Film-Tech Forum ARCHIVE: Frame not stable on screen shaky image

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Posted by Michael Moore (Member # 3867) on 05-02-2007, 06:38 PM:

Frame not stable on screen shaky image

I am new to this forum, however I have been projecting film for on and off for the past 10 years or so. I am currently head projectionist at the Schwartz Center for the Arts in dover Delaware.
We are running are films on a super simplex with a Speco LP 270 platter. I had to recently replace my intermittent as well as several of the fiber gears because the intermittent star gear cracked during a show.
I now have a new problem I never had before. The image is shaky on the screen, and it seems to be worse on some movies then others. I have tried to increase tension on the springs behind the pads but this did not help. I tried the use a different film gate al together but this does not solve the problem. At some point we are getting a grant to replace the super with a century. Until that day arrives I have to live with what I have. Does anyone have any tricks to fix a problem like this?
Thank you
Mike

Posted by Mark Gulbrandsen (Member # 72) on 05-02-2007, 06:50 PM:

Michael... we really need more specific info...

Is the image shaky up and down or side to side or both?

Was this shake concurrent with the installation of the new intermittent?

Are all the gears meshed properly and did you check to see if any of the shafts were bent before replacing the gears?

The Super is no slouch in spite of its age... I'd put up a well running Super any day against any projector out there.

Also... "May the Schwartz be with you"... I just had to say that!

Mark

Posted by Tim Reed (Member # 137) on 05-02-2007, 08:50 PM:

Maybe I'm reading you wrong, but it sounds like you replaced the starwheel?! That operation requires high-precision parts, procedures, and adjustments. If you replaced the entire movement with a spare, however, it could be that it was bad to begin with.

Is the intermittent sprocket secure on the shaft? Does it have even the least little play while in the dwell position? (Oh, and make sure there's enough oil in the intermittent casing... maybe that goes without saying, but you did say you've been on and off [Wink]

.)

I would look to the intermittent as the source of the image unsteadiness, rather than the gate.

Posted by Mark Gulbrandsen (Member # 72) on 05-02-2007, 09:04 PM:

quote: Michael Moore
I had to recently replace my intermittent as well as several of the fiber gears because the intermittent star gear cracked during a show.

Tim,
Somehow I derived from his post that he replaced the intermittent and some of the fibre gears.... I don't see that he replaced the starwheel itself.

MArk

Posted by Michael Moore (Member # 3867) on 05-02-2007, 11:06 PM:

The shakiness is up and down no side to side.

I did not replace the star gear. I discovered the star gear was destroyed after taking the intermittent apart. I'm a machinist by hobby and partially by trade, I have more then enough tools to overhaul a projector and make parts as well, however I have never replaced just the star gear I'm sure I can; but I never needed to so never tried.

I checked the shafts they are all strait. All gears mesh well. The intermittent moves very smooth. I religiously oil and recheck oil every time I show a movie. I project every Wednesday, and Sunday. Fridays are my cleaning and maintenance day.

The intermittent I replaced it with was one we had in a box. It was sold to us as "refurbished" about 4 years ago. I replaced the fiber gears with ones from our spare projector head we have. It could be the intermittent I guess. I have another intermittent that came out of the other projector head a while back. I put it in a box for safe keeping. Maybe I can replace it with that one to compare?

The film I projected tonight was really bad. I projected Venus, Last week I projected The Queen and it was not as bad.

I also noticed that reel two was the least shaky and reel 6 was the worst. Credits were really telling of how shaky the image is. I suspect this is because credits are words and they are moving up
May the Schwartz be with you too

[ 05-03-2007, 11:34 AM: Message edited by: Michael Moore ]

Posted by Louis Bornwasser (Member # 3063) on 05-03-2007, 03:10 AM:

I agree that the Super is more than the equal of most new projectors. Howevedr, in the interest of expediency and also reducing oil usage, I would use this as an "excuse" to go ahead with the Century.

Beautifully rebuilt ones are commonplace if you are careful. Louis

Posted by Monte L Fullmer (Member # 2797) on 05-03-2007, 03:44 AM:

Gate tension? Have to remember that polyester stock is a shade thinner than the acetate stock so that gate tension might have to be increased a bit esp with good ol SuperSimplex units...and that is the shoe tension spring in as well as the gate tension springs.

Yea' doing an intermittent rebuild on a Super was my first time I did a rebuild on any projector..and learning about taper pin usage...at 23yrs old (intermittent sprocket was hooking badly...). After the rebuild, that Super ran tons more smoothly-not bad for a first timer. - Monte

Posted by Michael Moore (Member # 3867) on 05-03-2007, 07:40 AM:

What I am going to do is adjust the pad tension again, the shoe tension was not readjusted when I did this last. In fact I never changed it when I installed the newer intermittent, this might be the issue. I will check that out tomorrow when I clean.
Let you guys know what happens.

Mike

Posted by Mark Gulbrandsen (Member # 72) on 05-03-2007, 08:23 AM:

It has to be a bad intermittent!! Don't waste time adjusting things on this one until you've tried another movement. If you need one let me know. We have a couple of boxes full of them and a couple dozen complete Supers in the basement to rob from. BTW: I know that grants take a looooong tome to aquire so you may have to fix this one again...

Mark

Posted by Tim Reed (Member # 137) on 05-03-2007, 10:04 AM:

quote: Mark Gulbrandsen
I don't see that he replaced the starwheel itself.

