8mm Forum: Elmo GS 1200- dangerous part

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Posted by Heinrich Kronschlaeger (Member # 145) on January 11, 2004, 05:03 AM:

Hi,
I had sent the dangerous plastic piece on the loading path to Mr. Mangold in Germany to modify it ( to avoid scratches on the film ) . If you send that plastic part to Wittner, Wittner sends it to Mr. Mangold , this man does that job.
But I have noticed that there is another dangerous plastic part on the GS 1200 . You have to press that part when loading the film at the beginning of projecting ( That piece is above the first gear drive ). When the film gets out of the channel it touches that plastic part ( with the side of the film on which the sound stripes are placed ) . That part will be abraded by the film and the result will be scratches on the film.
How can I avoid that the film touches that part ?
Kind regards
Henry

Posted by Ugo Grassi (Member # 139) on January 11, 2004, 05:30 AM:

Yes, this is correct. You have to glue two "teflon" thin strips on the edges, where the film runs.
An other dangerous place is around the plastic pins for rec/play heads. When the "foots" of the pins for the main stripe are consumed, the pin begans to run over the frame, and on the screen (right side) appears a scratches.
To avoid it you have to disassemble the black cube where are the pins (they are 4, two for channel), and to reduce the "footprint" cutting the pin by a razor blade.
Just for curiosty: how many do you pay to Mr. Mangold to modify that plastic piece?
I spend 30 minutes to modify it. Next time send the piece to me; I'll do this work without payment.
It's a light work!

[ January 11, 2004, 12:27 PM: Message edited by: Ugo Grassi ]

Posted by Heinrich Kronschlaeger (Member # 145) on January 11, 2004, 09:51 AM:

Thanks Ugo for your hot tips !
I phoned Mr. Mangold a few months before . I think , he is a very serious man . For modifying the piece I have paid 40 Eur
What " teflon stripe " do you glue on that part I discribed ?
Bye
Henry

Posted by Alan Gouger (Member # 31) on January 11, 2004, 10:27 AM:

This is very informative information. I had no previous knowledge of any of this.
Please keep any tweaks/fixs/modifications coming. It would be nice to have one thread dedicated to this.

Thanks!

Posted by Ugo Grassi (Member # 139) on January 11, 2004, 11:00 AM:

I think I'll get some photos of the modifications I made on my GS to publish it here.

Posted by Kevin Faulkner (Member # 6) on January 11, 2004, 06:48 PM:

Sorry Ugo but I disagree with you about this being a dangerous part. If you get wear on the entrance of the loop former which is the part you are talking about then the position of the sprockets in relationship to the film claw is not adjusted very well.
In normal projection the film should not touch the loop former at all. If it does then you can stop it doing so by undoing the screw which is in the centre of the 1st sprocket wheel and then turning the sprocket teeth by half a frame clockwise which will shorten the loop. Hope that makes sense. What I am saying in reality is that the top loop is slightly too big. The only time the film should ever touch that loop former guide is when it is pressed down for threading.
If the film touches the loopformer during projection it will generate noise and will be even noisier during threading which was a complaint that Tony had on an St600. You will probably also notice a slight bounce movement of the guide if the film is touching it during projection.
Hope that helps you guys and aleviates the need for sticking anything in the guide which will reduce the tolerances even further. Just think get a bit of muck stuck on your teflon coating and your film WILL get SCRATCHED [Frown]

Properly adjusted and it does not wear and will not scratch film. [Smile]

Just remembered to asy that it is still possible to buy the replacement lack plastick pins or head pressers ans Elmo call them. Try Wittners in Germany I got a whole new presser assay from them and other sources have them too. Kev. [Smile]

Posted by Ugo Grassi (Member # 139) on January 12, 2004, 03:28 AM:

Hi Kev,
I agree with you, but I was talking about an other point of wear.
The loading path is composed by two part: one is mobile (it's able to former to loop; the other is fixed to the projector body. Bottom this there is the plastic guide modified by Mr. Mangold.
Well. Over the sprockets there is a little point of contact. It's necessary to bring the film into the teeth of the sprockets.
Of course after this point the film doesn't touch anymore the loop former, otherwise this former would "shake", and big noise would arrive from it.
I put the teflon stripes in corrispondence of the contact point, and for the edges of the film only.

Posted by Kevin Faulkner (Member # 6) on January 12, 2004, 05:41 PM:

Thats just the point Ugo. The film can touch that point on the former and does if the adjustment of the 1st sprocket wheel is incorrect. I do agree with you about the point on the top sprocket guide where the film exits that point. In the UK here Keith Wilton cuts that point away and inserts one of the white plastic rollers so that it then resembles the sprocket shoe on the ST1200. I am interested on the thin strips of Teflon you use. Where do you source this stuff from and what glue do you use to fix it in place.
I did mention to you in an email that a lot of people overlook the small black plastic tensioner just in front of the second sprocket. It's used to cut down wow on the sound. How many people ever run their finger under that tensioner to see if its worn. It should feel curved and not have any flats on it. If it gets flats worn into it, it will scratch the base side of the film well into the picture area eventually. [Frown]

Ugo, I can just see every one opening their GS's now and feeling that tensioner.
How do you sort it? Remove it (noting the spring adjustment position) and file it back to its curved shape and then polish it. The film should only touch this item on the extreme edegs of the film. Nowhere into the film area.

