Film-Tech Forum ARCHIVE: I am a novice looking for advice on a problem print and or projector

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Posted by John Davey (Member # 4828) on 06-20-2010, 10:42 AM:

Hello all

I new to the world of 35mm projection. I have been working at a local one screen for a little less than a year, although I have been a film collector for quite a few years. My technical knoledge is minimal. I can thread a projector and usually run a print successfully.

In say usually because as of late, I've been having a problem with a print I run once a week snapping and breaking during projection. I am trying to figure out if it is user error, a mechanical cause with the projection head, or if th print, although it appears to be fine, is just to old and brittle to handle a once a week run.

Out theatre has Ballentyne Pro 35 heads. The print in question is a composite from several different prints. I've inspected and cleaned it several times. It seems to have a normal level of flexability. Does not seem overly brittle at all in any of the sections. I have run this print for 3 months now weekly, and up until 3 weeks ago had no problems at all. Now, all of a sudden it is snapping every week in a different place.

Are Ballentyne heads known to be rough/picky with older acetate prints? Splices run real rough through these heads, even on brand new prints.

Could the snapping be caused by:
a. Too much tension at the sound head (the first two weeks it snapped at the sound head after the gate)
b. would improper top or bottom loops cause this to start happening out of the blue. I think I've got a pretty good handle on what size the loops should be. All of the other prints I run go through with no problems.
c. could it be some mechanical malfunction that I would be unaware of due to my limited knowledge of the inner workings of a projector head?

The print WAS being stored in the projection booth, but, the temperatures get WAY to high in that booth for print storage so it has since been moved to my home when not in use.
Could the film have just gotten brittle in that short of a time because of the high temps in the booth? Like I sai, the film appears to be quite flexable and no vinegar detected.

If this is an issue of the film all of a sudden becoming brittle, will film gaurd applied by hand aleviate this problem enough to make this print run without snapping? I've been cleaning with FlimRenew by hand as I do not have a film cleaning machine and niether does the theatre (nor will they spend the money on one, I've asked). Flim renew seems to make it run a bit smoother if applied right before projection, but obviously it doesn't keep the film from snapping. I am wondering if Film Gaurd, applied by hand, may have a more positive effect.

I woould just write it off as a crappy print, but, it seems so odd to me that this just started happening out of the blue, which is why I wonder if operator error/mechanical faliure could be the culprit.

Last question:

Any splices I make seem to separate. I personally use the CPI clear tape. The theatre buys that yellow stuff. Could these faulty splices be the symptom of the high temperatures in the booth where all of the theatre's film is stored?

We are using some generic chinese splicer, which I know is not the best, but, it's all I got and am not sure how a cheap plicer would be the cause of splices separating. (The theater actually has a Nuemade SS but it needs repair, The owners don't understand how important a good splicer is.

Thanks for reading, and i hope I will not suffer to much ridiclue for my novice questions.

John Davey

Posted by Brad Miller (Member # 2) on 06-20-2010, 11:45 AM:

Hi John, I have some advice for you. Please read the rules before creating topics with teaser subject titles. There is no tolerance here for that, as it wastes people's time and makes searching the archives very difficult.

More advice, either you are misthreading the projector, or your projector is in need of serious repair. You probably damaged the print a little bit more each time you ran it. Current movies are on polyester stock and can withstand a projector in need of repair, but older acetate prints can't. Keep that in mind, because that print you are running once a week probably won't be runnable in a month or two at the rate you are going. (This is the same projector that destroyed another acetate print in one pass a year or two ago if I remember.)

Even more advice, this thread will be deleted in 24 hours if the title is not corrected. [Wink]

Posted by Darryl Spicer (Member # 711) on 06-20-2010, 12:55 PM:

Ballantyne projectors can be rough on acetate film if proper care is not taken. Are you experiencing broken sprocket holes? You mention separating splices, does this occur when the film passes through the gate? One thing to remember is polyester film is thinner than acetate film. As a lot of us know here ballantynes like to have unsteady images caused by not enough tension or coupler problems in the intermittent. It is possible that the tension may have been adjusted on the gate to compensate for an unstable image on a polyester based film. This would cause the tension to be excessive on an acetate based film. That can lead to separated splices and film snapping.

Posted by John Davey (Member # 4828) on 06-20-2010, 12:59 PM:

Hi Brad,

Sorry about that. I honestly did not consider that a teaser topic. However, I changed to to what I hope you find to be more appropriate.

As far as the projector, I was afraid it was a projector problem. I just wanted to confirm what I suspected.

