GS1200 sideways judder

[Rob Young]

Looking closely that lower adjustment screw on the fixed gate alignment seems to have a slightly worn head...like it's been adjusted in the past.

Clive, would it be an idea to post the exact same image with the leader in your GS1200 Xenon?

[Mark Norton]

That little cone shaped eccentric where the film exits the gate should be in contact with the edge of of the film.

[Clive Carmock]

Thanks Rob - I'd say about 30% of prints I run on this one have sideways judder. I will certainly try filmguard as I have a couple of bottles of that here.
I wonder if the spring tension is too weak on the pressure plate opposite the sprockets

[Rob Young]

Clive, yes that claw looks pretty well aligned. But if the problem prints run ok in your other machine, then something must be amiss. This is where you really need a qualified engineer to make finite adjustments. Sadly, there aren't many left unless someone has a recommendation.

I wonder how many prints are causing you a problem with the one machine?

I would still try cleaning them with Filmguard as this can often perform miracles!!

[David Baker]

Yes and then at that point it's time to use the sledgehammer on it .

[Nantawat Kittiwarakul]

And be reminded to account for film shrinkage as well. After some 20-30 odd years its acetate base would probably had shrunken down somewhat. Not to the unprojectable point, but just enough to start causing some issues in certain projectors.

[Clive Carmock]

I have attached two pictures, one was intending to show the claw condition, but it doesn't really do that well. I don't feel a ridge in the underside of the claw though.

When loading a pice of white leader into the gate The lower claw appears perfectly centred, but the upper claw slightly to one side. From looking at the service manual this is not unexpected. Judging from these pictures I'd say the claw position looks reasonably good.

[Rob Young]

Steven makes a very good point. I've had prints that exhibit this side to side vibration on my Elmo ST but not at all on my Beaulieu. A clean with Filmguard does indeed help with some prints.

[Clive Carmock]

Thank you for this - really useful. I'll try to get some good pictures of the claw tip and pressure pads to see if they look to be worn

[Thomas Knappstein]

Thank you Maurice!
On the Sides 19-23 you can see the worn Parts.

[Maurice Leakey]

Here is the service manual of the GS-1200 for anyone interested:-
GS1200SERVICE.pdf (film-tech.com)

[Thomas Knappstein]

I have five GS1200´s in use. All restored and new adjusted in Calw and Filmway Area by myself.
I also have a few Prints who has this side by side moving. But most it is only one or two Reels of a full length feature.
So I think if the Knife from the splittig Process was worn out, the Film edge on the Sprocket hole side is not in order and the Film begin to move.
If you have a GS 1200 where the side Guides are worn from the film edge it can be that the Film has not enough pressure from the movable side guide and this failure doesn´t came up on this machine. Another Reason is a worn Calw Tip. This can make an unstable Picture too.

Take a look into the Elmo GS 1200 Service Manual. There are Pictures of worn Side Guides and Calw Tips.

This machines are 35 to 40 Years old now. They had a lot of running in the Prime Time of Super 8 Home Movies so today every GS 1200 need a refreshing for a second life.

[Steven J. Kirk]

Also consider dryness of the film edges. I have had this with 16mm and the solution was putting the film on a split reel to wipe FilmGuard on a cloth on the sides of the film. With super 8 treat between the spokes to get to the edges. Might help. Try it before taking the machine apart I would.

[Clive Carmock]

Hi Rob - thanks for following up on my post. We are thinking the same - I did use some cotton buds soaked in alcohol and cleared both the fixed and movable guides. I did wonder if it was the claw catching on the sprocket holes.

I am guessing alignment tools for these machines will be impossible to get now. Can it be done without do you know?

[Rob Young]

Just a thought, but try getting some cotton buds right into the 4 gate guides, the fixed and flexible on both sides of the gate, just to make sure that they are both immaculately clean.