Film-Tech Forum ARCHIVE: Weird problem with splices

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Posted by Kevin Markwick (Member # 2698) on 10-10-2004, 06:53 AM:

Had real problems last night. Kept getting racks in a feature than has been running for two weeks. Further investigation revealed that the film had folded over causing two sproket holes to overlap. This is splicing tape we have been using for years with no problems and when I pulled the film back there was no gap, so the projectionist who made the film up had spiced the joins correctly.

We have recently installed Kelmar cleaners on all our mechs and have been using Film Gaurd with spectacular results. So I suppose my question is could FG be weakening the joins causing them to fold over?

I hope not as I am now a FG zealot and spread the word every chance I get. Any suggestions greatly appreciated.

Posted by Dominic Espinosa (Member # 2122) on 10-10-2004, 11:12 AM:

What tape are you using?
The only way I can think of that FG could weaken the splice would be if the splice tape was already pretty weak and the splice was very loose allowing excess filmguard to get down under it and disolve the adhesive.

If the film is being litteral folded over onto itself there's something way more severe going on. I'm not sure what though.

Posted by John Anastasio (Member # 607) on 10-10-2004, 11:56 AM:

Sounds to me like he's only making the splice on one side of the print.

Posted by Kevin Markwick (Member # 2698) on 10-10-2004, 12:03 PM:

Both sides are taped. We're not that green.
The tape is supplied by Omnex here in the UK, a very reputable supplier. It is quite wide (4 perfs). Went through the whole print this morning and had to remake every join. As I said the joins had no gaps so I would summise they were made correctly.

I asked the question because in 25 years of showing films having encountered most things I've never seen this. The only thing that is different in the box is FG.

Posted by Brad Miller (Member # 2) on 10-10-2004, 01:01 PM:

It is due to print moving (platter) or rewinding (changeover) where the film is allowed to slip on itself and the wind is not being presented proper backtension the entire time. Seen it happen with many different kinds of tape, FG or not. I saw this quite frequently at a local Strong booth where prints had to be thrown over your shoulder and carried up and down stairs a lot. Those Strong rings like to bend easily. It was the bending that caused the pressure (and cinch scratches) which did that to the splices.

Posted by Kevin Markwick (Member # 2698) on 10-10-2004, 02:12 PM:

Thanks very much Brad. That would actually make sense as the problem appeared after we moved the print from a theatre running a platter to one with a tower. Learning from your experience, I would guess the part time Projy on Friday rewound the film without enough back tension on the tower. In too much of a hurry probably.

In the words of Peter Sellers (that was the film) I shall have speaks with him.

Posted by Neil Robinson (Member # 2459) on 10-10-2004, 06:46 PM:

Kevin I had the same problem with splices when I was using Westrex towers, overlapped splices would run a couple of days and then end up the same way as you describe, in fact butt splices is all I could use, I think it is something to do with the re winding on the tower system, we now have platters and have never had that problem, I overlap about 1mm and use Jack Roe tape, having used tape from other companies in the UK I don't think you can get better than Jack Roe tape as it chemically resistant to oils, solvents and grease.
Neil Robinson
Gala Cinema
Durham City UK.

Posted by Brad Miller (Member # 2) on 10-10-2004, 07:18 PM:

Are these towers not providing a steady backtension during rewind? I wonder if they are free-wheeling like a Strong platter (un-modified) does during breakdown. That'll do it big time. (Plus tiny cinch scratches will develop, mostly toward the ends.)

Posted by Leo Enticknap (Member # 534) on 10-11-2004, 04:50 AM:

I've had serious backtension issues with practically every Westrex tower I've used, both running and rewinding. The tension has to be set manually and constantly adjusted during the show. Their fans say that when properly operated and meticulously maintained, this isn't a problem, but to my mind they're a pain in the bum and easily the worst long-play film transport device I've ever used. In one venue I worked a relief shift at, the chief had even left a pair of gardening gloves to supply the back tension by hand!

Posted by Stephen Furley (Member # 1277) on 10-11-2004, 05:50 AM:

quote: Leo Enticknap
to my mind they're a pain in the bum and easily the worst long-play film transport device I've ever used

Even worse than those star-shaped endless loop things at MOMI?

I've only run towers a handful of times, but I don't like them much. The tension seems to be all over the place, on a projector with a fast start it's all to easy to snatch the film as you start the thing, the Westrex towers have a ridiculous rewind speed, and a lot of operators just seem to rewind the thing as fast as they possibly can, which certainly doesn't help when the film is wound slack. Of course, if you are running the same film in two consecutive shows, then you have no alternative to rewinding it fast. Most of the places where I've seen towers run the adverts and trailers on a 2k or 6k spool on the projector while the feature is rewinding on the tower, but even then, you often only get about 15-20 minutes to rewind the feature; that's much faster than I like to do it, certainly with poor tension on the film being rewound.

Having said that, the Odeon Leicester Square ran a Cinemeccanica tower for many years. It was installed during the days of the Vic Xs, remained in use while they had the Vic 8s and was only removed when the new machines which can take large spools directly were installed during the last refurbishment a few years ago.

