Film-Tech Forum ARCHIVE: Millennium and 5-star threading

This is topic Millennium and 5-star threading in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=009943

Posted by Paavo Mardi (Member # 4962) on 06-12-2009, 07:14 AM:

I have question about threading style I saw a few days ago.
Shoudnt there be a small 2-3 perf loop between the after-intermittent roller (I´m sorry, I dont know the exact term in english) and sound durm. The dumper roller was pulled pretty tight. I personally think, if there is no loop and the sound should switch to analog, the sound will be "blurred".
Or does it have something to do with the 5-star sound-drum design? I have read here that the 5-star sound-drum tends to leave a visible mark on the print. The pressure roller tension was set pretty low so you could turn the pressure roller almost without moving the sound-drum itself... So probably thats the reason they dont make the loop, because otherwise it may scratch the print?
When I asked the projectionists why they are threading like that they said that so they were teached to thread.
I personally havent worked on Millennium and 5-star.

Posted by Kenneth Wuepper (Member # 1174) on 06-12-2009, 07:53 AM:

Paavo,

You are correct in that there needs to be some loop between the constant speed sprocket and the sound drum. I believe that the manual calls for 2 sprocket holes of slack.

This small amount of loop allows for smoothing out the changing of speed from the machine to the sound drum. The sound drum turns with a lot of inertia due to the weighted wheel that it drives. Small changes in speed are evened out by the inertia of the sound drum assembly.

Too tight threading of that area of the projector can add scratches to the film when there is a small speed change in the machine and the tight film is dragged against the sound drum area rather than coasting by the inertia of that part of the machine.

KEN

Posted by Steve Guttag (Member # 268) on 06-12-2009, 08:08 AM:

Since this is a 5-star soundhead...no, there is no slack between the projector and soundhead.

When setting the tension on the film between projector and sound, pull up on the film in the 5-star soundhead and note the damper roller arm...keep pulling until the arm reaches its stop, then back off at least one full perforation. However don't back off more than 2 perforations.

In a 5-star, the return spring on the damper arm sets the tension and the damping fluid stabilizes outside vibrations.

It works so-so. One can work on the spring on that arm to make it work better....often they are set too tight. The spring should not cause the pinch roller to lift off of the sound drum. In fact, when I'm done with the spring, the film normally appears just slightly slack after everything has come up to speed and stabilized. Sorry, there is no spring force spec that I'm aware.

Steve

Posted by Robert E. Allen (Member # 1351) on 06-12-2009, 03:10 PM:

I hope I'm understand you correctly. All projectors and soundheads thread basically the same. You must have a loop above and below the gate/trap or the film will be torn apart. after the loop coming off the intermittent there is no slack going over the sound drum. There is some slack going from the sound drum to the holdback sprocket (the bottom sprocket) but it isn't all that critical. Usually just enough to prevent any strain on the film.

Posted by Brad Miller (Member # 2) on 06-12-2009, 08:37 PM:

For the record, Steve's post is the only accurate one here. The 5 star threads different than the traditional SH1000/RCA type of soundheads that Ken and Robert are familiar with.

Posted by Robert E. Allen (Member # 1351) on 06-12-2009, 09:48 PM:

Thanks Brad. Never too old to learn are we?

Posted by Joe Redifer (Member # 3) on 06-12-2009, 11:47 PM:

I really, really hate those SH1000 soundheads. I once got a call from a theater that was wondering why all movies played in a certain auditorium were scratching. I go over there and check it out and the base side of the film is rubbing against the pad roller of the upper feedback sprocket in the soundhead as it comes off to form the loop. I have no idea why this soundhead even needs a loop since the film is just running between two constant speed sprockets with no intermittent motion whatsoever and no possibility of tension change. It makes even the Simplex 5-Star soundhead look like a good design (which is certainly isn't, but it is a definite improvement). Anyway I straightened out the pad roller and told them to make that particular loop smaller. No more scratches.

quote: Steve Guttag
keep pulling until the arm reaches its stop, then back off at least one full perforation.

At least one? At least? You mean I can back off a half a perf? [Wink]

Posted by Monte L Fullmer (Member # 2797) on 06-13-2009, 12:46 AM:

quote: Joe Redifer
I really, really hate those SH1000 soundheads

Sorry you do, but I think that they are the best heads ever manufactured - Fluid dampened scanner drum flywheel, smooth ramp up speed,et.al.

