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Topic: More GS Trouble

Brian Hendel
Jedi Master Film Handler

Posts: 902
From: New York, New York
Registered: Jun 2003

posted October 14, 2006 06:35 AM

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I sent my GS1200 in for repair twice over the last couple weeks and am still having trouble. First off, a spring came loose probably during shipping and I can't figure out where it goes maybe someone can look at there's and tell me. It's a small spring at the bottom of the projector - right below the plastic path the film travels through after it passes the sound heads. It's connected at the bottom but I'm assuming it stretches up and connects somewhere else [Confused]

[Confused]

...

Also, the sound is now warbly and I have to push the sound head down firmer into place. Or I can push the film downward after it passes the heads and that also fixes it - so maybe it's the amount of tension on the film? Is any of this adjustable? Maybe it's connected to the loose spring? Anyway, I didn't want to start turning screws randomly, but I also can't deal with sending it back a third time! Help from Kev (or anyone else) is appreciated... Thanks.

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Paul Adsett
Film God

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From: USA
Registered: Jun 2003

posted October 14, 2006 08:14 AM

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Hi Brian,
This looks like an easy one. From your description it sounds like its the small spring which should be attached to the little black plastic tension lever right below the sound head and just before he bottom sprocket. This spring attaches through a little hole in the black plastic bar, at its top end, and to a metal eyelet (which is bolted to the chassis)at its lower end.
This spring popping off is exactly the reason you now have WOW on your sound playback.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Brian Hendel
Jedi Master Film Handler

Posts: 902
From: New York, New York
Registered: Jun 2003

posted October 14, 2006 08:50 AM

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Paul - Thanks for the tip. It sounds like something even I can do! However, it looks like there are two indentations on the top of that black plastic lever... one towards the front and one towards the back. Which one does it attach to? It seems like the one towards the front would cause the spring to hit into the green plastic film path which seems like an odd way to design it? Also does the spring actually go through the black lever or merely sit on top of it? Thanks for any more help...

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Paul Adsett
Film God

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posted October 14, 2006 02:21 PM

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Brian,
This diagram shows how the spring is attached to the black film tensioner bar. There is a little protrusion on the bar ,close to the swivel point, that has a hole in it for the spring.

The function of this film tensioner is to smooth out the motion of the film and the variable take-up reel tension. Without this tensioner spring, you would get a lot of WOW on the film sound.
Note that the spring lies behind the green plastic film guide.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Kevin Faulkner
Film God

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From: Essex UK
Registered: Jun 2003

posted October 14, 2006 06:28 PM

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Its probably easier to remove the bottom green guide to get better access to the tensioner and its spring anchor points.

Generally the position of that lower anchor point (4) is between the 7 & 9 o clock positions as in the drawing. Note its position before undoing the screw to re attach the spring unless you are able to do this without removal.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Brian Hendel
Jedi Master Film Handler

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From: New York, New York
Registered: Jun 2003

posted October 15, 2006 02:15 PM

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That diagram is going to help a lot. Thanks... I am actually away from my GS till the weekend but I will let you know if it takes care of the WOW problem. It sounds like it will.

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Brian Hendel
Jedi Master Film Handler

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From: New York, New York
Registered: Jun 2003

posted October 21, 2006 01:55 PM

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Paul - Thanks again for the diagram... I did have the spring on completely wrong... Now for the bad news... after getting the spring on right, I am still getting strange sounding audio that wavers. The problem seems to be worse with stereo films for some reason. But it seems to get better when I push down on the large green plastic piece above the sound heads. Is there a screw or adjustment I can make that effects the way the film passes through the sound path? I'm thinking I can still fix this with a simple tightening or loosening of something but I didn't want to start blindly messing with the sound heads. If anyone has any suggestions please reply... Thanks again...