Posted by Kevin Markwick (Member # 2698) on 10-11-2004, 07:27 AM:

Sadly we don't have the space for a platter in the box where I had this problem over the weekend. Despite everyones reservations about towers this is the first time I have ever had a problem.

As I said before my guess is the relief on Friday wound it a couple of times without sufficent tension on the take up spool during rewind.

There are of course fors and againsts with towers. With a tower it's a lot easier to change the programme around, add or take out trailers, make repairs etc. If I'd had to remake all the joins on a platter I'd have been there all morning.

The biggest downside is the rewind time. We have three boxes in different parts of the building and we are often forced to leave the tower rewinding while we take off another show. If you don't get the tension right, phew what a mess!

Posted by Leo Enticknap (Member # 534) on 10-11-2004, 08:47 AM:

quote: Stephen Furley
Even worse than those star-shaped endless loop things at MOMI?

True, not as bad as those. That having been said, they weren't really long play (70-80 minutes was about their maximum capacity - try loading any more and it would be on the floor within minutes) and certainly not a device which any serious cinema would ever have used, hence the reason I didn't include them.

quote: Stephen Furley
Having said that, the Odeon Leicester Square ran a Cinemeccanica tower for many years.

Those are a very different kettle of fish to the Westrex towers, and if I had to have a tower at all, it would be one of those. They set their tension automatically - I'm not sure how, but seem to remember that they sense the changing weight of each spool and adjust a some sort of clutch in response. I worked in two places which had one (one of which was also MOMI, incidentally) and never had any problems. They gave a good, clean solid wind without being too violent or letting the film go slack, and without having to make any adjustments during the show.

Posted by Kevin Markwick (Member # 2698) on 10-11-2004, 09:34 AM:

The other good thing about the Cinemeccanica tower is the dead
arm that shuts it down after rewinding.

I ran a Westrex tower for years with no problem. One of the things to watch for is the carbon contact on the variac. If this wears down it can cause the erratic tension problems Leo describes.

Posted by Greg Routenburg (Member # 1742) on 10-11-2004, 10:07 AM:

I gotta say, I've never seen this and am having a little trouble visualizing it. So the film creased on the frame line and hinged at the splice causing a 2 perf overlap? I use strong rings and have been for a few years now, is there anything that can be done when moving the prints around to avoid this happening?

Posted by Kevin Markwick (Member # 2698) on 10-11-2004, 10:44 AM:

You describe it perfectly Greg. Sproket four on the outgoing frame sitting over sprocket one on the incoming frame, as if you
had too much overlap on a splice.

Dang thing. I have to say a newcomer to the forum Brad and everyones input has been invaluable. Thank you all very much.

Got it sorted now. It in fact turned out to be a combination of slack winding techniques by two of my staff that I didn't realise was happening. Firstly, because he had to take the film off the platter in screen three onto a spool for transfer to a tower. The problem here is that Cinemec platters have no back tension when going out to the make up table. The only thing you can do is apply a little pressure to the plate with your hand. He obviously didn't apply enough causing, as Brad suggested, the film to slip on the spool.

Secondly, the relief rewound the film too fast on the tower compounding the problem. I have had serious words with all concerened.

The print, however, shows no sign of scratching or crimping or anything else. Still in pristine condition thankfully. It's just very strange that this has never ever come up before, which is why I questioned FG weakening the joins.

Phew!

Posted by Hugh McCullough (Member # 1542) on 10-11-2004, 11:10 AM:

quote: Stephen Furley
the Odeon Leicester Square ran a Cinemeccanica tower for many years. It was installed during the days of the Vic Xs, remained in use while they had the Vic 8s

The Cinemeccanica tower MK1 at the Odeon Leicester Square was installed in 1977. We did have some trouble with the motor start condensers burning out. We discovered that they were in circuit all the time the tower was running. Overcame this by fitting a double switch. One side of this switch was spring loaded, and returned to the off position when released. The other side stayed in the 'On' position. The sprung loaded side we connected to the condensers

quote: Leo Enticknap

They set their tension automatically - I'm not sure how, but seem to remember that they sense the changing weight of each spool and adjust a some sort of clutch in response.

The automatic film tension on the take up spool was, if I remember correctly, adjusted by the spindle being able to move downwards under the weight of the film thereby altering the take up tension.

I have found that when rewinding a feature on a Westrex tower it is best to set the speed to 90. The film then stops rewinding about 2000ft before the leader. Then you can finish winding at about a speed of 60. Takes about 12 to 15 minutes doing it this way.
Also have to use butt splices. For some reason Westrex towers do not like overlap splices.

Posted by Stephen Furley (Member # 1277) on 10-11-2004, 12:14 PM:

quote: Leo Enticknap
True, not as bad as those. That having been said, they weren't really long play (70-80 minutes was about their maximum capacity - try loading any more and it would be on the floor within minutes) and certainly not a device which any serious cinema would ever have used, hence the reason I didn't include them.

