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Author Topic: vertical film scratches Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-18-2005 04:55 PM                     We have a projector that is producing vertical film scratches. In a horizontal row across the upper 1/3 of the frame. covering the middle 1/3 of the frame. the scratches are 1-2 mm in length. We have run film loops through the intermittant area. scratches appear after 5 minutes of looping. (approximating 100 showings.)Through the intermittant and avoiding the sprocket above the sound head. scratches. through the upper film guide projector roller from platter to dts to intermittant area through sound head all the way down and skipping fail safe. scratches. scratches not from sound drum. scratches isolated to intermittant, trap and the intermittant sprocket below trap area but not through sprocket above sound head. scratches. by changing the size of the film loops to the pad roller arm setting on the sprocket below and 1 sprocket shorter than pad roller arm above the trap, I have so far ran 1 showtime and not produced the scratches. equipment: Projector century LC/AC/SA. Century autowind 2 platters. PS Discovered upper sound head pad roller. Plastic roller has a flat spot on soundtrack bearing part of roller. We have changed out the trap, gate shoe(the curved part that pushes film into trap has some wear and possible dent on upper left runner.) We have changed out the intermittant and replaced all components on trap. We replaced the screws and holders for the aperture plate in the film path area. Realigned the "gate shoe" to the trap. None of the components are creating the same scratches in the other theatres with identical equipment and now the components from this theatre. We could replace gears in back of projectors and shafts. we could replace sprockets and pad rollers. we could replace trap and "gate shoe". Running out of ideas. A film scratch detection system kit was mentioned on one of the film tech forums. I have examples of scratches I am going to try to scan to a jpg. and will try to share with forum. Contact info deleted - pay attention to the rules [ 06-19-2005, 04:01 AM: Message edited by: Brad Miller ]  |  IP: Logged Jason Miller Expert Film Handler Posts: 241 From: Little Rock, AR, Registered: Mar 2004 posted 06-18-2005 06:06 PM                    are they base side or emulsion side? if emulsion side, what happens if you run film for 5 minutes without the aperature in it?  |  IP: Logged Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-18-2005 08:09 PM                     emulsion side scratches as they are clear or black. tried without aperture plate but still scratched. I will try again though to be sure. I am wondering if the little clips that hold or guide the aperture plate maybe the scratching culprit. Sorry I didn't check back sooner. New to this posting process I am.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-18-2005 09:41 PM                     Mike, There must be emulsion deposits to give you a clue as to where the scratching is occuring. If the clips are doing the scratching then either they are bent towards the film, or the gate mechanism is set too far into the trap itself. You ought to give Monty Fulmer a call and have him take a look at it for you, he can figure it out. What type of platter is in that booth? Platters can also cause this type of scratching....... Mark @ CLACO  |  IP: Logged Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-18-2005 10:05 PM                     i know the scratches occur with a film loop. sans platters. but i have read on the forums and have seen your posts about platters. I am going to check on the next show and see if the scratches show up. so far i found one scratch after several showings in dead center picture and one upper right area of picture sound track side. I need to check a single frame of a trailer i put on earlier today and see if more scratches have shown up in a different part of trailer. Thanks for your attention. I will call monte. Thanks Mike  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-19-2005 03:30 AM                     Yea, I know that booth. Centurys, Autowind 3's, Super Lume-X with overcooked 2k Osrams, RAVEN Commander automation, USL JS-200 series...et.al. I could live in that booth being the many, many things that needs to be done to that place.. Welcome to the Forum, Michael. I've been doing work at the Terrace as well in getting her Century SA up to snuff. Yea Mike, give me a holler if you need help on this. Be glad to help you out. -Monte  |  IP: Logged Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-19-2005 04:38 AM                     how do i adjust gate tensioner in. I am trying to back it off using gate housing 4 mounting bolts. Wondering if the cylinder moves back inside this gate housing assembly as well. century projectorLC/AC/SA Thanks Mike Sherbert.