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Paul Adsett
Film God

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posted October 21, 2006 04:17 PM

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Hi Brian,
I think at this point we should request Kev to jump in.
I have a couple of ideas, but Kev can probably pin point this issue a lot better than I can.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Brian Hendel
Jedi Master Film Handler

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From: New York, New York
Registered: Jun 2003

posted October 21, 2006 04:51 PM

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Yes, I'd like some advice from Kev. I really am afraid to mess with the sound heads at all... Oh one more problem I just discovered. I'm getting no optical sound volume at all even though the bulb is on. I'm starting to think it may be time to get a different projector!

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Paul Adsett
Film God

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From: USA
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posted October 21, 2006 07:40 PM

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Brian, whatever you do, don't mess around with the sound heads. Once out of alignment, you will never get them back. This could still be a very simple and resolvable problem, such as the pinch roller pressure being insufficient. Don't give up- let's see what Kev has to say.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

posted October 22, 2006 03:33 PM

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Are the four plastic pegs applying pressure to the film to press it onto the sound head? Sounds like one or more of the springs in that little part may have gone.

--------------------
British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Brian Hendel
Jedi Master Film Handler

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From: New York, New York
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posted October 22, 2006 06:02 PM

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John - Can you give me a little more info? Are those four springs visible or do I need to remove parts to get a look at them? Thanks...

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Joe Taffis
Phenomenal Film Handler

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From: United States
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posted October 22, 2006 10:16 PM

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this post definitely diminishes the desire to aspire to acquire a GS1200.... [Wink]

[Wink]

I'll slave away with my ST1200D & ST800 thank you. [Smile]

[Smile]

--------------------
Joe Taffis

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

posted October 23, 2006 07:34 AM

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Thanks for that Joe!!!

Brian, you should be able to tell because the 4 little pegs each have a tiny spring behind them (which is only visible if you remove the part - which is simple to do) and you can tell if they're still working because if you press one back it should feel like there is a little pressure behind it and of course spring back out. If the springs are knackered, broken or simply missing the pegs will just be flopping about and useless.

Joe, isn't this part the same on the ST1200?

--------------------
British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Kevin Faulkner
Film God

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From: Essex UK
Registered: Jun 2003

posted October 24, 2006 12:53 AM

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Ok Guys here I am [Wink]

[Wink]

Sorry for not catching up on this thread earlier but I have been snowed under with the pressures of work.

Talking of pressures, I think that is the problem here. Pressing down on the green lever which houses the pinch roller sounds like the spring pressure of this part is too low. If this lever has insufficient pressure you will get quite bad wow on the sound and in optical sound the film will not sit tight round the sound drum which means the sound will be very bad to the point of being inaudible.
Another problem this could cause is the machines inability to to form the bottom loop properly.

Brian, When in optical mode do you get some sound when you press down on the green lever?

This lever has to press down at about 250 - 300g so quite a lot of pressure is required and on very early GS's it has been seen that this lever can crack at its fixing point and then slip causing these problems. The early GS's had an all plastic guide but the later ones had a redesigned lever where the anchor point has an alluminium sleeve insert at this anchor point to stop this cracking.

I would suggest Brian that you download the GS1200 service manual from the manuals section. You can then read up on the adjustment procedure for this part which is easier than me trying to go through in this post. Check for cracks in that lever and is yours all plastic at that anchor point. If you have the metal sleeved version then it could be down to adjustment or it's spring is missing or broken (inside rear of machine).

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Brian Hendel
Jedi Master Film Handler

Posts: 902
From: New York, New York
Registered: Jun 2003

posted October 24, 2006 06:15 AM

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Kev -I was wondering what was taking so long for you to respond...now I feel in secure hands (no offense to everyone else!) I will not be back in front of my GS until Saturday at which time I will check the points you are making. I was told by Leon Norris (the repair guy here in the U.S.) that I had one of the later versions of the projector - He could tell by which way the loop restore was facing. So maybe the fix won't be so bad... I will post back on Sat. I really would like to try to fix the problem rather than shipping it back for the third time. But again, it would have to be something simple for me to tackle it myself... Brian

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Paul Adsett
Film God

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posted October 24, 2006 09:28 AM

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Just a long shot Brian, but before you start taking things apart here are two other things that can cause excessive WOW on the sound playback:

1. The film is skiding on the brass capstan or rubber rollers.
Solution: wipe the brass capstan and rubber pressure rollers with alcohol and blow dry with air spray.Also make sure that the rubber rollers are spinning freely and also are not wobbling. If they are binding, try a tiny drop of oil on the roller shafts, make sure you dont get it on the rubber roller.

