Film-Tech Forum ARCHIVE: Century gate problem

This is topic Century gate problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by John T. Hendrickson, Jr (Member # 849) on 11-29-2003, 04:03 PM:

Just returned home from the matinee and I have a gate problem with one of my Century SA projectors. When you turn the knob to open the gate, it only advances about a half inch and will not stay open. It is threadable, but very tight.

I'm thinking it's the spring that's shot, but could it be more than that?

Second question: I have an old Westrex head and the knob appears to be exactly the same as the Century. Can I canabalize the spring and fix the problem? I hesitate to do this on a weekend as long as we can still thread and run.

Comments appreciated.

Posted by John Westlund (Member # 913) on 11-29-2003, 04:22 PM:

I have had that knob become loose and cause the gate not to open up all the way. It may have come loose and caused the spring to pop out. I would try removing the knob and checking the spring. Be careful when you remove it because that spring can go flying across the booth. You will be able to see that the spring fits into a hole in the knob and another one that is in the projector. Align the spring to both holes and turn the know until it seats all the way down. The screw wont tighten up until the knob goes all the way down. I hope this is of help to you. Im not sure about swapping those parts from the Westrex but im sure someone on the forum will have that information.

Posted by John Walsh (Member # 168) on 11-29-2003, 04:26 PM:

I had a problem like that.. turned out a lot of gunk had gotten in around the finished surface of that gate "tube." I sprayed just a little WD40, just enough for some to dribble around the tube, and then it worked OK. When I had time later, I just disassembled and cleaned it - which is a drag since disassembling it messes up the gate/trap alignment.

The spring is certainly another possibility; at least it's fairly easy to get at. Don't know if the Westrex parts are the same.

Posted by Mark Gulbrandsen (Member # 72) on 11-29-2003, 04:58 PM:

Best to disassemble it when time permits and do a through cleaning of the gate tube and other parts. Inspect the spring at that time. The spring is a bit tricky to replace/adjust if its your first time [Eek!]

. I suggest following the part in the manual on how to do that replacement. The SA manual is in the manuals section.

Gate alignment is not at all tricky but have a piece of drill rod or a drill bit of the correct diameter, I believe .25", so you can get the alignment perfect again in short time. Place the drill rod between the flat part of the gate plate and the side studio guide, push the lens tube assy against the drill rod and then tighten down the four mounting screws [thumbsup]

.

Mark

Posted by Michael Rourke (Member # 1142) on 11-29-2003, 05:07 PM:

It is probably the spring, but I have had the catch pin in the gate knob get burrs on it that prevented it from going into the hole to hold the gate open. I would just replace the whole knob assembly by removing the little allen head screws above and below the knob assembly. That way you can open up the knob and see what the problem is, replace the spring (which is tricky like Mark indicated) and not have to be in a rush to get the knob back together before your next show.

Posted by John T. Hendrickson, Jr (Member # 849) on 12-03-2003, 04:03 PM:

The problem is solved. The spring was fine. When I removed the gate tube I found the problem. One of the screws on the inner part of the tube had worked its way loose and was preventing the gate from opening all the way. [Eek!]

While I had the assembly out I took the time to clean it, but actually it was in very good shape.

Got everything back together and aligned correctly. Mark, you were right- that damn spring is an adventure in itself. [Roll Eyes]

Thanks to all for the help. [thumbsup]