Mark, he said the star had cracked, so:

He had to have had the movement apart to know this.
He said he was "on and off" in the booth.
He said there was now lots of unsteadiness in the picture.
In the vernacular of someone unfamiliar with certain terms, "replace intermittent" could mean replace the defective part, since...
Lots of old booths had spare stars and cams in the parts cabinet...

You tell me. [Wink]

Posted by Tim Reed (Member # 137) on 05-03-2007, 10:04 AM:

geez!

Posted by Michael Moore (Member # 3867) on 05-03-2007, 10:24 AM:

First I am in the booth about three times a week sometime four.
I have been keeping this schedule for about 4 years now; I got back into projection when the Schwartz Center was renovated. Before that last time I was in a booth was about 2 years before.

Second when projector broke I was not in the booth, my assistant was projecting, and I was in Florida for Radiation Safety Training so I did not see what happen.

Third when I returned I had to troubleshoot why the fiber gears were striped. Intermittent did not rotate at all, so I thought that was the problem. It was suspect so I removed it. I did not disassemble it at first; I replaced the entire intermittent assay not the starwheel with a refurbished intermittent as well as the gears.

Fourth I then tinkered with the seized up intermittent to see why it was in this state. Disassembled and discovered the starwheel was cracked. This was the newer style starwheel; I could tell because the sprocket was attached to the shaft via a single bolt and nut not the two tapered pins.

I have an additional intermittent that was not working well from the spare projector head and I want to try it out.

I may take you guys up on the other intermittent you offered if I can't get the other one to work.

But you guys think it’s the intermittent and not the gate?
Mike

Posted by Mark Gulbrandsen (Member # 72) on 05-03-2007, 10:28 AM:

Tim...

I just have to rub it in [Razz]

. Its pretty plain that he said he replaced the intermittent. I don't see any vernaculars coming into play in that line. Now lets take NASA for instance... When they say they launched the space shuttle they HAVE launched it... they didn't just replace the LH2 turbopump on one of the rocket engines and then test fire it. His line as copied over from above is quite literal..."I had to recently replace my intermittent as well as several of the fiber gears because the intermittent star gear cracked during a show."

Does it say he replaced the star in that line? It just says he knows the star cracked during a show... BUT... it does say he replaced some of the fibre gears... quite common to have to do when just about any movement piles up!

Am still trying to figure out what on and off in the booth has to do with any of this.... This is about picture bounce not on and off projection work as many of the projectionists out there seem to do. What I am offering is to send him a good movement if he decides to take me up on it.

May the Schwartz also be with you [thumbsup]

.

Mark

Posted by Jack Ondracek (Member # 1466) on 05-03-2007, 10:55 AM:

Now boyz.... [Roll Eyes]

Posted by Michael Moore (Member # 3867) on 05-03-2007, 11:21 AM:

All of this aside about on and off in the booth, and what I replaced
I want to test out the intermittent I have and see what goes on; then if that does not fix it then I'm going to take you up on the intermittent movement you have to offer; Mark.

I think I can get in and change that intermittent out Saturday evening and fool with it.
Mark, I’ll keep you posted as to what happens.
Mike [thumbsup]

Posted by Tim Reed (Member # 137) on 05-03-2007, 10:22 PM:

Mike and Jack: it's okay. Mark and I's just ribbing each other. [Wink]

Posted by Michael Moore (Member # 3867) on 05-06-2007, 05:58 PM:

OK; I got a chance to try out that other intermittent. It is a no go, the intermittent sprocket wobbles so the stargear shaft must be slightly bent. I reinstalled the other intermittent movement and watched the movement for a while. I could see it had some play (up and down). I then stopped the projector, turned it over by hand to get the intermittent in the dwell period, held the end of the stargear shaft, and the intermittent sprocket when pushed had some play. So apparently, it is not attached to the shaft properly. As soon as I'm done tonights showing I'm going to take out the intermittent, take it home, remove the tapered pins, and install some new ones. I think this will take care of the problem. Any thought from you guys? Do any of you agree that this might be what's causing the issue? If so it is my first experience with this kind of unstable image. I also have a slight ghosting problem I'm unable to overcome and I think it is from this lose intermittent sprocket problem. If this dose not work then I'm going to definitely take Mark up on his offer. [Frown]

I've got to add this. I just got done projecting letters from Iwo Jima and the picture did not shake nearly as much as Venus did last week. However the ghosting at the bottom of the screed is still there. I have tried everything to stop this ghosting problem to no avail.

[Confused]

[ 05-06-2007, 08:05 PM: Message edited by: Michael Moore ]

Posted by Michael Moore (Member # 3867) on 05-07-2007, 07:53 AM:

update: I know the rules says not to keep posting after your last post but to edit your previous, however, this a partial solution to the problems.

I fixed the travel ghost problem, took a while but it is much much better. Slight ghosting at bottom still on subtitles but nothing major. I don't like it, but I need to live with it till i can get a new intermittent.

Also I notice that when a splice goes through the gate, the gate moves out a little, and does not return back. I also notice that the gate has to be pushed in about a 1/16 inch extra every time I thread to close it all the way, it is as if there is something that is binding just a little but I have yet to discover it. I think this is compounding the issue even more.

any thoughts would be great.

Mike