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Author Topic: Failsafe Close Call Edward Jurich Master Film Handler Posts: 305 From: Las Vegas USA Registered: Jul 2003 posted 09-13-2003 09:39 AM                     The failsafe had stopped working, would not shut the projector off. We ran that way for a couple weeks. I tore into it a couple days ago and fixed it. Last night during a 10PM showing of Monty Python Holy Grail, about 2/3 into the film the projector stopped. I ran in and found the film had wrapped around the payout causing the failsafe to shut the projector off. Talk about being lucky, hate to think what would have happened if the failsafe had not been working.  |  IP: Logged Don E. Nelson Expert Film Handler Posts: 138 From: Brentwood, CA, USA Registered: Nov 2001 posted 09-15-2003 03:03 PM                     How does a fail safe work, I have never seen one.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 09-15-2003 03:10 PM                        A tension-sensing failsafe runs the film over either a weighted or spring-loaded roller, usually mounted on the platter column monitoring the film feed from the platter to the projector. When excessive tension builds, the roller is pulled such that it trips a microswitch or magnetic proximity switch, sending a "shut down" signal to the automation. Better systems use a "trolley" system to allow enough film slack to let the projector coast to a stop without tearing film or perforations. Tension sensing failsafes are available from most of the major platter manufacturers (e.g., Strong, Speco) and from vendors like Kelmar and Avask. Kodak still recommends always using a tension-sensing failsafe with polyester prints. The other "fail-safe" is a film break detector, that usually also functions as a end of film detector. These will NOT protect against buildup up tension between the platter and projector.  |  IP: Logged Edward Jurich Master Film Handler Posts: 305 From: Las Vegas USA Registered: Jul 2003 posted 09-15-2003 04:18 PM                     The platter has a payout failsafe using a tension roller that pulls up if the payout jams. The projector has two ball bearing rollers that ride the edge of the film (both sides) located after the film exits the projector just above the takeup spindle. If the film breaks or slits, one or both of the rollers drop and stop the projector.  |  IP: Logged Chris Hipp Phenomenal Film Handler Posts: 1462 From: Mesquite, Tx (east of Dallas) Registered: Jul 2003 posted 09-15-2003 04:55 PM                     tension sensing failsafes are also known as wrap detectors.  |  IP: Logged Carmine Occhino Film Handler Posts: 27 From: New york city Registered: May 2003 posted 09-15-2003 09:10 PM                     how much does one of those wrap detectors cost ?  |  IP: Logged Chris Hipp Phenomenal Film Handler Posts: 1462 From: Mesquite, Tx (east of Dallas) Registered: Jul 2003 posted 09-15-2003 09:21 PM                     Im sure it would vary depending on your equipment, but it is a pretty simple device so it shouldn't be too expensive. [ 09-16-2003, 12:29 AM: Message edited by: Chris Hipp ]  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 09-15-2003 09:29 PM                     I depends a bit on the make of plater it will be fitted on?  |  IP: Logged Carmine Occhino Film Handler Posts: 27 From: New york city Registered: May 2003 posted 09-15-2003 09:33 PM                     neumade xetron 5 platter  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 09-16-2003 10:01 AM                        Here is the "Optional Platter Failsafe" (NXPFS) made by Neumade: http://prosites-clementsx.homestead.com/platters~ns4.html  |  IP: Logged

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