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Author Topic: Question about scratches Jeremiah Teague Film Handler Posts: 17 From: Fort Collins, CO Registered: Dec 2008 posted 03-11-2009 06:31 PM                     I've posted before about some scratches I've been getting. The advise I got was to run test reels (trailers) through all the projectors 50 times to determine which Christi P35GPS' are scratching prints. I've found 2 that are. I can't find where the problem lies. Please let me know any ideas you have. Projector #8 (with Dolby Digital Head): (After 15 run throughs) (After 30 run throughs) It's a fairly straight line with a little wiggle. I can't find any protrusions on the projector. Projector #16 (with DTS timecode reader head: (After 25 run throughs) The only thing I can think that would cause this would be having the film ride on top of the sprockets, but this isn't happening (I can't think of the film even running if this were happening). The green dots are very erratic and after more plays, the black cat scratches start to show up.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 03-11-2009 06:45 PM                     I'm sure many others will chime in here with suggestions for both projectors, but one thing I can think of for #16 is your failsafe. If you have the type of failsafe that uses mechanical drop arms, and the film rides on top of bearings, those bearings can be a source of trouble. Although they should only touch the edges of the film outside the picture and soundtrack (except, of course, for the SDDS track), I have seen some where the edge of the bearing rides just inside the image area of the film. Xetron, Big Sky, and "Christie" (manufactured by Speco) failsafes use this type of design. I believe Kelmar does, too, but I'm not 100 percent on that one. Please list your entire setup, as it will help greatly in troubleshooting. The problem very well may not be in the projector head.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 03-11-2009 06:53 PM                        Agreed. What kind of platters do you have? I get the green dots on the right side occasionally, but not that severe. I have Strong platters. I have FPS-350 failsafes which do not have the mechanical drop arms. If the problem were in the projector, the black scratches would probably not move much. HOWEVER I did troubleshoot a theater once that had an old Simplex soundhead and it had two sprockets in it due it its pre-19th century design. It has a small "loop" between these two sprockets and the film would come off the first sprocket when exiting it and lightly rub against the keeper/pad roller, causing light scratches over time that weren't perfectly still.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 03-11-2009 09:34 PM                     You don't have slap guards on the bottom side of your ultramittent and you are making your lower loops way too big. Seen it a million times.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-11-2009 11:06 PM                     When I ran Christies, I had an operator that would make his bottom loop too big and the loop would slap on the holding screw for the stripper. Thus, that slapping would leave a peck mark dead lower center of each frame. I got after him to make the loops the correct way - the way the Christie theading chart would show. Squiggly lines though - isn't that a platter problem since it's more of a continual thing than the side peck marks?  |  IP: Logged Jeremiah Teague Film Handler Posts: 17 From: Fort Collins, CO Registered: Dec 2008 posted 03-11-2009 11:56 PM                     The fail safe is a Component Engineering FM-35. I don't think this is the type of fail safe your talking about, Ken. I may be wrong, though. The platters are chrisie aw3r. I haven't noticed anything wrong with them (film isn't rubbing on the platters or bouncing) but I've never been trained on searching for this type of thing. We do have the slap guards and I've been threading properly since that last topic posted Last Topic . And since these scratches are only happening on 2 projectors, I'm hesitant to say it's human error. I'll take some pictures of the equipment if you think that will help. I really just want to stop damaging prints. It's annoying as hell and I hate not knowing why.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 03-12-2009 05:21 AM                     You are correct; the FM-35 uses a proximity sensor, not the mechanical drop arms I described.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-12-2009 11:59 AM                     These squiggly lines - on the base or emulsion side of the print?  |  IP: Logged Brian Guckian Jedi Master Film Handler Posts: 594 From: Dublin, Ireland Registered: Apr 2003 posted 03-13-2009 04:29 PM                     Also, check the brains in the platters concerned. Make sure there's nothing touching the image area of the film there. Check every single roller from the platter through to the projector for proper rotation, including the rollers in the brain and on the FM-35.  |  IP: Logged Jeremiah Teague Film Handler Posts: 17 From: Fort Collins, CO Registered: Dec 2008 posted 03-15-2009 09:59 PM                     The scratches on #8 appear to be on the base of the film. They are very difficult to see on the film itself. I've already checked all the rollers and the brain. We keep them lubed and cleaned.  |  IP: Logged Gordon Ford Film Handler Posts: 2 From: Wolverhampton West Midlands Registered: Oct 2003 posted 03-16-2009 04:17 PM                     Ok lets look at average film path, now where does the film actually weave like that? not usually on rollers, but in between rollers maybe. So lok at the film path when lacing up and see if anything is close to film when laced up, anything very close to film plane? Look at feed off unit, does film "relax" or drop when not under tension when running? gate area is unlikely as film is under tension and would be stable running, unless you have excessive wear somewhere , but that is likely to show on screen. Without expert knowledge of the equipment you are using, the best advice is lace up a small a trailer and LOOK at all ther film path where weave could occur. The scratches are black so that will be on the base, the emulsion scratches are white or coloured, depending how deep they go and which colour layers are removed. As to the green dots, the most likely cause is on a constant speed sprocket, either has been laced incorrectly, also if this is the case you will find that the scratches could be caused by the one side teeth of the constant speed sprocket,( this would probably be on the emulsion side) therefore being done at the same time as the wavy scratches? or has poor quality machining inside the teeth leaving slightly raised edges, is there a new sprocket? Best of luck in your investigations sherlock LOL Regards Gordon  |  IP: Logged John Wilson Film God Posts: 5438 From: Sydney, Australia. Registered: Dec 1999 posted 03-16-2009 04:34 PM                     Gordon, You registered in October 2003 yet the above is your first post? What took you so long? It's not that frightening here is it? Welcome to another 'active' member.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 03-16-2009 08:45 PM                     Quick question, do the curves in the scratches roll up and down, or is the "curve" of it stationary as far as vertical? (Or are the scratches just all completely random and curved?)  |  IP: Logged Jeremiah Teague Film Handler Posts: 17 From: Fort Collins, CO Registered: Dec 2008 posted 03-17-2009 02:45 AM                     We just recently moved/swapped the digital projector in #9 with the p35 at #8. They did a lousy job setting up the platter tree and the black rollers above and below the head. Another guy and I reset the black rollers (not sure what they're called. they carry the film from platter to head and vice versa) and connecting platter tree rollers. We have not gotten any scratches so far. I don't want to get too excited yet but that top black roller has the base of the film riding on it and if it was rotated wrong, I could see this causing the scratch. I hope this is the issue, but I'm frustrated because that's something I check everytime I hit start. Perhaps some projectors/prints are more liberal in what is acceptable before scratches occur? Brad, the black scratches are essentially lots of cat scratches that form into a uniform line swiveling to the left and right, randomly, in very small amounts. There isn't that much movement, but it is very noticable. I'm sorry, but I'm not sure what you mean by "roll up and down". I hope the above was the answer. I'll keep everyone posted. I'm doing presentation checks all week. For the dots on #16, I've made a loop and I've played it for 10 minutes (which would be about 120 run-throughs if it were a movie). I didn't get any dots on the loop at all. Unfortunatly the film doesn't lay on the bottom and top constant-speed sprokets like it does when running a film. I'm going to figure that out tomorrow. Thanks again for all the help. You guys rock!  |  IP: Logged Gordon Ford Film Handler Posts: 2 From: Wolverhampton West Midlands Registered: Oct 2003 posted 03-17-2009 07:54 PM                     Hi John, Thanks for the welcome, only been a projectionist since 1962, so not as knowledgeable about some equipment as most on here. Have run: Philips DP 70 Philips DP75 Philips/Kinoton Fp20 Kinoton st200/270 cakestands Ross GC3 BTH supa Mainly UK projectors. Have dabbled with Cinemechanica Not a lot. Regards Gordon  |  IP: Logged

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