8mm Forum: Refurbishing your GS1200

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Posted by Alan Rik (Member # 73) on December 31, 2015, 08:11 PM:

I was looking over some older posts and I saw Ugo's post about his 'reborn' GS1200 Xenon. Really a fantastic thing to be able to do.
I have the service manual and can do the smaller things like changing a bulb! Occasionally removing the Motor Control board and giving it to an engineer to repair and then placing it back into the machine.
But for a job like a rebuild, is the Service Manual enough or do you need to have a degree in electronics? I am curious because I would love to take my Xenon down to the nuts and bolts but my fear is it will never be built back up again!
When looking at the service manual there are many little tools that I don't have but I wonder if its necessary. For instance the Bar Spring scale, Oscilloscope, test films, all the different kinds of grease, etc.
Ugo.. feel free to chime in! How many man hours did it take? If I lived nearby I would pay you to teach me! Love the purr of a refurbished projector.. nice full audio..no wierd noises..like a new car.
Ideas?

Posted by Steve Klare (Member # 12) on December 31, 2015, 10:49 PM:

I have a degree in electronics and I'd feel uncomfortable taking on a job like this without somebody who's done it a few times walking me through it.

What I always run into is the documentation always makes more sense after it's demonstrated live at least once.

It's part of the challenge facing this hobby with the years going by, not just the parts but the know-how.

Posted by Alan Rik (Member # 73) on December 31, 2015, 10:57 PM:

Next year you and I can go to Avellino Italy and have Ugo show us! Are you in? 👍

Posted by Steve Klare (Member # 12) on December 31, 2015, 11:06 PM:

-have to do it in secret:

It's kind of critical to never admit having any useful skills.

-You can't imagine how many ceiling fans I wound up hanging because my Mom told her friends I was in technical high school!

HAPPY NEW YEAR! (-at least here!)

Posted by Andrew Woodcock (Member # 3260) on January 01, 2016, 03:00 AM:

Rik, in answer to your first questions here, The pull force guage, the oscilloscope, the different grease selection etc etc are all necessary to use as accurate and scientific measuring devices and the grease selection as the preferred correct lubricant if you want to recreate the professional standards to which these machines were designed and built to in the first place.

You can of course, take many short cuts and do away with one half of the pro equipment and still be able to achieve some very good results. However, if you want your machine as you describe, like a brand new one, then really everything would have to be set as such using the professional and accurate measuring devices to do so.

This is where the guys who have a workshop fully equipped with these professional instruments and tools, like Bill Parsons and Ugo seemingly does, will always be able to achieve excellent results from their days work as they almost certainly eliminate any guess work when carrying out their repairs.

To me, having the ability to recognize your motor circuit board has a fault, then be able to successfully remove it to send it away for professional repair using the instruments and tools described, then having the ability to build everything back together again successfully, is about as good as anyone in a standard home environment with a standard set of tools, could ever realistically expect.

This is something that you really should be pleased with yourself for rather than pointing out deficiencies I'd say.

The end result is all that matters and a working projector, no matter how many people we involve to get there, is the result we all want to achieve.

The closer you can possibly get to ensuring all repair procedures are carried out to a professional standard, the greater chance you will have of obtaining a "like new" feel to your machine. Always try to use the genuine parts where possible (with the exception of the Elmo film guides), and use only the recommended lubricants or the very nearest technical equivalents if no longer available.

The degree in electronics would certainly help you understand many of the electrical and electronic faults on the complex machines like your xenon, but you have to also have the practical skills and confidence to carry out the repair and the rebuild to the same or similar standards that a repair technician or engineer would.

This is something that can only ever be learned through experience in the field so to speak, and no University course would necessarily teach you all of this.
Also many extremely well educated and technical people I have met, do not always possess the most logical set of troubleshooting skills I have found.
This, again, is something that only experience of regularly doing this act, can possibly give you even one half of the skills you need to have a chance of doing this regularly with a modicum of success.

[ January 01, 2016, 04:22 AM: Message edited by: Andrew Woodcock ]

Posted by Tom Photiou (Member # 130) on January 01, 2016, 05:36 AM:

It would be great to be able to do these things, its where you realise how good the Bill Parsons of the world actually are,
I have the service manual for the 1200ST series and would love an old defunked ST1200 just to go through the book a page at a time to dismantle it, and do what i could with it then get it back together,oh and not have 2 screws left over [Big Grin]

Posted by Brian Fretwell (Member # 4302) on January 01, 2016, 07:26 AM:

I had an apprenticeship that involved taking Creed mechanical teleprinters apart and reassembling them as training and I would be nervous about doing this to a projector, even with the full service manual.

Our manual for the printers had 30 odd pages on how to dismantle the machine and only one for re-assembly it said simply "Re-assemble in reverse order" [Smile]

Of course there were many pages of adjustments after that.

Posted by Alan Rik (Member # 73) on January 01, 2016, 09:32 AM:

Happy New Year everyone and thanks for the replies! The lovely Ugo replied to an email that I sent him earlier and he learned the old fashioned way. He had a Yoda of projector repair help him learn along with his own desire. And he learned one screw at a time!
That was such an inspiring story to start 2016 I think.
Eccellente!

Posted by Paul Browning (Member # 2715) on January 01, 2016, 10:00 AM:

If it ain't broke, don't fix it.