Kev.

Posted by Heinrich Kronschlaeger (Member # 145) on January 13, 2004, 11:43 AM:

Hi,
In my GS 1200 ( vers 2 ) the head pressers are made of grey metal, they seem to be better as plastic pins. Why has Elmo changed it to plastic pins in the vers 3 ?
Another thing Elmo changed :
The pressure plate at the gate area was built very well in the vers 1 . In the vers 2 and 3 the metal was manufactured more thinly, so that the 2 rivet heads are standing out of the metal a little ( in the film channel !! ) . Dangerous for an old curved film. I think most dangerous is the rivet at the bottom, especially if the filmloop runs to the left ( vers 3 ).
Kevin, the black plastic tensioner in front of the 2nd sprocked seems to be a plastic of higher quality as the green plastic parts for threading.
Bye
Henry

Posted by Ugo Grassi (Member # 139) on January 13, 2004, 12:30 PM:

Hi Kev.
If I right understood, the film have to touch NEVER the mobile loop former? Or is it possible the film touches that mobile part where you putted the blue arrow?
mmmhhh... so probably, with the film loaded,I have to unscrew the central screw of the first sprocket and to move the teeth-ring until the film doesn't touch the mobile part. Right?
With this solution I have not to modify the loop former, because the film doesn't wear it.
In Italy we say: this is a "Colombo's egg"! Solution simple but brilliant!

Posted by Mike Peckham (Member # 16) on January 13, 2004, 01:30 PM:

Kev'. What about if the film touches that top loop forming lever every once in a while? Mine seems to work perfectly 99% of the time but every once in a while, possibly when a bad splice goes through or even from the very beginning of a film, that top guide starts rattling just as you describe and it is evident that the film is just touching it. Sometimes pressing the loop lever sorts it out but sometimes not in which case the only solution is to hold it up until the film finishes [Frown]

. Does this mean that it needs adjusting?

Mike

Posted by Kevin Faulkner (Member # 6) on January 14, 2004, 09:20 AM:

Yes Ugo, with that little adjustment the film should never touch and you wont get wear in the loop former. Simple adjustment but effective. An elmo engineer gave me that little tip many years ago. Shame it wasnt put in the setup procedure in the service manuals.
Mike, if your film loop gets bigger and touches the loop former during projection then it means the film has slipped up the gate by a frame when the splice went through. I cant say anymore other than to check your splices. The only way this will happen is if the splice is too bulky and has pushed the presure plate open enough to let the film slip or the presure plate's tension is not great enough. One other thing but not too likely is that the claw is not proturding enough into the sprocket holes. You can check this by running the machine in forward still until you have the claw at max protrusion. It should stick out from the gate by 1mm. Too little and you will get film slip when there is a disturbance such as a splice, too great and the rear of the claws can hit the film making it very noisy and with possible picture judder. [Frown]

Check those splices first mate [Wink]

Heinrich, I have presure plates from various machines and they are all identcal. The same part number has been used for all the Elmo machines. I have never seen one which is thinner. Maybe you found an odd one which Elmo had tried in production at some time or other.
The black plastic tensioners do wear quite badly. Just because they are black Nylon instead of Green whatever dont take it for granted that they wont wear. You will find out to your cost that they do. If the green input guide has wear on a machine you can bet that the black tensioner will too. [Frown]

Kev.

Posted by Ugo Grassi (Member # 139) on January 14, 2004, 12:56 PM:

At first: Kev. is a genius!!!
Second: here the photo of one of my light works to avoid scratches from my Elmo GS.

No... sorry, the administrator doesn't give the permission!
I want the picture appears in the post! Anyway I follow this easier way:

http://gallery.avsforum.com/data/509/2PICT0006.jpg

look before the first roller, and the little black plastic tensioner just before the second sprocket. There are the little teflon guides I use to avoid scratches.

[ January 15, 2004, 01:24 PM: Message edited by: Ugo Grassi ]

Posted by Alan Gouger (Member # 31) on January 14, 2004, 02:59 PM:

Ugo you have mail:)

Posted by Ugo Grassi (Member # 139) on January 15, 2004, 03:21 PM:

Hi Kev.
now I'm at home. I'm trying to adjust the first sprocket of my Elmo like you said. I unscrew the sprocket and, with the film loaded, I adjust the position of the teeth-ring until the film doesn't touch the loop former. But there is a "but". When I reload the film, it gains the old position (touching the loop former). What's wrong?

Posted by Ugo Grassi (Member # 139) on January 18, 2004, 12:40 PM:

Here the pictures of some my little works to avoid scratches to my films:

http://www.8mm.filmshooting.com/scripts/gallery/super8projectors/PICT0033

http://www.8mm.filmshooting.com/scripts/gallery/super8projectors/PICT0046

http://www.8mm.filmshooting.com/scripts/gallery/super8projectors/PICT0035

http://www.8mm.filmshooting.com/scripts/gallery/super8projectors/PICT0044

Posted by Kevin Faulkner (Member # 6) on January 21, 2004, 04:42 AM:

Hi Ugo,
You are turning it too much each time. It only needs to be moved by no more than the distance between two teeth. Normally about 1/2 the distance.
Hope that helps. Kev.

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