Film-Tech Forum ARCHIVE: Threading question

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Posted by Erick Ojeda (Member # 216) on 12-12-1999, 11:03 AM:

Hi everyone,

I was reading the Pet Peeves topic when I came across George Roher's pet peeve on operators who thread by throwing the leader onto the floor, threading the projector, and then lacing the platter. When I was trained, I was told to throw the leader onto the floor, thread the projector, and then walk the leader over to the platter. I know doing it this way will most likely pick up dirt onto the leader, which then will go onto the first trailer, but this is the way I was tought how to thread. I've read and heard about threading the platter first, and then the projector, but how is this done, and what are other good ways to thread? Thanks for any replies.

Erick

Posted by Sean McLemore (Member # 260) on 12-12-1999, 11:31 AM:

I've Always threaded through the platter, then pull just enough slack though to thread the projector. This really is the best way. Besides the first trailer getting dirty, it keeps the whole projector clean, which keeps the enitre print clean.

Posted by John Walsh (Member # 168) on 12-12-1999, 01:04 PM:

Personally, I dislike the method of pulling the film all the way to the platter, then going back to thread the projector. Of course, it can be done (keeping the film clean) but you must be more careful. While people start out being careful, they end up allowing the film to drape onto the floor, or the platter unexpectedly takes up the film when you are not ready.

I start by pulling the 'head' end to the projector. Then pull the film down to "10" creating big loops, which I hang on the dowser handle. Thread the projector, then holding onto the loops (but letting them pay out as you go) thread the platter.

I have new people pay the film into a small, clean office-type trash can, until they get used to handling film.

Anyone who just pays it onto the floor deserves coal in their stocking.

Posted by Erick Ojeda (Member # 216) on 12-12-1999, 01:39 PM:

John:

I like your method of threading. Also, having new employees place the leader into a small clean office style trash can is a good idea. I will have to remember that. Trust me, I never really understood the different ways to thread. I was tought one way, which was placing the leader onto the floor, and I have done that method ever since, but after reading this forum, my mind has opened up to new, and better ways to operate the booth. Thank you for your reply.

Erick

Posted by Brad Miller (Member # 2) on 12-12-1999, 02:51 PM:

All of my trainees are taught to thread the film from platter...bypassing the projector...and back to platter. This keeps the film off of the floor.

Next they place the film onto the last sprocket (holdback sprocket) in the soundhead and THEN pull a bit of slack from the takeup (to start the takeup platter) while they thread the film through the failsafe and under the lower arm roller.

From that point, the projector is threaded UP (literally), pulling any necessary slack from the top (feed platter).

The film NEVER touches the floor when threaded in this manner and it is significantly faster than any other method. Of course, newbie projectionists pick this up right away as they don't know any different, but the guys who've been around the booth for years and years often have difficulties threading in this manner. Some people just seem to think the projector must be threaded in the direction of film travel.

An acceptable solution for those who insist on threading down is to keep a clothespin beside each projector and once the film is threaded platter to platter, clip the film to the base of the soundhead (to keep it off the floor) while the projector is threaded.

Also, the trick in threading platter to platter and keeping the leader from hitting the floor is to NOT thread the lower arm roller. The film must be brought from platter to the upper magazine roller and then straight back to the platter. This will keep the film far away from the floor.

Posted by Gordon McLeod (Member # 33) on 12-12-1999, 03:18 PM:

I always start by threading the intermitent sprocket first putting Picture start in the gate and then going upwards through the gate upper loop sprocket and penthouses and then downwards through the optical head ensuring the diamond is on the sound head If you come across a projector you have never seen you can always thread it that way correctly

Posted by Gordon H. Bell (Member # 261) on 12-12-1999, 05:26 PM:

Another method I used for many years of threading film from platter to projector and back to platter - pull enough leader from the platter to thread the projector and soundhead. The slight excess that would land on the floor can be draped over a handy part of the mechanism. When threading is finished there should be enough leader available to wrap once or twice around a film core mounted on the take-up reel shaft. Start the projector motor and wind about 25' (or whatever length you need) of leader on to the core. Switch off the motor and let the projector COAST to a stop a few frames ahead of your start mark. Remove the core and leader and, unrolling as you go, thread though the rollers to the take-up table. There should be enough leader left on the core to wind 1 1/2 to two times around the take-up ring. Back to the projector and manually turn down the few frames needed to place the start mark in its normal position.
Initially it takes a little playing around to get things exactly right, after which it can be done almost with your eyes shut (except for framing!) Worked well for me, even with 70mm.
Perhaps I was lucky because all my projectors were equipped to handle take-up reels which is not always the case these days.
This is my first post and after lurking for almost a year I want to express my appreciation and thanks to Brad Miller for bringing this site into existence and to all of you who have provided such interesting and educational reading with your postings.
I thank you all

Posted by Scott Norwood (Member # 30) on 12-12-1999, 06:50 PM:

Regarding "threading UP": I tried that once (with reels, not platters...same idea, though) and found it to be totally counterintuitive. There's a bigger problem, though...normally, I'd start by turning over the projector by hand to get the intermittent in the dwell position, then thread the intermittent sprocket first...that way, I can make sure that both the upper and lower loops are the proper size...when threading "up," won't the size of the lower loop vary each time the projector is threaded? That doesn't sound like such a good idea, although I am much more sensitive to sound sync than most people will ever be....

Posted by Gordon McLeod (Member # 33) on 12-12-1999, 06:54 PM:

I really don't like the concept of the projector motor being used to run film down.
Starting and stopping puts undue strain on the gear train and belts.
Usually the time a gear will strip or a belt break is on startup.
Thats is what the inching knob is for

Posted by Erick Ojeda (Member # 216) on 12-12-1999, 08:04 PM:

Brad:

I'm going to interpret what you said, so see if I understand it right. The film goes from the feed out platter, unto the top roller above the projector, back to the take up arm on the platter, and to the take up platter. After hooking the leader to the ring, place the take up arm on the platter to the ready position, and turn the knob on the take up platter to rewind. Now, take the film, and place it in the last sprocket in the soundhead, pull the slack that will be going to the take up platter while threading the failsafe, and bottom roller below the projector. The platter will take up the leader, and now just thread the projector, so once I'm done threading, and make sure the projector is threaded correctly, I can just hit the start button on the automation. I believe this is how you explianed it. I have one more question. When I thread the platter, and turn the knob on the take up platter to rewind, wouldn't the platter begin to start taking the leader before I can get back to the projector, which then I wouldn't have any slack to work with?

Posted by Joe Redifer (Member # 3) on 12-12-1999, 09:05 PM:

Threading "Up" is a bit difficult on my projectors (Christie P35GPS) because of the giant flanges on the sound drum arms. It is very difficult to get the film in that way. Brad has older Christies which are easy to thread "up".

What I do is thread platter to platter, then take the film and put it on the bottom holdback sprocket (just like Brad) and close the pad roller. Thread the failsafes and tug a bit to take up (engage) the platter. After that I simply thread down like normal. The film never touches the floor and it is very quick to thread that way.

Just as long as the leader (or film) never touches the floor you are safe. That's what matters.

I agree with Gordon about motoring the leader. Our automation used to require that (Christie CA21) but I changed a few things and we no longer have to motor anything. Saves tons of time while threading and the belts in the projectors last longer as well.

Posted by Paul Konen (Member # 41) on 12-12-1999, 11:07 PM:

I always thread up on my Christies (P35GPS). I do like others, payout platter to top roller on projector back to platter takeup.
Pull some slack to start threading, failsafe first, the bottom constant speed roller, close pad roller and then engage takeup arm on platter. Continue threading up. Once inside gate, frame it, close gate and then turn hand crank until intermittent wants to turn, open pad clamp on middle roller and and pull film until it contacts open pad, close pad, adjust sound head tension and then continue through the top of the projector.

