my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Filter sliding down on Christie brain

Author Topic: Filter sliding down on Christie brain Manuel Francisco Valencia Expert Film Handler Posts: 151 From: Oklahoma City, OK, USA Registered: Dec 2000 posted 05-14-2001 03:20 PM                     I have this problem on two platters now. The arm on the brain always stops at about 50 degrees and cannot go any further because the filter has slid down its shaft and is hitting the take up bar. I always lift back up and tighten it into place but it always comes back down. When it happened to the second platter I felt an awful lot of what seem to be lubricant. Is it possible that the bearing above the filter broke and the lubricant ran out?  |  IP: Logged Paul G. Thompson The Weenie Man Posts: 4718 From: Mount Vernon WA USA Registered: Nov 2000 posted 05-14-2001 05:21 PM                     Sounds like a loose screw on a retaining collar around the shaft.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 05-14-2001 05:30 PM                     It's hard to say without looking at it. There could be any of a dozen things wrong with it. First thing I'd do would be to take a look and make sure the screw that holds the filter card in place is securely tightened on the shaft. Tighten it and then wiggle it. Tighten it again if it needs to be. Sometimes if you get the thing on the shaft at a slight angle, the screw can't "grab" onto the shaft and will come loose later on. This is especially important for drive gears inside projectors and things but it is a habit for me to do this on almost everyting where a set screw is involved. On one occasion I found that somebody had done some work on the platter and removed the bearing. When it was replaced this person didn't make sure the bearing was seated all the way down in its "groove". A little bit later on, it decided to seat itself. (Because of the pressure of the brain pushing down.) When this happened the shaft moved down and messed up the payout. Whatever the cause, you'll find it's a pain to work on the payout mechanism by reaching in through the little portal on the end of the support arm. Unless it's a quick repair, I take off the whole deck and remove the axle assembly by loosening the four bolts that hold it onto the arm. It's much easier that way. Just don't forget to put the three "donuts" (bearing rings) back on the axle and get them in the right order!  |  IP: Logged Joe Grace Film Handler Posts: 44 From: Maine Registered: Feb 2000 posted 05-14-2001 08:08 PM                     I have had this same thing happen to me a few times, but it doesent happen as often. Maybe try a new screw or a new filter. It could be that something like the threads are worn. Joe  |  IP: Logged Jon Bartow Master Film Handler Posts: 287 From: Massachusetts Registered: Nov 1999 posted 05-14-2001 08:31 PM                     I have had several do just what you are describing. Take the axle assembly out and remove the filter (a.k.a. "variable density disc). Look at the shaft that the filter mounts to. Sometimes the set screw makes an indentation in the flat area of the shaft. If the indentation is deep enough then you will have a very hard time getting the set screw to tighten anywhere else. If that is the case order a new shaft and bearing. Of course don't dissasemble anything unless you know how to put it back together properly  |  IP: Logged

All times are Central (GMT -6:00)

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.