Elmo GS1200 image unstable problem

[Patrick Steemers]

Hi dear Super8mm lovers!
I have this issue with my Elmo GS1200 that the image is quite unstable.
it started with primarily ‘left-to-right’ shifting of the image every say 1 minute or so, quite intermittently.
I read the service manual and took out the spring wire that’s visible what you swing out the lens. I turned it round and bent it a bit and the left to right seems a lot less.

But there’s also a considerable up and down movement of the image. Not like a stutter but more an unsteady swaying up and down.
I have a hunch it has to do with the framer but not sure yet.

anyone has any experience with this? Or who has (had) same problem?

thanks in advance!

[Stuart Budd]

I don't know but I'll help guess. It's not top loop as you appear to see an image. Left right has improved. Just the parked projected frame isn't in sync image wise with the previous one. Frame is mechanical making I think. So is takeup tension right. Having said that, there are sprockets before and after gate so reel tension probably isn't an issue. But I'd probably run an unspooled length of film through just to see.
Having done that, I'd test your thoughts by adjusting frame then holding frame by taking up any slack with a slightly anticlockwise twist.
Hopefully it's a known issue and the real solution will follow 👍

[Paul Adsett]

Try adjusting the fixed edge guide (2 screws) in the gate very slightly in or out to center the film sprockets on the claw pins. This is a trial and error adjustment requiring patience and persistance, but if you get it right the picture should be rock steady.

[Larry Arpin]

Are you projecting acetate or mylar/estar? I've had this problem also with acetate and after making adjustments to the side by side adjustment and the lower film tensioner, it was too tight, and applied some film guard and it was much better.

[Patrick Steemers]

I don't know but I'll help guess. It's not top loop as you appear to see an image. Left right has improved. Just the parked projected frame isn't in sync image wise with the previous one. Frame is mechanical making I think. So is takeup tension right. Having said that, there are sprockets before and after gate so reel tension probably isn't an issue. But I'd probably run an unspooled length of film through just to see.
Having done that, I'd test your thoughts by adjusting frame then holding frame by taking up any slack with a slightly anticlockwise twist.
Hopefully it's a known issue and the real solution will follow 👍

thanks for your thoughts!

[Patrick Steemers]

Try adjusting the fixed edge guide (2 screws) in the gate very slightly in or out to center the film sprockets on the claw pins. This is a trial and error adjustment requiring patience and persistance, but if you get it right the picture should be rock steady.

Is this the guid that you can see when you sway the lens outward and you look upon the film and then it’s the one without the spring? The left one if you look at it?

[Paul Adsett]

Is this the guide that you can see when you sway the lens outward and you look upon the film and then it’s the one without the spring? The left one if you look at it?

That's correct Patrick. You need to loosen the screws just a bit, just enough to retain the plate in position, and then move it very slightly in or out to get a steady image.

[Patrick Steemers]

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That's correct Patrick. You need to loosen the screws just a bit, just enough to retain the plate in position, and then move it very slightly in or out to get a steady image.

Should the plate with the spring be pushed to the right a bit so that the film is kept in between the two plates with a bit of pressure of that spring? Or should that spring-enabled plate not be pushed at all when the film is in between the plates?

And would it help to adjust that plate that is fixed to the lens mount?

thanks again!

Patrick.

[Paul Adsett]

Yes, the moveable plate with the wire spring attached should be pushed slightly to the right so that the film is always being pushed into the edge of the fixed left guide .
No need to mess around with the gate pressure plate attached to the lens mount.

[Thomas Knappstein]

The Problem of an unstable Picture is most worn out Side Guides and worn out Calw Tip.
And low pressure of the Springs on the pressing Plate of the Optic Holder.
This Springs must have 65 Gramm and the Side Guide Spring must have 40 Gramm.

Never lose the Screws of the left Side Guide and move this Part. If you do this, the Picture Frame is getting out of Center and the Calw Tip is getting out of his right Position.

What I do is take the complete Aperture Plate with both Side Guides out of the machine and disassemble both Side Guides from the Plate.
Then I refresh this Side Guides and adjust the Left one with a special Film, so that the Image is in Center of the Frame. Then assembling the Plate back into the machine, in the same Position it has before took it out. This is a very dificult Procedure and you shouldn´t do this if you have never done things like that. I do this for 30 Years now and I know what I do.

If the Calw Tip is worn out you need a complete new Calw. Wittners in Germany has one for the ST1200 you can use in the GS1200 too. But he will 150Euros for this little Part.

On the Picture you can see how deep the Film has worn in the Side Guide of an Elmo Plate. This is a refreshed Guide because the worn Slots are above the Plate, where the Film is running.

[Stuart Budd]

Amazing the information a close up can give! What sort of hours would do that? Is it a home machine or events and rental type! Something to inspect prior to a purchase. Really does seem prudent to view and if possible, know a machines history (as has already been advised) before the plunge! I'm beginning to feel like the girl at the start of Jaws! Instead of being dragged about by a shark, I'm falling over disassembled projectors! I know where I'd prefer to be though. Shark! I mean projectors, projectors

[Thomas Knappstein]

Hi Stuart, I don´t know how much Hours are on this machine. I bought in the late 80´s 5 ST1200 from a sex Cinema for spare Parts. I think this Guide is from
one of them. With my oldest GS bought in 1991 this guides are ok today. I think It must be over 1000 Hours that it will be look like on my Photo.

[Mark Norton]

Bit of a bodge, but bending in the side guides so the film can't go in the worn grooves works.

[Oliver Feld]

I had this „shifting“ problem on my Elmo gs 800. But the issue disappeared when I used Filmguard to clean the films before (or while) projection. This only happened to acetate prints. Then the image was stable. Is it maybe only that, Patrick?

[Patrick Steemers]

I had this „shifting“ problem on my Elmo gs 800. But the issue disappeared when I used Filmguard to clean the films before (or while) projection. This only happened to acetate prints. Then the image was stable. Is it maybe only that, Patrick?

It might very well be because it happens with some films and not with some others.