Although it is in the same booth as the projector you mention that destroyed a print in one pass, it is a different head. They replaced that head a couple of months back. However, they replaced it with ayet another used Ballentyne Pro 35 head.

I am 99% sure I am not misthreading the projector.

Thanks,
John

Posted by Joe Elliott (Member # 4006) on 06-20-2010, 02:53 PM:

With it breaking at the soundhead, I do not think the following is the problem, but with acetate, it should be mentioned:

Examine the breaks carefully and insure it is not catching a broken sprocket hole. It may not be brittle now, after applying Filmguard, but if it had been run before then and was brittle, a few sprocket holes could have broken.

I started out in a second run house back in the 80's, and after about 10 weeks (between full price house and then ours) we would start to see a few broken sprocket holes (pre-FilmGuard, back when we used Vitafilm, which was prohibitively expensive). If you find any, either trim them back, or as a last resort , put splicing tape over them or cut them out completely.

Posted by Ian Parfrey (Member # 5122) on 06-20-2010, 03:22 PM:

Hi John and welcome aboard.

Just a few questions to clarify your situation.

Are you running platters or change-overs? If change-overs, is it using 6K spools or exchange spools?
Does the "clatter" of the print increase before the film breaks?

The reason I ask is that when running on spools, there is a greater possibility of film breakage (particularly with brittle acetate prints) at the soundhead IF the takeup tension is too high. This will overstrain the sprocket holes and most likely result in film breakage at that point in the film path.

Too much tension can also be due to incorrect platter or tower feed and takeup as well.

My experience with the Pro 35 is that it is highly recommended to keep the gate scrupulously clean - as it is in any machine- as emulsion pile up in the gate also puts the film under too much tension and again will result in film breakage.

Using Film-Guard is a good idea.

Now, to put this bluntly, if you are using crappy splicing tape, then expect crappy splices. There is no way around this. We have all had to deal with shitty tape at one time or another, and if you have crap tape to start with, and then store the print in hot areas, then it is reasonable to expect tape adhesive to liquify and spread causing splice separation and further print damage.

If the owners can't (or won't) spring for decent tape then they really hold their operation AND their patrons in contempt. Good tape is NOT that much more expensive than crap tape- period.

Can you thread your projector and post clear photos of this so we can determine if there is any problem in this area? This will help in finding out where the problem may lie.

If after all your detective work you continue to have film breakage, contact your distributor for a replacement print as the ultimate last resort.

Best of luck and keep us posted!
Cheers
Ian

Posted by Gordon McLeod (Member # 33) on 06-20-2010, 10:00 PM:

check that there is not too much gate tension
there is a set screw that operates an excentric that sets the maximum pressure and acetate is thick than poly based so it could cause the film to have issues as it passes the tight lop in the sound head

Posted by Dan Lyons (Member # 1454) on 06-21-2010, 12:51 AM:

Get a competent tech there straight away. I once owned and rebuilt a Pro-35. There is no reason this machine should harm film; the soundhead is basically a knock-off of the Century soundhead which is one the best around IMO. (though as much as I HATE Kinoton they also have a great soundhead design)

Posted by John Davey (Member # 4828) on 06-21-2010, 01:39 AM:

Dan,

Believe you me, I have begged the owner to get a competent tech in the booth since I started there. He's not having it. He has "a buddy" who "knows his way around these type of mechanical things"

Ian,
We run 6k with a changeover.
The clatter of the print does increases when a slice goes through. It sounds awful (on an acetate or polyester print). I assumed this head was just a noisy head. I have not noticed it clattering excessively before a break though.

I agree with you wholeheartedly regarding the splicing tape. I guess my question would be is the CPI tape crap. I know the yellow tape is crap. If so, what brand of clear tape would any of you suggest?

I only hesitate to use Film Gaurd because I would by applying it by hand. A little goes a long way. The one time I tried to use it by hand I realized the hard way that I DO NOT know the right amount to apply. The flim was supper slick for months afterward.

I will get pics as soon as I can.

There is no chance of a replacement print from the distributor.

Joe,

I at this time I honestly cannot tell if new sprockets are being broken or if the broken sprockets that keep discovering were there before I received the print. I have inspected this print several times and find a broken sprocket here and there that I missed the time before. Nothing constant, just random broken sprockets throughout the print.

Darryl and Gordon,

Anything is possible. As far as adjusting the gate tension, is this a simple process I should consider trying to figure out on my own or should I leave it to a qualified tech? I assume the process for adjusting the gate tension would be explained in the manual for the head?

