The bit about slitting the film and then hanging it off a door frame to gauge 580 mm, seems to me frought with danger. I wonder if it could be possible to slit half a roll of film in your slitter and then cut it out. Could it work by counting the cranks?
That's a good idea!
I tried it out straight away. I need exactly 14.5 turns with the crank in the slitter to pull 600 mm of Kodak Ektar 100 into the empty cartridge. But because the first 45 mm are exposed to light when inserted into the slitter, I have to add another 1.5 turns. So 16 turns in total.
When you then open the slitter, you cut off the slit film just before the take-up cartridge. Then remove the take-up cartridge. This is all done in the light.
The procedure should then be as follows:
In the dark, all you have to do is pull out the film completely and cut off 45 mm (two fingers wide?) in front of the cartridge. Then you have two Minox films of approx. 600 mm and the two perforated edge strips in your hand.
I'll give it a try and report back.
This actually seems to me to be much easier than my previous method, because you cut the film to length in the light. In addition, you still have half an unslit KB film in the original cartridge, with which you can do other things.
You can also determine the number of revolutions yourself without the slitter, because the number of revolutions only depends on the spool diameter of the cartridge and the film thickness. I have measured a diameter of 10.8 mm. I hope that all KB cartridges have this spool diameter. Perhaps someone could confirm this?
I measured a thickness of 0.16 mm for the Kodak Ektar 100. The Kodak Portra 400, the Kodak Gold 200 and the CineSill 50d have the same thickness. The ADOX CMS 20 is thinner at 0.11 mm. I therefore needed 15 + 1.5 turns with it for 600 mm. These are the films I have on hand. Since most of the films I use (except the ADOX) have the same thickness, the revolutions are the same. And even with this thin film, it only makes half a turn.
