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Author Topic: ST-1200 chewing while threading
Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 12, 2014 01:38 PM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
Anyone know what to do to get the machine to thread without chewing like this?

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This was clean and newly cut before threading and comes out like this

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 12, 2014 01:45 PM      Profile for Andrew Woodcock         Edit/Delete Post 
Vidar there is no one single fault that causes this. There can be dozens of reasons as to why this would happen. It is all a case of process of elimination and logical thinking to narrow it down somewhat. Once you have been able to do this, then someone on here will no doubt have experienced the same on their machine.

I have to say, if I could find a decent SH30 for my optical prints, I would never want to see another Elmo in my living room in my lifetime based on past and present experiences.

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"C'mon Baggy..Get with the beat"

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Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 12, 2014 02:06 PM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
Well, I know it happens at the point where you thread the film ... It's before the gate and onto the first sprocket wheel. I was thinking, crooked path, but can't see anywhere to adjust anything

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003


 - posted December 12, 2014 02:08 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
Is this one film that this happens or all of them?

(process of elimination!)

If you look at the first couple of frames of an experienced print, you can usually see a shallow gouge where the sprocket teeth are hunting for a perf to drop into, but this looks like they tore into it.

Are all the teeth on that first sprocket in good shape?

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All I ask is a wide screen and a projector to light her by...

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Mathew James
Jedi Master Film Handler

Posts: 740
From: Hamilton, Ontario, Canada
Registered: Dec 2014


 - posted December 12, 2014 02:10 PM      Profile for Mathew James   Email Mathew James   Send New Private Message       Edit/Delete Post 
Interesting how it is basically starting at the left tip and chewing mostly on the left sprocket hole side.
If you happen to see it happening when you feed it in, is it happening on the first sprocket just past the auto-thread opening, or is this happening after the sound head when it goes to the underside sprocket?
My hunch i it i happening right at the start before you even get to the gate. I wonder if loosening the screw on that sprocket, re-centering the sprocket gear and retightening the screw would help. It can't hinder if it is already chewing, but i would obviously use an old reel you don't care about....
My St1200HDM, so far, is doing pretty good.... I haven't chewed any film yet but did have one time when the film, after passing the sound head, didn't go into the guide but found a way through but i caught it quick and reversed before any damage.
No matter how many positive experiences i have, i still seem to always keep the side open and watch, just in case because it just takes that one time to put me on edge.... [Smile]
Hope someone chimes in to help you!
Matt
EDIT: Vidar beat me to the post...but my comments may still apply.Cheers.

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Cheers,
Matt 📽

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 12, 2014 02:23 PM      Profile for Andrew Woodcock         Edit/Delete Post 
Are you using the half moon trimmer that you get with an Elmo Vidar?

2/ Is the theading shoe locking down as it should forming a very close coupled loop?

3/ Is there any wear or obstruction on your top guide shoe or other plastic threading parts?

4/ Are the two top rollers fitted around the top sprocket free of obstruction, free turning, correctly fitted and lubricated?

5/ is the top sprocket revolving freely and at the correct speed relative to the bottom sprocket but in the opposite direction?

Ask yourself all these questions Vidar by inspecting the relevant parts and dismantling where necessary and then you may be nearer to finding a solution hopefully.

either way by the looks of things your film is being ripped by the top sprocket one way or another so as it is at the very start of proceedings, it shouldn't be too difficult to spot hopefully.

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"C'mon Baggy..Get with the beat"

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Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 12, 2014 03:04 PM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
It's mostly all films (which all threads fine on my two other 1200's)

Using the Elmo trimmer and it looks fine. I will inspect the sprocket wheel for any damage.

Thanks, have something to check now. I am a bit scared something falls off and I don't know where it should sit. Would anything inside (on the back) fall off if I remove the whole sprocket wheel?

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003


 - posted December 12, 2014 03:17 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
I think the place to start is rotate the sprocket manually so you can give the teeth a good look. Maybe one is bent or broken.

If you can move the shutter wheel manually from the machine's right side, you might not even need to take the back off.

You can pull the sprocket off later if you need to. It's not that bad.

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All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 12, 2014 03:21 PM      Profile for Andrew Woodcock         Edit/Delete Post 
No my friend, feel free to take all the top sprocket parts off. No harm will be done and quite frankly this is one job that any ST1200 user needs to do quite regularly to lubricate the rollers and thoroughly clean the plastic parts. Just ensure you use decent instrumentation screwdrivers so as not to round any of the screw heads. That is the only real watch out along with ensuring the two tiny rollers are put back the right way around.