Thank you guys for all of the responses so far.

I have another "newbie" question regarding threading in frame.
I have been taught/assumed that the view hole above the aperature is what is to be used for threading in frame.

I can only get a changeover on screen in frame about half the time. I thread in frame according to the viewhole above the aperature. But the when I motor down to the correct number on the countdown it is out of frame again, requiring me to adjust my loops so it is in frame again. Am I doing something wrong? Could this indicate a problem with what is called the intermittent gear? I am not sure. Many times, even if it appears to be threaded in frame, it still hits the screen out of frame. I check the leader to make sure it is cut in frame with the film and it usually is. I do not get it.

Thanks again for your time helping a newbie out.

John

Posted by Victor Liorentas (Member # 5272) on 06-21-2010, 01:59 AM:

just a thought. Does the sound drum spin for a while after film is done or at all?

Posted by John Davey (Member # 4828) on 06-21-2010, 02:15 AM:

I do not think there is a sound drum to spin. It a red LED reader.

Posted by Victor Liorentas (Member # 5272) on 06-21-2010, 02:30 AM:

Where the led reader is located is the sound drum!
The rollers at that point,which hold the film in front of the led are the sound drum which is kept in smooth check by a heavy flywheel.
If not for this sound drum the led could not read sound accurately!

I once had a sound drum seize up scratching the film!

Posted by James Westbrook (Member # 3690) on 06-21-2010, 02:35 AM:

It's been almost 20 years since I last dealt with a Ballentine sound head but I believe even with a red-light LED set-up there still would be a sound drum, and that it should be spinning freely.
These are not my favorite machines.

Seems someone else beat me to the punch while I was recalling why we called these infernal machines "boat anchors" in my day.
The pad rollers are also a pain to adjust and may be contributing to the breakage.

Posted by John Davey (Member # 4828) on 06-21-2010, 02:41 AM:

You're both right. It was a confusion on terms on my end. I alway referred to them as tensioners.

They do spin freely and to my knowledge they stop spinning when the film exits the path. I'll double check them next time I go in though.

James,

Even in my limited knowledge, I agree. I do not like these head. They are way noisier than I think they should be. They just seem rough on film in general. I've seen Century heads in action and was much more pleased with what I saw/heard.

Posted by Ian Parfrey (Member # 5122) on 06-21-2010, 02:51 AM:

quote: John Davey
Many times, even if it appears to be threaded in frame, it still hits the screen out of frame.

This could be pointing to the problem.

Is the shoe on the intermittant sprocket adjusted to allow 2 film thicknesses?

Now, assuming the leader IS correctly attached to the print, and that the projector runs poly print stock without dramas, then this COULD point to the intermittant shoe applying too much pressure on acetate stock, catching on the splice and breaking the film.

Granted, there are a lot of "ifs and buts" here, but only by the process of elimination will the problem be solved.

If the Pro 35 is mounted on a Ballantine soundhead, then it is highly likely that there will be a rotating sound drum- and this should spin freely for a few seconds after running.

Again, a photo showing the threaded machine will go along way to helping us help you.

Good luck

Posted by John Davey (Member # 4828) on 06-21-2010, 03:14 AM:

Ian,

Yes, the machine runs poly without any "dramas".

I will definetely look into this. This seems like a very plausable explanation..

I know the intermittent sprocket on this particular machine feels different than the intermittent sprocket on the other machine in our booth. The "teeth" seem more recessed. Where on the ohter machine, when threading you can definetely feel the teeth portruding through the sprocket holes, on this machine, the teeth seem shorter and don't stick out as much through the sprocket holes.

Posted by James Westbrook (Member # 3690) on 06-21-2010, 03:28 AM:

I sympathize with you, John. We are in the same boat in that we have to make do with the projection equipment we have, even if it's less than stellar.
The intermittent sprocket sounds like it needs to be replaced by your description of the teeth being shorter. I would replace the pad shoes on that film trap, too. These hold the film against the intermittent sprocket when the trap is closed.
Sprockets and pad shoes should be available via Strong or your projection parts dealer.

Posted by John Davey (Member # 4828) on 06-21-2010, 03:29 AM:

Just to be sure I know what I am talking about, the intermittent sprocket is the on located directly below the gate, correct?

Posted by James Westbrook (Member # 3690) on 06-21-2010, 03:31 AM:

That is correct.

Posted by John Davey (Member # 4828) on 06-21-2010, 03:33 AM:

tring not to get off topic, but, I have read/benn told before that the intermittent on this head is problematic. James, can you eplxain, in laymans terms, why this is?

