Film-Tech Forum ARCHIVE: Please help...scratching.

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Posted by Thomas Moore (Member # 3427) on 05-26-2007, 09:11 PM:

Ill make this as brief as possible. Simplex 35 projector head. 5 star sound head. equipment only 7 years old. If looking at the screen crazy weird scratching going on with 2 films now in the exact spot. top right of screen. I checked the entire film path especially inboard for debris or some pad roller that might be deformed. I cannot see any problems. What could i be missing?

Also all the platter rollers look fine and nothing is frozen locked or anything like that that the film may be dragging on.

Thanks for any input.

Tom

p.s. The platter system is cfs/esp 3.

Posted by Gordon McLeod (Member # 33) on 05-26-2007, 09:13 PM:

can you describe the shape and orientation of the scratch

Posted by Michael Moore (Member # 3867) on 05-26-2007, 09:22 PM:

top right? is it a circular scratch? a line, a mark? [Confused]

by the way your first name is my middle

just had to add that.
Mike

Posted by Monte L Fullmer (Member # 2797) on 05-26-2007, 09:32 PM:

I can take a wild guess that the front roller on the middle pad roller assembly is causing your scratching...bottom loop is being built too small..causing the film entering the roller is catching the inner shoulder of the roller.. Check this page out on this topic.

-Monte

Posted by Mark Gulbrandsen (Member # 72) on 05-26-2007, 09:55 PM:

If this is a 1060 with the swing open curved gate then you may be making your loops too large. We have alot of 1060's in my service area and have had alot of scratching problems with them... Two things I've found are that making the upper loop too large causes it to oscillate and cup in towards the top edge of the runner and rub there, this happens to each frame of film as it is being pulled down... the loop of film looses its stiffness with too large a loop. The resulting scratches are usually in the center third of the image and are light lines that appear after a day or two of running a print. I observed this problem by slowing down the film motion with a variable strobe... every 1060 made will do this and I could easily videotape it next time I'm at a place with 1060's if someone would like to see it. A smaller loop stops this oscillating and also creates a stiffer loop that won't cup and rub on the curved runner. Six or seven years ago I started grinding out the top central area of the curved runners between the rails... not surprisingly Strong also began relieving this same area but not until after many years of Simplex projectors scratching film.
Also check the lateral guide roller for excessive squeeze... Strong had a tech in assembly a number of years back that liked to stretch the spring out a bit longer than normal on the lateral guide before assembling it and if this is the case the spring or better yet the entire assy should to be replaced. It may also be stuck in the closed position causing the film to be constantly cupped and runbbing on the runner... you should normally be able to push it open and then it will snap shut quickly. Look at the curved runner's top center area and see if that center area is highly polished.... if more so than on either side of center then your film is more than likely rubbing there... the polished area will be obvious.

Mark

Posted by Darryl Spicer (Member # 711) on 05-26-2007, 10:54 PM:

quote: Mark Gulbrandsen
If this is a 1060 with the swing open curved gate then you may be making your loops too large.

Yes this can happen. When I would train people on the 1060's I would make sure to instruct them to make that top loop no taller than the top of the bolt on the sprocket. If you made the top of the loop at the same level as the whole sprocket then it was to big and would do what Mark desribes.

Posted by Thomas Moore (Member # 3427) on 05-31-2007, 04:10 PM:

Thanks for all the input. By the way the scratching is a vertical impulse, not a continuous scratch that pulses like in and out through the entire film.

Thanks again for input.

Tom

Posted by Michael Schaffer (Member # 1204) on 05-31-2007, 04:22 PM:

The only thing that really helps with the scratching problem is to take a good long shower.

Posted by Chris Slycord (Member # 4239) on 05-31-2007, 05:12 PM:

quote: Thomas Moore
Thanks for all the input. By the way the scratching is a vertical impulse, not a continuous scratch that pulses like in and out through the entire film.

You mean like a small vertical scratch that appears at the bottom of the screen then a moment later appears further up (with the pattern repeating)? If that's what you mean then you should look at either a messed up intermittent. Also, if you clean your projectors with toothbrushes it's easy for one of the hairs/strands to get caught in the roller. And it's obvious when it's on the intermittent.

Posted by Mike Blakesley (Member # 26) on 05-31-2007, 10:33 PM:

Uh, there's no way an intermittent can cause any kind of a scratch.

A single small vertical scratch that travels up the picture and then repeats is probably caused by too large a loop (film banging on the projector casing and getting scratched by a small burr in the metal, maybe).

Multiple scratches that travel up are probably caused by the film riding on the sprocket teeth, or if the scratches are diagonal, they could be caused by the film dragging on the platter or a roller.

Posted by Chris Slycord (Member # 4239) on 06-01-2007, 02:56 AM:

Yeah that could cause it.

But I still remember getting occasional scratches from the hairs of toothbrushes getting caught in the gears and sometimes causing that.

But I'm admittedly not an expert.

Posted by Thomas Moore (Member # 3427) on 06-01-2007, 02:42 PM:

Well I am in the process of checking everything that was said here. I just cannot seem to find anything out of the ordinary. I've taken off all the pad rollers also aand inspected them. didn't see anything wrong however I replaced the one below the gate like someone advised. Is the loop to small at the gate if the first roller is spinning because I have heard both yes and no on whether or not the pad rollers are actually suppose to spin.

Posted by Jeremy Weigel (Member # 4208) on 06-01-2007, 02:59 PM:

Is the scratch on the emulsion side or the non-emulsion side of the film?

Posted by Thomas Moore (Member # 3427) on 06-01-2007, 05:06 PM:

not exactly sure about what side yet. been runni9ng it all day and i havent been at that theatre to check it today. All I know is that the scratch is a light black scratch that is not solid through the entire frame and its like an intermittent pulse type affect.

Posted by Jeremy Weigel (Member # 4208) on 06-02-2007, 01:39 AM:

Black scratches are usually on the non-emulsion side of the film. I would check to make sure that there isn't any debris on the sound drum(s).

Posted by Thomas Moore (Member # 3427) on 06-21-2007, 04:29 PM:

Well I ran a loop through the projector head and the sound head only, for about 30 minutes. No scratching at all occurred. I did find one of the rollers on the brain was slightly dragging so I replaced that. There is nothing else I can see in the film path out of the ordinary to or from the projector unless I'm totally overlooking something.