60 holes 12 minutes
and so on.
One would have to be careful to keep the axis tight against the gearing to avoid backlash.
If no clock movement available, then a 12/1 set of 2 gears might suffice
using an large old clock face.
The above together with either a radial lead screw or vernier would achieve hole positioning.
As I said, just a thought. Maybe someone can suggest further improvements.
Albert.