Film-Tech Forum ARCHIVE: Dust in gate

This is topic Dust in gate - Cinemeccanica in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Antonio Marcheselli (Member # 373) on 07-21-2003, 04:09 PM:

Hi everyone

I had a digital camera for a while so pls excuse me for multiple posts, but I have few questions that I want to share with you!!

First, look this aperture plate:

Do you see the dust around it? I have few projectors that have a lot of dust around the aperture plate as you see in this one (but here is less). Usually the same projectors causes damages to the prints.

What is it? Pression is at minimum, gate is cleaned every day.

Bye
A

Posted by John Walsh (Member # 168) on 07-21-2003, 09:27 PM:

Looks like a V5 or V9 gate. I'd say that is a normal amount of dust running one entire print.

The trap has been removed. What does it look like?

Posted by Mike Rendall (Member # 1499) on 07-22-2003, 03:00 AM:

Dust can be attracted to the gate by static. You have a plastic film running through and rubbing against metal parts - A mini van-de-graaf generator. If the gate does not seat to the backing plate properly there can occasionally be a poor circuit to the projector and hence no grounding (or poor grounding at best). This may be attracting the dust.

It should be quite unlikely since most projectors are metal cased with a pretty firm earthing point somewhere.

Posted by Carmine Occhino (Member # 1699) on 07-22-2003, 07:22 AM:

What kind of damage is caused to the prints? I would also like to know what the trap looks like because I run V5's and a hard type of debre builds up and I was curious if you get that too. (Another theatre that runs a slightly different model doesn't seem to get that type of debre..and the projectors are cleaned a lot less [Mad]

)

Posted by Darren Briggs (Member # 1071) on 07-22-2003, 09:46 AM:

I have had this sort of dust occur on my vic 5's, but it only happens once in a while, and leaves dust all over the film path.

I was told that maybe its part of the anti-halation layer of the print shedding? Leo? but its only once in a while. after 10 runs, its stops shedding.

Is this happening on every print you have???

Darren

Posted by Jason Burroughs (Member # 68) on 07-22-2003, 10:23 AM:

On the V-5's that I ran I had the exact same thing, never any noticable damage, either looking at the film, or on screen. Proper cleaning of the gates, and proper lubication helped, but was still there to some degree. I don't know about other V-5's but the gates that I had weren't the smoothest and had dips and ridges down the legnth of the rail. BTW I had straight gate V-5's not curved.

Posted by Gordon McLeod (Member # 33) on 07-22-2003, 11:44 AM:

My experience was that there was a pad roller closing a little tight and that caused powdering and the gate being hot tended to colect it