Also, while on this topic, I want to see if I have a basic understanding of what exactly the intermittent does. While the top sprocket merely moves the film down to the gate, the intremitent is the one responsible for advancing the film at 24fps and keeping in time wiht the shutter to produce a steady image on screen. Am I in the ballpark at least with this understanding?

Posted by Monte L Fullmer (Member # 2797) on 06-21-2010, 04:42 AM:

PRO35's are really a decent machine if ran and threaded correctly with correct loop sizes-not too big or small .. and threaded in frame at all times. I ran PRO's with Christie AW2's in a twin with no problems, but they definitely needed constant attention for normal operation.

But, they use a flat trap and gate assembly-similar to the Super/E7 of the Simplex. The gate rails are controlled by them little circular springs that are adjusted individually in the gate...and they probably needed to be backed off considerably if this print damage is occuring. You back it off until the picture on the screen begins to show vertical jump, then start to snug down the springs until the jump quits and that is where you want to stop.

The upper and lower sprocket are called 'constant speed' sprockets since they rotate at a constant speed. The Intermittent Sprocket is just that - it rotates intermittently - a quarter turn per complete rotation to stop the film in the trap for a split second so the shutter can cut off the light though the film twice before the next frame pulldown, thus giving you the illusion of motion when viewing the images on the screen

Why the shutter needs to cut the light off twice so you won't see 24 pulses of light per second on the screen, but 48 pulses of light per second which makes this unnoticable to the normal eye.

WARNING! Don't go crazy with that framing lever since that's the major problem with that machine: for behind that lever is a coupler that couples the intermittent sprocket shaft to the starwheel shaft since the shutter doesn't compensate when needing to frame - just the sprocket compensates via that danged coupler. And that coupler, made of nylon, loves to wear out and it's a pain to replace.

Wonder if that danged intermittent sprocket coupler is worn ..

-Monte

Posted by James Westbrook (Member # 3690) on 06-21-2010, 05:05 AM:

What Monte just said.
The framing assembly and the coupler is the weakness on that intermittent. Instead of one long sprocket shaft, we have 3 pieces connected together. More complexity brings more problems.

Posted by Scott Norwood (Member # 30) on 06-21-2010, 06:20 AM:

You say that the film snaps at the soundhead. Are you using floating-hub reels for takeup, and is your takeup tension adjusted properly? Is it possible that the film is jumping a sprocket or two across the holdback sprocket at the start of the reel, causing too much tension in the soundhead?

This would not explain out-of-frame starts, however.

Posted by Gordon McLeod (Member # 33) on 06-21-2010, 06:45 AM:

Down load the manual and there is a section on gate tension

Posted by Kenneth Wuepper (Member # 1174) on 06-21-2010, 06:57 AM:

Operator caused "out of frame starts" are the result of improper threading of the projector. The intermittent sprocket must be locked in the position for the shutter to open and image to be projected.

Simply placing a finger on the intermittent and turning the inching knob or motor shaft to feel when the rotation stops is recommended. At this point the leader is threaded in frame in the viewing port.

Advancing the film a few frames by hand will confirm framing after the entire machine is threaded.

If there are splices in the leader between the threading point and the picture, they must be confirmed to be in frame or the leader can cause the projected image to be out of frame. This can be caused by out of frame repaired breaks during the "motoring down" prior to starting the projector.

KEN

Posted by Richard P. May (Member # 3598) on 06-21-2010, 09:47 AM:

When threading the projector, are you checking to be sure the intermittent sprocket is in its "rest" position? If it is in the "pulldown" position, you will almost always end up with the picture being out of frame when the intermittent is at rest.
I have always made it a habit to put my finger on the sprocket (motor off, of course), and turn the motor over by hand until the sprocket moves, then comes to rest.

DM

Posted by Monte L Fullmer (Member # 2797) on 06-21-2010, 12:49 PM:

I do the same: rest my finger on the sprocket while I turn whatever device (inch knob, motor flywheel, et.al.) by hand to feel the sprocket come to rest before threading so I'm always in frame on a start.

And, it's amazing how the majority of booth personnel don't know this procedure, or they simply don't care to know if shown this procedure.

True though, is slip reels used for takeup, or solid reels if using 6k reels ...