In doing this, I have found that I create very consistent loops.

Paul

Posted by John Walsh (Member # 168) on 12-13-1999, 03:32 PM:

Like everything else, threading platter to platter may work better in your particular situation. Any method that keeps it clean and does'nt jerk or pull, etc. is OK.

'Threading backwards' from bottom to top does take some practice. I have done it, with a Christie AW5 and a Cinemeccanica V9, and found it very easy to do with that combination. A V9 is usually a very 'open' machine with no doors and lots of room. A 'closed' projector (like a Simplex or Century) might be harder to get used to. So, I'm not totally against it.

Now if Brad, (or just about anyone who posts here) wanted to do something in a particular way, there would be no problem. Everyone here probably has a real interest and knows what they are doing, or are willing to learn.

But, the people I train not only know nothing about projection, they _don't want to learn_. When they first start working, it is implied to them that the box office and candy stand are the most important, and projection is just another part of the theater, no more or less important than the bathrooms. And, I get about 4 days to teach them. They get very unhappy; not only do they find it is harder then the other stuff (and they feel mis-lead), they don't get any extra money.

Then, after barely knowing anything, they get dropped-kicked to another theater with different equipment, where they now must train others. The platter they are now using may be more sensitive and take up the film when they are not ready, the projector's different, the film may run up against where oil collects, etc.

I feel I need one method that stresses basic film handling, etc.; that will work with just about any projector/platter combination (even reels); that they will remember well enough (after not wanting to learn it in the first place) to teach others after being 'shipped-out.'

So, I find that 'top-down' (actually, Gordon's method: intermittent sprocket first) works best. I find that for new people, it is more intuitive.

I tell them; When you get good at the basics, then you can do whatever you want.

Of course, YMMV.

I also make sure they learn to thread such that, with only a few turns by hand, the film is at the right 'start' frame (for us it's "10"). I get real upset when someone 'gooses' the projector down with the motor. I know a guy who killed a AAII that way. (Although, to the AAII's credit, it took almost 10 years!)

Posted by Michael Cunningham (Member # 210) on 12-14-1999, 10:27 PM:

Although I like the idea of threading "upwards" to keep film off the floor, I am at a loss as how to take slack out of the leader after threading the soundhead holdback sprocket. We use Strong platters on the non-operator side of the projector. These have a vertical variac system to control take-up speed. If I tug on the leader enough to raise the variac beyond the cutoff point and start the take-up platter spinning, the platter won't stop quickly enough to prevent the variac rollers from slamming into their counter parts at the top of the slide. This is hard on the mechanism and throws off the calibration of the variac. Any suggestions?

-Mike

Posted by Brad Miller (Member # 2) on 12-15-1999, 02:13 AM:

Yup. Get Christie platters!

Assuming the money people won't want to shell out the bucks for AW3s, then you can pre-tug on the leader BEFORE you place the film on the holdback sprocket, feeding it a bit more until the damn thing tops. Not much else you can do with that short Strong elevator. Why they don't extend that another foot is beyond me.

Posted by Scott Ribbens (Member # 180) on 12-15-1999, 02:39 AM:

To take the slack up on your Strong, it is a simple matter of quickly pulling the slack past the switch that turns the variac off at the bottom, the cutoff point that you are refering to, and without stopping there, continue to pull until you have the accumulator just past the variac off position at the top. Then let the slack payout of your hand in a slow, even manner, until all of the slack has been taken up.

The trick to this is pulling the film fast enough to get the accumulator to the top of it's travel, without the variac having enough time to get the platter deck spining at any great speed (not hard to do at all). Once you get the knack for it, you can take the slack out of the film without even thinking about it. It takes less then 2 seconds to do, and has worked well for me for many years.

------------------

Scott