Kinoton make one of those endless loop things, web page they claim that theirs will run 5000 metres of film; I'm not sure I'd want to try it. How do you load the film onto these things? I wouldn't have thought that you could just run the film onto it like you would with a normal platter, do you run the print off a spool, through the projector and then just take up on this thing, stop to splice on each new reel, then retrieve the start of the film from the centre and splice it to the end?

I believe there are a few 'normal' cinemas which have this sort of thing, but I've never seen one.

quote: Hugh McCullough
The Cinemeccanica tower MK1 at the Odeon Leicester Square was installed in 1977. We did have some trouble with the motor start condensers burning out. We discovered that they were in circuit all the time the tower was running. Overcame this by fitting a double switch. One side of this switch was spring loaded, and returned to the off position when released. The other side stayed in the 'On' position. The sprung loaded side we connected to the condensers

The Phoenix, East Finchley had one from the time they installed a FP-20, I think it was 1986, until a couple of years ago when it died, and was replaced by a Westrex one. I think it was some sort of electrical problem. This had the double switches whenever I saw it, from sometime in the early '90s, but I don't know if it had them from new; It wasn't new when they got it. The Westrex towers seem to have been more common than the Cinemeccanica ones; there are still loads of them in use.

I've been in the box at Leicester Square just once, many years ago now. The three Vic Xs were in then, but no tower. I think they still had the large Zenith arcs on them. When would this have been, early '70s? Was this during your time there?

I've met Nigel Wolland a few times, but never at the Odeon. I should have asked if he could get me another visit.

This will probably be my last post for a while. Tomorrow and Wednesday I'm busy tying up loose ends at work, Thursday I'm off on holiday until the 28th. I've then got a couple of days off to sort out a few things before starting back at work on the 1st of November.

Best wishes all.

Posted by Leo Enticknap (Member # 534) on 10-11-2004, 03:12 PM:

Thanks for the info on Cinemec towers, Hugh. My memory of them is a very positive one - you just pressed the button and off they went, be it running or rewinding. At the end of the pass, the film was always wound evenly and solidly, but not so hard as to risk cinching. The Westar towers, on the other hand, required constant babysitting and usually managed to do something nasty to the film. Plus they also had horrid screw clamps for securing the spools on their spindles, with a nasty tendency to work loose. I had one spool fly off during a rewind and dread to think what would have happened if I'd been in its way at the time. The Cinemecs, on the other hand, had a conventional securing flange - just like any other spindle on the face of the planet.

quote: Stephen Furley
How do you load the film onto these things?

It's well over a decade since I've used one, but in essence the technique was to cycle the programme round to the point at which the splice you want to insert or remove footage at is positioned between the bottom of the projector and the platter intake. You then undo the splice and either offload film from the feeder, through the projector and onto a spool; or from the projector's feed spool, through the projector and onto the programme.

How you get film onto an empty platter I don't know. It must have been a major faff because we were told never to do it, i.e. winding several thousand feet of crap spacing onto a plate temporarily was preferable to having to load one from empty. This might just have been a personal preference of the chief who trained me, but at the time I hated the things, wanted as little to do with them as possible and was very happy to obey orders!

Posted by Hugh McCullough (Member # 1542) on 10-11-2004, 05:02 PM:

Stephen,
Sorry, but I made a mistake. The Cinemeccanica tower was installed in 1976, (see http://www.cinephoto.co.uk/odeon_leicester_square_5.htm) and the Zenith arcs replaced with AutoArc Xenons.
These were a disaster with overheating problems, caused by a fan that worked when it wanted to, and had too small a hot air outlet. About two years later were themselves replaced with Zenith Xenon conversions. (Bernard Bentley)

I agree Leo. The Cinemeccanica tower is a far superior piece of equipment, but I did have a feed spool fall off with about 6000ft of film on it. This was caused by the small pin holding the spindle clip on to the shaft falling out.
Cinemmeccanica were amazed, and keep saying "That's not supposed to happen". Maybe not, but it did.
To keep the spool on the Westrex tower requires either tightening the screw clamp with a wrench (not recommended), or using a locking nut.
Have you ever tried to replace a motor on the Westrex?
The are so heavy that it needs two people to do the job. One to remove, and replace the panel screws, and one to hold the whole assembly in place. A real pain if it is one of the upper motors.

Posted by Leo Enticknap (Member # 534) on 10-12-2004, 02:38 AM:

quote:
his was caused by the small pin holding the spindle clip on to the shaft falling out.

I guess the centrifugal force generated by a full spool spinning at rewind speed must put quite a strain on that pin. I hope they managed to produce a mod to strengthen it.

I came across various improvised techniques for making the Westrex spool clamp stay put, which their inventors all swore by (and I usually swore at). A piece of cardboard in between the clamp and the spool was usually better than nothing, but I would still make sure I was behind the operating side while rewinding! At one place I worked a few relief shifts they had discarded the 'official' clamps altogether and used enormous brass nuts, a rubber washer between nut and spool, and tightened with a big socket wrench. As you say, monkey wrenches are another way, but after a few months of that there doesn't tend to be much left of the spindle thread.

I never had the pleasure of changing a Westrex motor, but have helped to shift two GK-37s (pedestal, mech and lamphouse) up a flight of 47 stairs!