RDD658XV - the problem with cutting to a specific lenght and the inability to scan the sides of the material with a camera

The machine has difficulty maintaining the correct sheet size when cutting material unwound from a roll. Lenght differences vary by +/- 5 mm.

I think the solution to this problem would be to scan the edges with a camera and cut the sheet based on that, but unfortunatly I don't have that option anywhere.

Machine - RDD658XV

Camera - JNC

Programs - VCutWorks2.0

I would be very garteful for any help.