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Author Topic: Scratch Problems Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 12-29-2004 05:14 AM                     Course, we outsiders have to ask the simple questions of: 1-what kind of visual scratches are they - line or lateral, black or green. 2-Base or emulsion scratches 3-Scratches on the side of the image, or down the middle. Course, I trust that you know, with a Century upper feed film load that the loops size is created with the opened pad roller-film looping over and touching the pad roller before closing the pad roller assembly is the correct upper loop size. Big one is we have to watch out for is: does the lower pad roller assembly have "shouldered" rollers-rollers with small inner shoulders where the sprocket teeth go between the outer shoulder and this "inner shoulder". The "shouldered" rollers have a tendency to imprint massive scratching on the base side of the prints on both sides just inside of the sprocket hole layout. I'm sure that you've might have seen many-a-prints with this form of scratching. Also, we know that the lower loops size is like the upper size - made with the pad roller assembly opened. (have to ask..) With the more detailed of what the scratches are, then maybe more help can come your way on helping with your scratching problem. good luck- Monte  |  IP: Logged Carl Martin Phenomenal Film Handler Posts: 1424 From: Oakland, CA, USA Registered: Feb 2002 posted 12-30-2004 02:30 AM                        yes, i didn't fully describe the scratches because they seemed to fit the earlier description. extreme right side of picture area, base side. vertical, sort of standing, but not quite. actually, because of cropping and keystone issues, they only show in certain formats, on certain screens. looking at the film itself, it looks like a scuffed area extending maybe 1-2mm from the inside edge of the perfs. on the msa, we do make the upper loop as you say, but the lower loop is determined by getting the sound sync and tension correct. in any case, it works out to about the same, i think. our pad rollers do have these inner shoulders that you speak of. i thought all pad rollers did. i spent some time with a little mirror looking at where those "shoulders" fall on the threaded film, but there's enough play in the rollers on the shaft that that wasn't very conclusive. today i threaded some scrap film and while running it, opened the upper and lower pad rollers a bit. within seconds, i started to lose the loops (no splices or other incongruities passed through). since the rollers are necessary to keep film on these sprockets, and the only way to do so is to be in contact with the film, it affirms my feeling that indeed the rollers should be spinning during the show. this is in contrast to the sprocket underneath the sound drum, where there's no loop flapping about. carl  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 12-30-2004 05:06 AM                     quote: Carl Martin extreme right side of picture area, base side. vertical, sort of standing, but not quite. actually, because of cropping and keystone issues, they only show in certain formats, on certain screens. looking at the film itself, it looks like a scuffed area extending maybe 1-2mm from the inside edge of the perfs. Yeppers. It'd be those "shouldered" rollers doing this nasty little scratching, esp with the rollers on the lower feed sprocket pad roller assembly. Change those rollers out to the "unshouldered" variety, and I trust that your scratching problem will cease. I'm an engineer for a local bunch of theatres with Simplex 1050's and every theatre were complaining of this similar scratching-the extreme right on the screen-either scope or flat. It turned out that the lower pad rollers were the "shouldered" variety. We changed them out to the "unshouldered" variety and the scratching is gone. This scratching is caused by when the film is entering the roller assembly after leaving the gate and the film is touching the inner shoulder of the roller first before being pulled around by the sprocket. This is also where you mentioned of the flat spots on the rollers-the initial film contact of any surface. Next time when a film is being run though these machines, look how the film leaving the gate enters into the lower pad roller assembly, and you'll see the film, as it's being pulled by the lower constant feed sprocket, actually rubbing against the inner "shoulder" due to the initial contact as the lower loop is growing then collapses. Good luck on this cure. - Monte  |  IP: Logged Joshua Burnham Film Handler Posts: 43 From: Rainier, WA, USA Registered: Feb 2003 posted 01-02-2005 03:48 PM                     Hello, I had similar problems with the Christie AW3r's center-feed film position tips wearing grooves and leaving what we referred to as "angel hair scratches". I couldn't say if this is the same issue being described but maybe? Also what sort of oil do you use to lube pad rollers? Where would you apply it on the shaft underneath the roller I am assuming? What about Xekote or similar brands does anyone else use this? If so how often? I look forward to your comments. Thanks In Advance, Josh  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-02-2005 09:55 PM                     quote: Joshua Burnham I had similar problems with the Christie AW3r's center-feed film position tips wearing grooves and leaving what we referred to as "angel hair scratches". I couldn't say if this is the same issue being described but maybe? Also what sort of oil do you use to lube pad rollers? Where would you apply it on the shaft underneath the roller I am assuming? Do you have any of the "Lubriplate" tube grease to relube the tension spring that the center roller is attached to on the brain? Might be needing some relubing for the roller could be way too tight and cinching the film as it pays out from the brain to the tower rollers. One can use any teflon lubricant, esp like "Tri-Flo" for pad roller lubrication. Take the pad rollers off, clean the shaft and the inside of the rollers with a "Q-tip" soaked in a grease cutting solvent (Film-Guard is also good for this..) and relube the shaft with the teflon spray. thx, and good luck - Monte  |  IP: Logged

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