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-19-2005 08:13 AM                     Mike, The insturctions for adjusting that are in the SA Manual. It might really be best to call Monte over...he's pretty good at solving those problems. If you're not sure what you're doing then don't adjust it! Might cause even more problems than you have now!! Monte is a qualified technician by my standards. Typically, cinemas that fail to get qualified technical assistance exhibit problems such as yours. Mark @ CLACO [ 06-19-2005, 09:40 AM: Message edited by: Mark Gulbrandsen ]  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-19-2005 11:37 AM                       Take a brand new piece of film - a new trailer or something - and run it in the machine. Somewhere in the middle of the film, stop the projector. Take a Sharpie marker and mark the film where it enters each sprocket/pad roller, above and below the film trap, the intermittent pad shoe, failsafe... etc. Remove the film and look for where the scratching stops. Your marks will tell you what part of the machine is causing it. If the scratching is taking a very long time to manifest itself this may not work, but it's worth a try.  |  IP: Logged Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-19-2005 01:25 PM                     i have nailed it down to trap. If i run sans trap and physically hold film against gate shoe. No scratches. Once trap is in place it scratches. whether i remove the aperture plate and the plate keepers and screws in the film path makes no difference. I have backed the gate as far as it will go with out picture flutter. Still scratches. and now they are continuous scratches. I am calling monte. I think i will try the film marking method just mentioned by one of the gentlemen in forum. thanks mike any ideas keep them coming. I ran a green header from a trailer for a couple seconds with marks at different points. I find the scratches start in the sound head and continue. I think its possible that it is scratching in multiple places. This is most confusing. And yet it wasn't scratching earlier sans trap and through the sound head. I will run another leader through and mark exact placement with marker labeling lower trap edge etc. and advance 1 frame and then remove film and examine film. I called and left message for monte.  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-19-2005 02:37 PM                       No, no. You can't run the film in a loop, because then the marks will be useless. It's probably a good idea at this point to get a skilled tech to come in. Indeed, Monte knows his stuff.  |  IP: Logged Michael D Sherbert Film Handler Posts: 6 From: Caldwell, ID, USA Registered: Mar 2004 posted 06-19-2005 04:02 PM                     i didn't run the film in a loop. just a short piece of film that i was very careful threading and basically switched on motor and back off. scratches run continuous now. Monte scheduled for 6:30 arrival. I am going to run another short piece of trailer and advance it one frame and see if it scratches and where it starts exactly. i'm going to keep working on this. thanks for all your help. mike  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-19-2005 05:13 PM                     Thx for the compliments on my "figurin-out" skills - I kinda have a knack for such things, if I pay attention enough (lol). Yes, doing the trailer thing helps to find that "footprint" that I need to decifer and deduct such trails of any scratching. thx-monte  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 06-20-2005 06:59 AM                     For something like this..., I generally take a RED sharpie and mark up the scratches pretty heavily (this is on the scrap film that you run to find where on the film it is scratching). Then run the scrap film again and look for the RED dust trails...it should point right to the culprit.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-20-2005 10:59 PM                     I think I got it cured without any form of adjustments - called "operator error" of sorts. Operators building their lower loops too small and loop smaking against the lower constant feed sprocket pad arm hub assembly. For I ran a trailer as Tim mentioned through the machine without any usage of guidance rollers - just held the roll above the machine and let the film pile on the floor after the film exited the machine. Then picked up the end, that wasn't touching the floor, to see if I can see any scratching on either side of the film. Film was clean-no scratches on either side. Course, I threaded up that Century to loop specs with the intermittent assembly in the center of the vertical frame travel. I did see the results of such scratching on the feature that was being presented, and the scratches, on the screen, were upper center screen lateral scratches that was a constant frame scratch-this scratch being in the same place at each frame, not a line, or linear scratch if was caused by rollers or a dragging problem. -Monte  |  IP: Logged

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