8mm Forum: ST1200HD Gate Jitter

This is topic ST1200HD Gate Jitter in forum 8mm Forum at 8mm Forum.

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Posted by Claus Harding (Member # 702) on September 13, 2008, 12:10 PM:

I have a second 1200 which is either going to get fixed or used for experiments. Right now, it transports ok, but there is a quick side-to-side jitter in the gate that shows on the screen. It varies a bit if I squeeze on the pressure plate, but doesn't go away.
And simple solutions? Or complex ones? [Roll Eyes]

Claus.

Posted by Tony Stucchio (Member # 519) on September 13, 2008, 03:57 PM:

Does that happen with all films? I get a slight side-to-side jitter on some films, but lubricating the film with Film Renew usually fixes it.

Posted by Claus Harding (Member # 702) on September 13, 2008, 06:00 PM:

Tony,

No, I tried different films and they exhibit the same look: fast jitter and also showing what looks like the right side of the gate in the picture. Something is out of whack. For some reason, it runs better in reverse; it almost eliminates the jitter.

So what? Pulldown trouble? Gate bent? Too little/too much tension on the pressure plate? I am open to ideas.

Claus.

Posted by Kevin Faulkner (Member # 6) on September 13, 2008, 06:54 PM:

Have seen this before on Elmo's and its usually down to the Claw being out of position so that it's hitting the edge of the sprocket.

If you lay some film in the gate with the gate open and hold it in place with your finger. Turn the mechanism with the knob on the front of the machine and see if the claw is hitting the edge of the film. It should not hit the sprocket at any point of its travel.

If you are seeing the edge of the film on screen it would suggest that someone in the in the past has moved the position of the fixed edge guide.

To set this up properly you really need to use an SMPTE test film however you may be able to set the position again by readjusting the edge guide but it's fiddly without a test film. Only adjust this part if you are sure the image is not correct on screen otherwise there are adjustments in the rear of the machine for adjusting the claw position.

Kev.

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