Posted by Paul Adsett (Member # 25) on January 01, 2016, 11:27 AM:

I agree with Paul, " If it ain't broke, don't fix it". Stripping down a projector is always a risky business, and in the case of the GS1200 there are many things that can go wrong in the process. So if it's working OK, leave it alone, except for routine cleaning and lubrication.
But every so often you have to bite the bullet and attempt a repair yourself, unless you want to pay for the cost, and risk, of shipping the projector to Bill Parsons or Leon Norris.
I once had to strip out all the electronics from my GS to replace a couple of relays on the main PC board. It was a time consuming process, taking several hours over a 2 day period, and I had no idea how successful the repair was until I had it all back together, but it was a total success. It pays to say a silent prayer when you fire up the machine again for the first time!

Posted by Alan Rik (Member # 73) on January 01, 2016, 01:32 PM:

Yes I hear you but its so nice to use something the way it was when new. I have had a few chances to do it. I bought my GS1200 like new (my first one and it was 1983) and I remember the recordings it made were great, it never scratched films (that I noticed) and it also purred and never made wierd sounds. I call the GS the King of Weird sounds. Even though it is one of my favorite projectors.
I'm taking an electronics course so I can at least figure out the non-mechanical aspect of things. Maybe I can apprentice with Leon? Hmm....

Posted by Paul Browning (Member # 2715) on January 01, 2016, 02:40 PM:

I would ask a mechanic friend of mine to have a look at my car as I can hear the tappets on the engine "tapping", he would answer, " the time to worry is when you cannot hear them tapping". This machine was ahead of its time when first introduced back then, with all its features and sophisticated recording facilities, you can forgive it that "run in" sound that you speak of. It's still one of the only projectors (Super 8) you can still get the sound heads for, and for the most part all other components can be repaired and improved as you go, this does not involve taking every part off the frame to do it, as they are made in modular form, as is typical of the Japanese products of the 70's and 80's. It's about knowing your limitation's as to how much you can do without causing more damage, which will cost twice as much to put right if you get it to someone who knows what they doing.

Posted by Andrew Woodcock (Member # 3260) on January 02, 2016, 05:43 AM:

The Beauty with the GS as Paul points out, is it is very modular in its design. Most repairs can be carried out by just taking a sub assembly out to repair it.

[ January 02, 2016, 05:23 PM: Message edited by: Andrew Woodcock ]

Posted by Dino Everette (Member # 1378) on January 02, 2016, 06:23 PM:

quote:
Rik, in answer to your first questions here, The pull force guage, the oscilloscope, the different grease selection etc etc are all necessary to use as accurate and scientific measuring devices and the grease selection as the preferred correct lubricant if you want to recreate the professional standards to which these machines were designed and built to in the first place.

I agree with what Andrew has said here, but I know I have asked multiple times on multiple forums for examples of currently available grease/lubricants and never received a successful reply, so here we go again...

What would be the current equivalent products for GS owners to use for the recommended lubricants listed in the GS service manual ...Maybe even a UK / US list if they go by different names/brands...

A - Daphne 44
B - Veedle 20-40
C - Alvania Grease 2
D - Aluminum Grease 1
E - Molykote EP

This way everyone could at the very least maintain the proper lubrication.

Posted by Andrew Woodcock (Member # 3260) on January 02, 2016, 08:01 PM:

C,D,E are still definitely available in industry today here in the UK. I know this because I use them all.

A& B seem a little less familiar now so let me do a little research into their properties and I will get back to you on these with equivalents if they're no longer available.

Correct me if I'm wrong, but the Daphne 44 product appears to be a Idemitsu mineral oil of Asian origin. Probably very easily substituted by an American or European equivalent.

Just like the original Bosch silicone oil used for Bauer felt pad. It is long gone but so long as you find something even closely resembling the original, you really won't be a million miles away.

Our projectors by no means either test the load limits or temperature range of any professional application lubricant.

Incidentally, I do and don't go with the adage of "if it ain't broke don't fix it".

It's a very contradictory subject, but most of my own personal learnings are taken from a machine at work or in the home, while it's still working perfectly well.
If you take nothing from any machine while it works well, how on earth do you stand any chance of diagnosing it once it goes wrong???

You very much, need to know exactly how it is supposed to work in the first instance, to even stand a chance when it no longer does.

By the same token,I don't believe in meddling unnecessarily, any intervention comes with a risk!

It's all about having the wisdom to know when it's best to take a look at what's going on, I find.
It's very much an area covered in grey and certainly not a black and white debate.

Posted by Dino Everette (Member # 1378) on January 02, 2016, 11:59 PM:

quote:
Correct me if I'm wrong, but the Daphne 44 product appears to be a Idemitsu mineral oil of Asian origin. Probably very easily substituted by an American or European equivalent.

Andrew - yes I believe this to be true, but the dilemma is which Daphne oil, they have different kinds...I am assuming the 44 was the grade, which is now listed as 46, but which kind (mechanic oil, mechanic oil EF, or super multi oil)

Posted by Andrew Woodcock (Member # 3260) on January 03, 2016, 04:16 AM:

I think the 46 grade mineral oil would be your nearest equivalent now Dino.

As said, our projectors really don't test these lubricants to their extremes in either temperature or load resilience.
A good equivalent will always suffice I'd say. Certainly this policy has worked fine for me anyhow.

You just have to match the type of lubricant above all else as for instance, not all grease is suitable for nylon gears etc for example.

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