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

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Simplex Tension Band adjustment (Page 1)

This topic comprises 3 pages: 1  2  3

Author Topic: Simplex Tension Band adjustment Nicholas Stevens Film Handler Posts: 6 From: Munroe Falls, Ohio, USA Registered: Feb 2008 posted 03-01-2008 04:02 PM                     I have been searching the forum's and have not found a post on the proper way to set the tension on the film for a simplex projector. Can someone either point me to a post or explain the proper way to set the tension? Thanks in advance  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 03-01-2008 05:52 PM                        You want the least amount of tension possible to achieve a steady image.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 03-01-2008 07:41 PM                     Sean is absolutely correct. As far as how to perform the adjustment, you can find the instructions in the manual, which can be found in the manuals section of this site if you do not have one. Basically, on the outboard side of the film trap, you will see a knurled knob with 5 numbers on it. Each of these numbers represents an increasing amount of tension, with 1 being the least tension and 5 being the most. Start with the tension all the way down, and only increase if you need to in order to obtain a steady picture. If your picture is steady, don't go any tighter than necessary. I beleive that tension knob is common to all models of Simplex. At least all that I am familiar with.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-01-2008 11:42 PM                     Only sight variation in tension is when using either Acetate or Polyster prints since "poly" film is slightly thinner than the acetate based prints. And even such, "poly" film does have it's variances in thickness where adjustments are still necessary - but the norm still holds true: less tension the better. Flat gate XL's had their tension knob on the gate itself since it adjusted the pressure of the the gate rails into the trap rails, whereas the curved gate units had the tension knob on top of the trap being behind the upper part of the bands and this either made the bands more slack or more tighter.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-02-2008 08:37 AM                     quote: Sean McKinnon You want the least amount of tension possible to achieve a steady image. Dudes... I find that line absolutely hilarious ! With the amount of unsteadiness we typically see in the crapo release prints of today I am finding more and more Simplex's, Century's, Christies, Norelco's, etc., whose gate tension is turned all the way up in an effort to get something stabilized on the screen. Of course these "booth mongers"... some of which are adults... can't blame it just on the kids... think they're doing their job correctly in doing so. We tell em not to turn it past 2:00 on the dial NO MATTER WHAT but by the next visit there's someone else running the booth as the last "Monger" is now the manager over at McDonalds! We rebuild alot of intermittents because of this... Doesn't seem to affect the Ultramittents though for what ever reason, perhaps more attributable to the synthetic oil in them than the actual internal parts which are identical in size to Simplex X-L. Thank God Digital Cinema is just round the corner.... At any rate you may want to revise that "standard booth line" to say... "If you have to turn it past 3 on the dial its probably not going to get any steadier so leave it at 2 to prevent excessive mechanism wear." Mark  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 03-02-2008 09:52 AM                        Maybe I should have said "You should use the minimum amount of tension needed to stop unwanted motion of the film in the gate" How much should we be willing to alter our practices due to lab errors? What if release prints start to come out all with the same misprinted SR*D tracks what becomes correct? To calibrate the readers to pick up the misprinted tracks or to achieve dolby spec. ? All in all I think the labs need to get thier acts together.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-02-2008 10:30 AM                     quote: Sean McKinnon Maybe I should have said "You should use the minimum amount of tension needed to stop unwanted motion of the film in the gate" What you said makes perfect sense to those with an IQ above 63 but remember the projectionists/managers out here typically are under IQ 63. So this is what I teach them.... You can rarely stop that unwanted motion any longer even if there were a gate pressure setting of 25 . The 1:00 to 2:00 position "should give optimum results" (assuming the projector is set up properly). Any more than that is excessive and will put unwanted wear and stress on the mechanism and they will be taking the repair charges out of your paycheck. I assume the latter threat is why they all seem to flee over to McDonalds. Mark  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 03-02-2008 11:05 AM                     Mark, I thought that excessive tension will only wear the bands faster (and put unnecessary stress on the film, of course). How does it affect the intermittent?  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 03-02-2008 11:28 AM                        I see what you mean and completely agree with you Mark, I just like to play devils advocate sometimes Excessive tension will cause more drag on the film causing the starwheel and cam to have to work harder to pull down the film. The more stress when the cam comes into contact with the starwheel will cause them to wear that much faster, and develop flat spots. The more the mechanism has to work to pull the film down the more stress on the drive train also causing fiber gears to wear etc...  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-02-2008 12:22 PM                     Three pieces suffer the most from excessive gate tension in this order: 1.Pin on the cam develops a flat spot where it strikes the slot during pull down. This development of a flat spot is normal wear over many years but is much accelerated with higher gate tension. Synthetic oil really helps in this department because it holds up much much better under the high pressures involved when the pin strikes the side of the slot. 2 Slot in the Star wheel wears faster from the extra pressure being exerted on it by the cam pin. A seriously worn slot will actually look wavey... you can fel it if you run your finger nail along the edges of the slot... 3.Face of the teeth on the intermittent sprocket become undercut faster. 4.Gate Bands will wear faster in certain spots but generally not all that much. What you get though is a stretching of the gate bands and a resultant lower tension once they become stretched. This is especially true of Apogee, Christie, and DP-70 gate bands... those machines whose bands are quite long. Mark  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 03-02-2008 12:27 PM                       quote: Mark Gulbrandsen We tell em not to turn it past 2:00 on the dial NO MATTER WHAT The numbers are irrelevant. Tension depends on how deep the gate closure is set.  |  IP: Logged Nicholas Stevens Film Handler Posts: 6 From: Munroe Falls, Ohio, USA Registered: Feb 2008 posted 03-02-2008 12:53 PM                     Well I understand that the tension knob should be set at the lowest number possible but my real issue is that the gate's (swing open style) are not all set correctly so the tension knob on some of the projectors are all the way up and some are not. Should I adjust the gate's to be tighter or looser depending on the setting of the tension knob to get the knob's to be on the lowest settings without the film jumping all over the place?  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 03-02-2008 02:37 PM                        What Mark says makes a lot of sense as well there is a lot of printed side to side movement in the prints we receive now and some up and down bob as well. No amount of adjustment can right what the lab hath done wrong. There is also a matter of some of the camera's used in filming are in need of being maintained now and the lab can't correct film that is traveling side to side and bobbing up and down when it is being filmed. It is rather upsetting to use pattern film to ensure that the film is traveling right and the tension is set well only to run a movie that has bob and weave that you can do nothing about! As to setting the proper tension I would set the settings at the lowest number and adjust the large coil spring (using a test film loop such as Schneider Test Film CLT 2000). Adjust the coils until the jump and weave stops but use some kind of test film so you know it is printed stable!  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-02-2008 07:43 PM                     quote: Tim Reed The numbers are irrelevant. Tension depends on how deep the gate closure is set. Well ah Tim... there are standards for that setting on most American built projectors. If there are not then you go by ounces of tension while using a guage to determine the normal running pressure... quite elementary really! Mark  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-02-2008 07:44 PM                     quote: Tim Reed The numbers are irrelevant. Tension depends on how deep the gate closure is set. Well ah Tim... fortunately there are standard depth settings for most American built projectors so those numbers can actually serve as a refrence if you want them to. Some projectors gates click shut and have no adjustment for depth. If there are not specs as on some European machines then you go by ounces of tension using a scale guage(looks like one of them thare Fish weighn scales cept lots more accurate!) to determine the normal running pressure... 10 to 12 ounces of back tension is what is generally consdered Mid Scale er setting 3 on an X-L on that thare tension knobby. Quite elementary really! Mark  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

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.