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

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Gate Maintenance

Author Topic: Gate Maintenance Ian Bailey Master Film Handler Posts: 317 From: Nambucca Heads, Australia Registered: Jun 2003 posted 08-02-2004 08:34 PM                     I have 2 Simplex 35 projectors whose gates have never had any parts replaced in them.They would have to be 25-30 years old and still running.I will be replacing the tension springs.The bars that rest against the film edge are worn but still appear to be in useable condition.Are there any other parts that would need replacing? Could someone explain to me how you adjust gate tension correctly(I know you turn the KNOB but how much tesion is required?) What indications on the projected image do you get when gate tension is not correct. I can wind the gate tension knob from zero to full on these gates and not see any difference in the stability or look of the projected image. Any help will be much appreciated Ian  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 08-02-2004 08:50 PM                    Generally, the lowest tension that keeps the picture steady under all normal conditions and film stocks (snipes, trailers, feature). Lower tension reduces wear on the intermittent sprocket and on the intermittent movement that drives it.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 08-02-2004 09:17 PM                        quote: Steve Kraus Lower tension reduces wear on the intermittent sprocket and on the intermittent movement that drives it. Lower gate tension also reduces wear on the print, including a reduction in the scuffing projector abrasion of the SDDS and Dolby Digital soundtrack areas and sprocket tooth deformation of the film perforations. As Steve says, just enough tension to get a steady image.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 08-02-2004 09:23 PM                        If adjusting the tension doen't make any difference (at one point when you turn the tension down, the image should start jumping unless the gate bands are new), you can also check how far the gate pushes into the trap. There is a stop screw just beyond the aperture which you can adjust. When you install new gate bands, you can work with that and see that you put as little tension on the film as is just necessary.  |  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.