-Monte

Posted by Joe Elliott (Member # 4006) on 06-21-2010, 03:09 PM:

I have my guys not only making sure the intermittent is locked, but I drum into them to check the framing 3 times. Advance it by hand while threading, check it again when motoring up (we use a Mylar leader before the regular leader, and they are to thread on the Mylar, and motor up to the regular. That catches potential problems BEFORE start.) At start time they are to strike the lamp and advance by hand a few frames, again checking framing. Then they start it. That way there is no excuse to start out of frame.

Posted by John Davey (Member # 4828) on 06-21-2010, 05:30 PM:

Monte and James,

Thank you for the explanation. That's how I thought it worked but wanted to be sure.

My question is: if I adjust the film gate tension for an acetate print, is it going to affect the way the machine handles ploy prints? Ohter than this one show a wekk, all of the film this theatre runs is poly.

Scott and Monte-
We use both types of reels in the booth. Floating hub and stationary hub.
After all of the info I've gotten out of this thread, I think we are running too much torque on the take up and is the reason it has snapped at the sound head. However, the sound head is not the only place it has snapped, so that's not my only problem.

Monte, Richard and Joe,

I had no idea about the intermittent having to be in a certain position. It makes complete sense now that it has been brought to my attention. I will be implimenting the technique you guys have suggested and will implore the other manager/projectionists to do so as well. Monte, when you say "inch knob" are you referring the the framing knob? if not, where is this "inch knob"

Guys, once again, you have given me a world of help. Thanks so much

Posted by Brad Miller (Member # 2) on 06-21-2010, 05:37 PM:

John,

Here is some of the best advice you will ever get...find someone who actually knows what he/she is doing to show you how to operate that booth, then get everyone trained. Not trying to be rude, but the questions you are asking are so simple they are "first day of training" issues. The fact you are running one-of-a-kind/last existing prints is downright frightening.

The "threading 101" document in the tips section here is on different equipment than you have, but would at least give you an idea of what these guys are trying to explain to you.

Is there anyone on here within a reasonable driving distance from John that might be willing to let him come see their booth and watch for a day or two? (Ideally someone who has been doing this long enough to have handled acetate prints back in the early 90s or before.)

Posted by John Davey (Member # 4828) on 06-21-2010, 06:02 PM:

Brad,

I do not disagree with you. I would LOVE to be trained by someone compitent. I do understand the questions I am asking are first day of training type of stuff. I understand you're concern about someone like me running one of a kind prints.. I've acually read the threading 101 , which is where I learned about threading in frame. I was not given that knowledge when I started at the theatre. Everyone just threaded and framed it when it hit the screen, which looks god awful.

I seem to be the only one at my theatre who has enough passion for the job to try to learn to do it right. However, the few things I HAVE picked up, the other managers did listen to me and to my knowledge, and did implement the procedures I suggested (i.e. threading in frame)

If there was someone who wanted to let me hang out, or wanted to come see what I have going on at my theatre, I'd be more than willing. I od not want to trash a print anymore than the next guy.

Posted by Jeremy Weigel (Member # 4208) on 06-21-2010, 08:06 PM:

quote: John Davey
I had no idea about the intermittent having to be in a certain position.

I just took a look at the manual for the Pro 35 and unfortunately they left this part out, so it is understandable that any one simply going by the manual would have no idea how to truly thread up in frame 100% of the time. (Not saying that you went by the manual, but perhaps the operator(s) that trained you were/are simply going by the manual).

As to the "inch knob", this refers to whatever means there is to manually turn or "inch" the sprockets. Usually a knob attached to constant feed sprocket(Christie) or simply turning a flywheel on the projector motor (most every other brand).

Posted by Jeremy Weigel (Member # 4208) on 06-21-2010, 10:00 PM:

quote: John Davey
We use both types of reels in the booth. Floating hub and stationary hub.
After all of the info I've gotten out of this thread, I think we are running too much torque on the take up and is the reason it has snapped at the sound head. However, the sound head is not the only place it has snapped, so that's not my only problem.

Be sure you're using the floating hub for take-up (if you're not already). This will lessen the torque upon start.

Posted by John Davey (Member # 4828) on 06-29-2010, 04:21 AM:

JUst wanted to thank everyone for all of the help. I do not know if I've worked out the print breaking problem yet(gonna give it a test run afterhours sometime this week. We ran it digitally last week and it looked like hell). However, I have not had one single out of frame start or changeover out of 4 shows I've run since learning of the inch knob. So, thank you. Also had a trained tech in the booth this week to repair a rectifier that went out, asked him baout the possibility of the intermittent sprocket being bad in the one machine. He said, no, it's not bad, just a newer make of sprocket than the other machine.