This is topic Green Band Scratching in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by David Whitbeck (Member # 894) on 07-23-2001, 12:36 PM:
I'm running a Simplex 35 with a 701 penthouse reader and an SH-75 soundhead down below. The 35 has a 3 pad studio gate with forward/reverse tension shoes. The green band is scratching on the soundtrack side and it's leaving quite a mess. I've had piles of shavings after a show. I've checked over everything again and again and I can't find where it's scratching. Any ideas?
Posted by Matthew Bailey (Member # 601) on 07-23-2001, 12:53 PM:
It could be your trap & gate.Remove & dismantle the gate & trap
& check for gouges,scoring,burrs & rough spots. You may have to remove
& check the sprockets& pad rollers & strippers on the sprockets.
Check the intermittent shoe also,& the sond drum & all
rollers & lateral guide roller assembly in sound head.
Check readers & see if theyr'e scraping the film.
Whether your'e running reels or platters, run a test film
unscratched & eye each part of the film path & figure out what
is scratching the soundtrack.
Posted by John Pytlak (Member # 331) on 07-23-2001, 01:19 PM:
Ditto to Matthew's suggestions.Which side (emulsion or base) is being scuffed/scratched by the projector? If you don't see a scratch, it may be that you are scuffing the film edge or chipping away at the perforation area.
Look first at the area in the film path where the skivings are building up.
The "pile of shavings" can be identified by some simple tests:
Gelatin emulsion will dissolve in laundry bleach (sodium hypochlorite) and usually has color. Under a microscope, you can see the structure of the dye-containing layers.
Acetate support will dissolve in splicing cement.
Polyester support is impervious to most solvents, including splicing cement.
------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
Posted by Matthew Bailey (Member # 601) on 07-23-2001, 04:23 PM:
From what you & John mentined,it's probably the SDDS track.
Which part of the soundhead & projector are the shavings accumulating?