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Author
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Topic: ST 1200 question
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Craig Crane
Junior
Posts: 3
From: England
Registered: Sep 2007
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posted October 06, 2007 04:17 AM
Thanks guys.
This shutter wheelhas no rubber on it, and the belts are like warm liquorice... I ran a old test reel last night and it was just painfully slow.
The edge of the shutter wheel does not look like it has ever had rubber on it.
Heres the rub though, of the three super 8 units I have brought on the Bay this month, all of them have had issues.
The least being a damaged take up reel on a S 905 GL (but I dont use it as its noisy and I dont like the way the reels layout.
A Eumig s 934 looked perfect on the surface, but when I opened her for a deep clean, the large metal body inside had what looked like a white powder type corrossion on it that I now need to get rid of as this could fall of and settle in the gate..... beed I say more?
And then the 1200. This looks like it took a knock in transit. It was shipped in its original black carry box, with nothing more than a thin cardboard box surrounding it. Its carry handle was expossed to ease carrying for the courier, but that looks like that may have been an impact point as its shattered. As was the take up reel included in the box.
The sound circuit has a ground loop hum all the time, even through headphones.
Optically its fine, and a marked improvement over my others, but whats the point when playback is marred by wow & flutter.
I have ordered some new belts from a supplier on E bay. Although advertised as being for the st1200, classic home cinema in the UK has since told me that these are not specifically for the machine. They are just a size match.... Another 15 quid down the drain???
Whats really p*ss*s me off though is the fact that I have nothing but good luck with the films I have purchased.
Ironic that I as yet dont have a glorious st1200 to play them on.
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www.craigcrane.co.uk
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Bart Smith
Expert Film Handler
Posts: 228
From: Hackney, London
Registered: Feb 2007
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posted October 06, 2007 04:29 PM
IPA is indeed ideal as a tape path cleaner - great for heads, tape guides, and all other parts other than the pinch roller. The wet style tape cleaners that you are talking about were based around petroleum distillates, not IPA. Tape head cleaner that is sold tends to be IPA, but it is never described as being 'Pinch Roller Cleaner'.
The point is that IPA worsens the grip/friction of the roller. Saying that a little bit here and there is OK is a bit like saying that paint stripper is great for cleaning your fine china. Fair enough, a little bit won't seem to do any harm, but you are playing with fire.
My business has been repairing tape machines since the early 90's, I know what I'm talking about. Research the question on the internet - you'll find a vast body of evidence out there which will point you to the error of your ways.
The damage that IPA does to rubber is not immediately apparent - it take some time to manifest itself. One application is not likely to do significant harm, but repeated application will result in the outer surface developing a crazy-paved pattern of minute cracks, and the roller will no longer do the job it is meant to do.
Use the correct cleaners as I suggested above. But please don't use the excuse that you've never noticed any problems - it is not a good reason to recommend it.
Kevin, I'm not trying to attack you here: we all have different areas of expertise. I would hope that you would take note of what I have said, research the issue, and then come back with a better informed and considered answer.
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www.bluecinetech.co.uk
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Bart Smith
Expert Film Handler
Posts: 228
From: Hackney, London
Registered: Feb 2007
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posted October 09, 2007 05:47 PM
I think that there are some important qualifications that need to be made regarding some of the responses above.
Rick Skowronek said: quote:
We always used denatured alcohol (IPA) on the pinch rollers. Other parts including the tape heads we used Freon TF, a totally non-reactive cleaner.
Now this is not just my opinion but many very heavy experts in the field with many years in the business. Here is one from a professional sound engineer and member of the Audio Engineering Society, Accoustical Society of America and chairman of the AES Standards Subcommittee: "I would be very cautious cleaning the rubber pinch roller with anything BUT alcohol. Most other solvents can damage the rubber by dissolving it and making it sticky. While it is true alcohol can dry rubber, it does so very slowly, and treatment once or twice a year with platen cleaner will restore the rubber surface."
I have to totally agree with Kev on this both personally from my experience and from other very knowledgeable field experts.
Rick - the practice that you describe is substantively different from that which Kevin was recommending. Your quote from the guy at the AES makes it clear that his opinion is that cleaning pinch rollers with IPA is only OK in conjunction with regular and periodic application of platen cleaner to restore the surface. The result of only using IPA without subsequent application of platen cleaner - the pinch roller will slowly dry out and get worse and worse at performing its proper function, eventually becoming cracked, deformed, crumbly and useless. Once the damage to the rubber surface has become severe, it cannot be restored with platen cleaner/rubber restorer. You need a new pinch roller.
Rick, you say that you "totally agree with Kev on this". Taking into account what I have pointed out, do you still agree unreservedly? Would you really "give the pinch roller a good clean with Isoprop" as Kevin suggested without getting your platen cleaner out at some point later?
