Movie showing transport system working

This little movie shows the white leader film being pulled along by the pin, which is probably impossible to see. Using a spring, the pin rises up into a sprocket hole when the solenoid is not fired. Firing the solenoid lowers the pin so that the pin assembly can move backwards without dragging the film back with it. This cycle ultimately will drag an entire reel of film over my scanner bed. The copper tab presses the film down so the pin can reach through the plane of the film. (Since there is too much slop in my improvised film rails built from windshield wiper blade spines.) When the metal pins touches the copper I will read this as "pin engaged" through the parallel port and that would mean that it is okay to start advancing the film. Otherwise, the pin might be stuck when it hits the film where there is no sprocket hole. By determining whether the pin is "engaged" I can ascertain a start position (call it zero) so that by using the stepper steps I can precisely advance the film a known distance (eg., 500 steps distant from the zero position.) Then I can back up the film a few steps if need be. The metal parts are mainly Erector set parts that had lying around the house. Erector sets are perfect for prototyping robots. The pin assembly is attached to the metal bed where there was once a scanner assembly. As I built this I was wondering if the motor could really pull a strip of film along, and it can. But if the film hangs up, the entire bed gets pulled upwards as it tries to drag the stuck film. The film was only hanging here because I didn't have a spacer to keep the scanner lid fully away from the film. I guess it is time to add a take-up reel!

Here is the url of the movie, posted to photobucket:

http://smg.photobucket.com/albums/v241/pixhopwow/?action=view&current=MOV07480.flv