2. Pressure arm position
Adjust the position of the pressure arm to get 1.5-2.0mm gap as shown IN FIG 16-A (projector not running). Adjust by loosening the 2 screws (2). Make sure you position the roller in and out to get the little depression in the roller sitting over the ridge in the teflon film guide as shown in fig 16-B. Make sure screws are tight and arm is not cracked as pointed out by Kev.

3. The main drive belt is slipping.
Solution: Try wiping the drive belt, and motor and shutter pulley with alcohol. Or replace the main drive belt. Or adjust drive belt tension, by moving the motor, to get 5-8mm play as shown:

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Kevin Faulkner
Film God

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From: Essex UK
Registered: Jun 2003

posted October 24, 2006 10:03 AM

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Paul, It wont be the main motor due to the fact that pushing down on the lever sorts it. I do however go along with your tip about cleaning the brass capstan and its rubber roller. The first rubber roller wont make any differance as you can even run the GS without it. Its only there to reduce flutter. (If a machine is being used only for playback it could be removed to save wear on the guide where the roller presses at the entrance to the sound block. This will only work on the later film path versions).

If this is a late version then dirty capstan/pinchroller or the lever is out of adjustment. Check there is about 4mm gap between the Capstan and pinchroller in the stop position.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Paul Adsett
Film God

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posted October 24, 2006 10:16 AM

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I just clicked back on the forum, and the first thing I saw was that Brian is 'looking for the Excorcist'. I thought for a minute that he was still in this GS1200 trouble shooting thread! [Big Grin]

[Big Grin]

[Big Grin]

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Patricia Carpino
Junior
Posts: 21
From: East Hartford, CT, USA
Registered: Oct 2006

posted October 24, 2006 06:58 PM

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HELLO: CAN SOME ONE TELL ME WHAT THE WIRE TYPE "SPRING" JUST UNDER THE LENS ASS. WHERE THE FILM LOOP IS FORMED ON THE GS 1200 IS FOR? ALSO IS IT MENT TO COME INTO CONTACT AT ALL WITH THE LENS AS IT SWINGS INTO LOCK POSITION PRIO TO PROJECTION?
ANY LIGHT ON THIS AREA WILL BE HELPFUL... I CANT FIND IT IN THE MANUAL?

THANKS

Pat Carpino

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Paul Adsett
Film God

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From: USA
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posted October 24, 2006 07:53 PM

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Patricia,
I am assuming that you are referring to the curved wireform bolted to the swinging lens assembly by 2 screws, just below the spring loaded pressure plate. This is there to simply help guide the film into a small loop, before entering the sound head assembly. By virtue of the curved shape of the wireform, the film contacts the wire at its outer edges only, so film scratching cannot occur. The wireform does NOT contact anything when the lens is swung into place. I believe this wireform is only present on version 1 machines with the 'forward' lower loop. By version 3, which has the 'backward ' lower loop, it was gone.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Patricia Carpino
Junior
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From: East Hartford, CT, USA
Registered: Oct 2006

posted October 24, 2006 08:35 PM

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GREAT PAUL!

Yes, I must have the ver. one GS1200 YOU speak of because I see that the film does form a "bow" foward loop before entering the sound head assem. and does "ride this wire" in contact with the film!

THERE WERE A FEW THINGS I WAS CONCERNED WITH:

THIS WIRE IN QUESTION...DOES NOT SCRATCH (I SEE IT WORKS FINE AND SEEMS TO DO ITS THING IN HELP CONTROL THE LOOP..) CORRECT?

THE PURPOSE OF THE WITH IS TO CONTACT THE FILM FROM TIME TO TIME?

