Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Prints shedding on Simplex

   
Author Topic: Prints shedding on Simplex
Andy Uhrich
Film Handler

Posts: 3
From: Chicago, IL, USA
Registered: May 2005


 - posted 07-12-2005 11:33 AM      Profile for Andy Uhrich   Email Andy Uhrich   Send New Private Message       Edit/Delete Post 
Hi,

We have a couple of Simplexes and black and white prints shed horribly causing the picture to go out of focus, often to the point that it can't be put back in focus. Once the shedding was so bad that the print got stuck in the gate and the frame burned. Does anyone have an idea of what is causing this and what can be done to stop it.

Thanks for you help,

Andy

 |  IP: Logged

Randy Stankey
Film God

Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99


 - posted 07-13-2005 11:08 PM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
The exact model number (PR-xxxx) will help us help you a lot better.

Check your gate area first.

Make sure there aren't any burrs or nicks or anything like that which will scrape the film. Look on the gate runners, the tension bands and any "film-bearing surfaces". Make the same check on the intermittent sprocket pad shoes. Then make a similar check on all your sprockets, pad rollers and anything else that the film touches.

If you have checked all of that and you STILL haven't found the cause you're probably going to have to call your technician and have him check your gate tension and alignment.

Throughout all of this, we are, of course, assuming that the film is always threaed correctly and isn't touching anything it's not supposed to.

Here's the kicker: Once the film is "scuffed" it will continue to shed even AFTER the problem that caused it has been solved. It my get better after a while but it will never go away completely. If you put another print through that projector without solving the problem first you will damage another print FOREVER.

Your best plan of attack is to take a vacuum cleaner hose and a paint brush and give that projector a super-duper cleaning. Then take some old trailers and splice them up into one long "mini-movie". Run them through about a half dozen times. Then look inside the projector to see where the most dirt is. With a litte luck the pile of dirt inside the projector just might lead you to where the problem is. If not, you can use that film as a "telltale" to see where the damage is coming from. More on that later... if we even get that far.

Go check for a damaged gate, etc., first. [Smile]

 |  IP: Logged

Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 07-13-2005 11:22 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
True, Randy's asking what kind of "PR" machine you have (a PR-1014,1050,1060..etc..), or do you have an old black case "XL" machine?

I had the similar experience with PR-1050's with one machine had the trap and gate (flat gate and trap style) that the gate was closing too tight and causing shedding.

If's a 1014 or later, there is a stop allen screw located on the inboard side of the trap that "stops" the gate at a certain point when closing the gate. This allen screw will turn in to cause the gate to close too tight and will shed film like mad.

If's it the flat gate style, the runners and guides on the trap could be worn, wear spots and grooved to cause this problem.

-Monte

 |  IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999


 - posted 07-14-2005 05:41 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Pssst. Monte...even "XL"s had "PR" numbers. The first PR-1014s was a black wrinkle finish. The "PR" number will let us know exactly what machine you have and if further questions need to be asked.

 |  IP: Logged

John Walsh
Film God

Posts: 2490
From: Connecticut, USA, Earth, Milky Way
Registered: Oct 1999


 - posted 07-14-2005 07:08 AM      Profile for John Walsh   Email John Walsh   Send New Private Message       Edit/Delete Post 
Is it with B&W prints only? I've run several B&W prints that shed. It would also happen with IB prints. There was a hard, dark-white colored build up on the gate bands. The build up could be little on one side of the gate, while a lot on the other side, resulting in the image out of focus on just one side. A through cleaning after every show was the only thing I found that reduced the problem, but even then it was pretty bad after 8 weeks.

 |  IP: Logged

Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-14-2005 10:45 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Black and white filmstocks tend to shed in pretty much every projector, even one which is not scuffing the print in any way. I'm sure there will be people who will argue the point that if everything was absolutely perfect with the projector that this wouldn't happen, but in most cases you will drive yourself insane trying to track down the cause if you don't also experience that kind of shedding on color prints.

Just get yourself a bottle of FilmGuard. It will stop the shedding.

 |  IP: Logged

John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 07-14-2005 03:34 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
Kodak has recommended proper lubrication of prints after processing since the 1920's, to reduce projector abrasion of the film. The recommendation is in Kodak's processing manuals, and in SMPTE Recommended Practice RP151. Unfortunately, restrictions on the use of solvents to edgewax film have caused most laboratories to not lubricate prints (e.g., methyl chloroform / 1,1,1-trichloroethane depletes the ozone layer).

Kodak does put lubricants into the film formulation, but there is a limit to how much can be added without making raw stock rolls too slippery.

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

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.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.