spring 93 urge arm 70 counterclockwise toward the platter 46 incoming film 95 moves past guide rollers 66 and 67 then past guide rollers 96 97 and 98 film sprocket 99 and around fail safe roller 100 to the film application roller 104 which applies the film to become the outermost layer of the coil of film 48 on the platter 46 fail safe means are provided to sense the continuous running of the film and to detect any break in the film particularly a longitudinal split one embodiment is shown in fig4 8 and 9 where a sensor arm 106 is pivotally mounted at 107 to a microswitch unit 108 and is biased lightly counterclockwise the distal tip 110 of arm 106 continuously senses the existence of the moving film on roller 100 operation of the device is described with reference to fig8 and 9 in fig8 the sensor tip 110 lightly contacts film 112 during operation in fig9 the film 112 is no longer present as would occur in the event of a film break and the sensor tip is biased into a groove 114 formed in the roller 100 this movement in known manner actuates a microswitch in unit 108 thus stopping the projector and other moving parts of the system a second microswitch may be symmetrically disposed to sense the film near the outer edge of roller 100 in an alternative embodiment an all electronic design can be used in fig7 are shown details of construction of the film metering and application roller assembly near the distal end of pivotal arm 70 is journaled a vertical shaft 120 on its upper portion the film application roller 104 is freely journaled about midway of its length shaft.