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"C'mon Baggy..Get with the beat"

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Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 12, 2014 04:17 PM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
I've replaced the sprocket wheel (the thin part only) with one from a projector without this problem. Didn't help. It seems the angle of the feeder is wrong ... Like the film hits straight onto the sprocket and not going under. I hear ugly noises when the film reaches the sprocket wheel. One out of ten times, it goes in without any noise. But I can't seem to find any way to adjust the angle of the feeder. It's on a metal piece with a long pin that it sits on and the metal piece is connected to the small metal clip (tension thingy) and I removed that and put it back on and it worked ... Once :-(

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 12, 2014 05:12 PM      Profile for Andrew Woodcock         Edit/Delete Post 
You are very good at the digital tech side of things it would seem Vidar. Try posting us a video so we can exactly see what's going on in there. remember a picture often tells more than a thousand words..

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"C'mon Baggy..Get with the beat"

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Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 12, 2014 05:21 PM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
Will try that tomorrow. Thanks for all suggestions

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Tom Photiou
Film God

Posts: 4837
From: Plymouth U.K
Registered: Dec 2003


 - posted December 13, 2014 05:24 AM      Profile for Tom Photiou     Send New Private Message       Edit/Delete Post 
Vidar, if it was me I would remove the top sprocket together with the whole top green guide and clean it all up and take a good look, make sure the screw that holds that toothed ring to the sprocket is tight and hasn't worked loose, all the little rollers are free to spin, get it back together and try again.
If you want me to scan and e mail you the exploded diagram let me know. Unless someone already has a file they can load onto here for you. [Wink]

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Barry Fritz
Phenomenal Film Handler

Posts: 1061
From: Burnsville, MN, USA
Registered: Dec 2009


 - posted December 15, 2014 11:44 PM      Profile for Barry Fritz   Email Barry Fritz   Send New Private Message       Edit/Delete Post 
Is the auto thread lever staying locked down when you are feeding the film?

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 16, 2014 12:06 AM      Profile for Andrew Woodcock         Edit/Delete Post 
Barry, quetion 2 that I put to Vidar was whether or not the threading shoe was locking down.

As Vidars machine cannot get beyond the first sprocket without chewing the sprocket holes on the film, it cannot be that the shoe or "auto lever" as you are naming it, can be sticking in the downward position because this would only cause a problem once the film has made it to the take up reel and has not released the shoe as the electro mechanical mechanism should.

At the point where the machine is chewing film, ie the top sprocket, you want the shoe to be in the lowered position so it will thread correctly.

Unfortunately, in Vidar's case, this isn't happening as it should, but from what he describes, the shoe is at least going downward into it's correct locked threading position.

[ December 16, 2014, 02:44 AM: Message edited by: Andrew Woodcock ]

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"C'mon Baggy..Get with the beat"

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Vidar Olavesen
Film God

Posts: 2232
From: Sarpsborg, Norway
Registered: Nov 2012


 - posted December 16, 2014 04:19 AM      Profile for Vidar Olavesen   Author's Homepage     Send New Private Message       Edit/Delete Post 
That is correct. Everything works fine when it gets past the place the film gets "hooked" onto the sprocket gear. It seems to be pointing directly 90 degrees onto the gear, while I would assume it should have a little angle. Can not find anything to adjust on it. Will try the suggestion of removing it all, clean and re-assmeble but need some time for it. So worried something else will fail, as I am totally useless at these things

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012


 - posted December 16, 2014 04:28 AM      Profile for Andrew Woodcock         Edit/Delete Post 
Surely one of your many film collecting friends or maybe your Son could step in here Vidar if you don't like to take on the task yourself?

I am sure it would reveal something if you were to dismantle the top sprocket and guides, there is very little to be wrong apart from wear or blockage to guides or maybe damaged to the teeth on the sprocket perhaps.

The initial guide does have a location peg as well as a screw to hold to the body of the machine, maybe the location peg is not sat in it's location hole if the guide appears to be at an incorrect angle? It should sit dead square to the frame.

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"C'mon Baggy..Get with the beat"

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Paul Browning
Phenomenal Film Handler

Posts: 1006
From: West Midlands United Kingdom
Registered: Aug 2011


 - posted December 16, 2014 04:58 AM      Profile for Paul Browning   Email Paul Browning   Send New Private Message       Edit/Delete Post 
Vidar, the top guide wears flats on it very close to the top sprocket, maybe this has developed a lip on it and is not allowing the film to flex enough to lace correctly, it is quite easy to remove a get a look at, this has been modified on my machine, and now has a roller fitted to stop scratching the film and aid transit through this auto loading mechanism.

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Barry Fritz
Phenomenal Film Handler

Posts: 1061
From: Burnsville, MN, USA
Registered: Dec 2009


 - posted December 17, 2014 11:40 PM      Profile for Barry Fritz   Email Barry Fritz   Send New Private Message       Edit/Delete Post 
Thanks Andrew. I missed your earlier question. I do understand the function of the lever. I asked because I have seen on some machines that the shoe (lever) does not stay down as it should. Due to wear or age or whatever reason, it does not lock down or may lock down initially but then pops up sooner than it should.

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