ON MY GS1200, THIS WIRE DOES SEEM TO CONTACT THE LOWER LENS ASSEM WHEN I SHUT THE LENS IN PLACE! IT SEEMS TO CONNECT AND LOCK AT THE SAME TIME AS THE REST OF THE LENS ASSM LOCKS INTO PLACE? I.E. (THIS WIRE HITS THE LENS ASSEM UNDERSIDE AND LOCKS-IN POSITION..BEST I CAN EXPLANE)

THE PROJECTOR WORKS FINE AND DOES NOT SCRATCH SO ALL SEEMS WELL WITH THE "WIRE" IN QUESTION...SO IM GOING TO LEAVE ALONE FOR NOW! JUST WANT TO MAKE SURE ITS OK..AND HAS A DUTY TO PREFORM.

HOW DO THE NEWER GS1200'S FORM THIS "REVERSE LOOP" YOU SPEAK OF WITH OUT THIS WIRE? LIKE I SAID, MY LOOP IS "BOWED" OUT TOWARD THE FROUNT OF THE PROJECTOR... I CANT PICTURE ANOTHER TYPE OF SET UP OR LOOP IN MY MIND? I CAN HOWEVER SEE A PROJECTOR WITH OUT THIS "WIRE". IT LOOKS LIKE ITS READY TO SCRATCH AT WILL!

THANKS PAUL

Pat Caprino

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Paul Adsett
Film God

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posted October 24, 2006 11:07 PM

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The version 3 GS1200 has a totally different lower loop forming system, utilising a moveable plastic film guide which is actually behind the fixed part of the metal film gate. This is designed to cause the film to fold backwards, away from the lens. Hard to explain, but it works fine, and is supposedly an improvement on the version 1 design where the loop folds forward, as in just about every other projector design that I have seen. Personally I don't see much difference in the performance of the two designs.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Patricia Carpino
Junior
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From: East Hartford, CT, USA
Registered: Oct 2006

posted October 24, 2006 11:38 PM

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I SEE...

SO WHAT DO THESE LOOPS DO..? ACT AS A "BUFFER" OF SOME KIND FOR THE SOUND SYSTEM?

Pat Carpino

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Kevin Faulkner
Film God

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From: Essex UK
Registered: Jun 2003

posted October 25, 2006 01:26 AM

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The little bit of shaped wire under the lens on the ver 1 machines is there for 2 reasons.

1, It stops the film loop if too big rubbing on the underneath of the lens holder assay. In optical film playback the loop is a little bigger and if the film rubbed it would get scratched. It's also there to help with picture steadiness.

2, The film without the wire is a little more unsteady (optically) as the loop forms straight off the bottom of the film pressure plate so any bounce and bad flutter in that loop shows up with a bouncing effect on the projected image. On the later machines the loop in effect goes away from the pressure plate so again on the ver 3 machines the picture is a lot steadier.

Now, the reason Elmo changed the film path on the later machines was again for 2 major reasons.

1, Optical sound playback was more problematic on the ver 1 machines and some times the lower loop just doesnt form properly especially with the very thin based film stocks. How many ver 1 machine owners are there who have got used to having to use the loop former on these early machines because the loop doesnt form quickly enough after the autothread releases? This is not a problem with the later rear loop design.

2, Again the early ver 1 machines suffer more from flutter as do the ST1200's and many other machines. Unlike STD 8 the picture to sound seperation is quite small so the film movement has to be smoothed out in a very short gap otherwise this movement can be heard on the films soundtrack. Super 8 is 24 fames sep and STD 8 is 54.
Hands up those who have heard a beating noise on very load passages of sound especially on comercially produced films?
Again the straighter film path of the later machines means that this problem is virtually licked. I dont think I have ever heard flutter on my Xenon which has the later film path but my ver 1 std machine was a nightmare for this problem on certain highly modulated soundtracks.

The ST600 machines were very good in this respect which is why I think Elmo changed to this layout and with the little rubber roller in front of the sound head on the GS we now have a machine without this flutter problem.

Hope that helps clarify things.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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