I have made the assumption that both Joerg Niggemann & Rick Skowronek are referring to the maintenance of professional open-reel recorders such as 24-track 2" machines. Please correct me if I am wrong. Maintenance and servicing schedules of equipment like those (worth potentially 5-figure sums) are somewhat different from those appropriate if you are dishing out advice to someone posting on an internet forum looking for guidance who has just bought a Super 8 projector on ebay.
In a professional environment the equipment will (hopefully!) be regularly serviced, by experienced technicians, in a predetermined and periodic pattern. In the specific case of the pro open-reel machines that I assume Joerg & Rick are referring to, the pinch roller is ultimately a consumable. It is typically the manufacturer's recommended practice to replace them after a few thousand hours of use, which is why they are normally easy to remove and replace without dismantling the machine. I recently bought a new (not NOS) pinch roller for a Tascam 1/2" 8-track machine that was manufactured in the late 80's. This is not something that one can do if you are looking for a replacement pinch roller for a Super 8 sound projector, as spares are not readily available. Your only choice is to maintain the pinch roller using the best practice that you can follow.
To simplify matters let's consider the following 3 practices (not an inclusive list, there are many others).
1) IPA then periodic treatment with Platen cleaner (as suggested by Rick).
2) Detergent solution cleaned off with water.
3) Cleaning with IPA (as suggested by Kevin).
If you are a dedicated user committed to organised and regular maintenance, practice 1) may well be the best.
If you are an amateur but serious enthusiast who wants to get the best out of your machine without too much fuss, practice 2) may well be the best.
BUT it is my opinion that practice 3) is the least advisable and most dangerous of the lot, as it is most likely to permanently damage the operation of your projector in the long run. It won't seem apparent immediately, but....
....most of the Super 8 projectors that we are concerned with in this discussion are 30 or so years old now. It would be nice to think that they could be up & running properly in another 30, 60, 90 years....???
At work I regularly come across pinch rollers from 20-50 year old equipment that have been ruined by treatment with chemicals such as IPA. They are frequently irrecoverably damaged. Don't let that happen to your cherished projector.
The only way to ensure this is by adopting the appropriate best practice that most suits your circumstances.
Kevin said when that he worked for Ilford in the 70's "The rec for cleaning the film path including the pinch roller on sound machines was to use IPA". I would take issue with that statement. The long-term stability and durability of rubber, rubber composites, other plastic and foam components back in those days (and before) were not as well understood or documented as they are now. Rubber becomes gooey or cracks and dries out, plastic become brittle and decays, and foam deteriorates and crumbles. What seemed to be good practice then should not be taken as an article of faith for good practice now.
This site is billed as being a discussion 'forum'. I'm not trying to attack any sacred cows here. I am however interested in establishing through discussion and debate what is best practice, and I'm convinced that there is more to be constructively said. In fifty years time people will read all of this and laugh about how shockingly naive and ill-informed all of our opinions are. But that will be the benefit of hindsight.
Bart
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www.bluecinetech.co.uk
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Graham Ritchie
Film God
Posts: 4001
From: New Zealand
Registered: Feb 2006
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posted October 10, 2007 03:39 AM
One interesting point that was mentioned, Quote "Rubber becomes gooey or cracks and dries out" I agree and its often an an "age thing" and there is nothing one can do about it, many projectors are at least 30yrs old, and when you think about it, the rollers are subjected to heat and wear over a long period, so after say, those 30yrs how can one prove that by using "Isoprop" on a cotton bud to clean rollers, and the stuff does evaporate quickly, is in any way causing problems, one also has to remember that in another 30yrs time, not only will the projectors be well and truly worn out but so will I ![[Wink]](wink.gif) .
Graham. ![[Smile]](smile.gif)
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Tom Photiou
Film God
Posts: 4837
From: Plymouth U.K
Registered: Dec 2003
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posted October 10, 2007 02:37 PM
Lee, did you get these from a Mr moss?
I'd like to see if anyone has done a full review of this item,
Ive recently,(and thanks to a very well known projector repairer) done my own shutter replacement, the rubber had been removed but also and this is new for me, the shutter was very very finely machined on the shutters edge to give it a perfect flat edge instead of the very slightly rouned edge and i must say its brilliant and makes it run quiter.
Rick/ When i recieved the cleaner i read the the warnings that were sent with it, i think i need the bomb squad in when i use use it ![[Big Grin]](biggrin.gif) it certainly is toxic but as you say, if used sensibly it should be fine and i must say, it dont half move the dirt and with so much ease. It took the sticky bits off my new rubber that i fitted to my machine with total 100% ease. i then used it to clean the edge of the new shutter and its all perfect again.
the jist is, a good cleaner, used sensibly should be more than good enuf for our hobby, i thank you
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