Film-Tech Forum ARCHIVE: Horizontal Scratch Problem

This is topic Horizontal Scratch Problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Darren Ward (Member # 4394) on 06-22-2009, 11:34 PM:

Hi. I've got an issue with a Kinoton FP25, we're getting several small horizontal intermittent scratches across the middle quarter of the screen, there are several on screen at any given point in time in varying places within the area I mentioned. It doesn't happen to every print running on this machine and I'm starting to doubt it's a lacing stuff-up, as everyone is experiencing that wonderful paranoia that comes with triple-checking your lacing after a period of unexplained scratching! If anyone is familiar with this type of scratching, I'd be grateful for some feedback. Thanks.

Posted by Monte L Fullmer (Member # 2797) on 06-22-2009, 11:46 PM:

What about your platter - have we included that unit in the loop for your search .. for laterals are more prone to come from the platter than the projector.

..and usually a roller that isn't square with the film path will do numbers on doing laterals...and this includes any guidance rollers where the film have to travel on.

..and film builds can do these as well if the operator isn't careful enough....

Good luck - Monte

Posted by Darren Ward (Member # 4394) on 06-23-2009, 02:29 AM:

Thanks Monte!

Posted by Michael Schaffer (Member # 1204) on 06-23-2009, 03:09 PM:

quote: Monte L Fullmer
What about your platter

An FP25 doesn't have a platter. It is a system with a spool tower integrated in the column.

That said, the described scratches can happen when the loop under the intermittent sprocket is too big and the film hits the bottom of the shutter housing. That can also happen when the loop is originally OK but the film is misframed - when the projectionist then corrects the framing down (up on the screen), the loop also gets bigger, sometimes to the point when it hits the shutter housing.

Posted by Mark Gulbrandsen (Member # 72) on 06-23-2009, 03:40 PM:

quote: Michael Schaffer
the loop also gets bigger, sometimes to the point when it hits the shutter housing.

Ha...LOLOLOL... Just like the Ballantyne does except on the Ballantyne you hit the two screws holding the stripper in place then you scratch the bajesus out of the film.

Mark

Posted by Brad Miller (Member # 2) on 06-23-2009, 06:02 PM:

quote: Michael Schaffer
That can also happen when the loop is originally OK but the film is misframed - when the projectionist then corrects the framing down (up on the screen), the loop also gets bigger, sometimes to the point when it hits the shutter housing.

This is PRECISELY why threading in frame is so important! Also any time a print is being screened and it is found that there is a misframe, they could end up scratching the rest of the film. This is why in training it should always be made clear to people that if they ever have to touch the framing knob, they should immediately re-check the loops and shut the system down if they are slapping into anything.

Also an FP25 *could* be used with a platter. [Razz]