Simplex, when they WERE Simplex, knew how to build projectors...

... you just gotta know how to work with them. This new generation just don't know how things are as we know it.

(Like on a side topic: I watched a new employee, who worked with projectors before, didn't know the term "setting the intermittent sprocket" meant even though she wondered on why some show starts that she was out of frame even though she knew that she threaded in frame...til I showed her. She was totally embarrased on how simple it was - and ashamed that no one where she worked at, never showed her about this threading procedure since they, themselves, were never shown...)

Yes, I'm guilty on lacing up 5-Stars wrong with the snub roller arm inbetween the two limit stops on the mounting bracket (which caused "film walk" across the scanner drum until the drum ramped up to speed and smoothed things out on startup..) until Steve posted this correction a couple of years ago.

I've then corrected my procedure and it does make perfect sense on why this procedure from his post is needed. Since then, this is how I train and retrain booth operators on proper 5-Star threading procedures ...and say "goodbye" to "filmwalk" across the scanner drum.

thx-Monte

Posted by Brad Miller (Member # 2) on 06-13-2009, 01:04 AM:

You must be joking. The SH1000 and 5 Star are the two WORST soundheads ever designed. Their design has little concern for the care of the film being ran through it.

Posted by Tim Reed (Member # 137) on 06-13-2009, 01:18 AM:

FWIW, in the days of the SH-1000, most if not all reproducers had felt rollers that pinched the image area of the film against the impedance drum.

Given a choice between an SH-1000 and an RCA 9030, though, I'd take the SH-1000. Mainly because the gearboxes were more reliable, IMHO (although, I never really liked the butterfly-type latching mechanism).

Posted by Monte L Fullmer (Member # 2797) on 06-13-2009, 03:05 AM:

Oh, I agree with the 5-star being the worst-the way they did the drum/main drive shaft bearings in not being pressed in the frame..

But can see why they made it compact compared to the "4-star" - so the machine can get closer to the port window. But heard that the motors on the 4star were becoming extinct.

... they should have kept the felt roller...but try to keep them dry from oil was another trick..

Now, a horrible head was the Motiograph Mirrophonic 7400 - that coupled snap starts due to no flywheel, that large single sprocket where a lot of operators would wrap the film all around the sprocket instead of the required front loop..

Posted by Steve Guttag (Member # 268) on 06-13-2009, 06:52 AM:

In the day of the SH-1000, all theatres were changeover (ah...the good ol days)...thus the second sprocket to isolate the sound scanning from any flucuations from the take up.

As for being one of the worst soundheads...no I don't agree there...its biggest flaw...as with all Simplex/RCA designs, it has an image area contact part...the pinch roller. That should not have persisted this long. BTW...the felt rollers will track Dolby Digital better than the rubber ones...which bounce a bit during normal operation.

Steve

Posted by Joe Redifer (Member # 3) on 06-13-2009, 10:46 AM:

I'm curious as to how at any point in history someone could have thought it a good thing to have something that contacts the image area like the ol' felt/rubber pinch roller. It should have never been designed like that in the first place. The fact that it is still like this to this very day reflects very poorly on Simplex and Strong.

Posted by Scott Norwood (Member # 30) on 06-13-2009, 10:53 AM:

quote: Joe Redifer
The fact that it is still like this to this very day reflects very poorly on Simplex and Strong.

No, it reflects poorly on the people who keep buying the product. The Century soundhead doesn't have this issue, nor do Kinoton, Cinemeccanica, or pretty much any other brands.

Posted by Mark Gulbrandsen (Member # 72) on 06-13-2009, 10:56 AM:

quote: Scott Norwood
No, it reflects poorly on the people who keep buying the product.

Thats always been my though too Scott... and even more so as to the stupid company that kept producing it.

Mark

Posted by Paul Mayer (Member # 355) on 06-13-2009, 11:27 AM:

Just reflects the attitude of the time, "We sell all we can make, and we have a huge backlog - no need to change anything."

Posted by Mark Gulbrandsen (Member # 72) on 06-13-2009, 04:47 PM:

HA! They don't any more....

Posted by Joe Redifer (Member # 3) on 06-13-2009, 07:31 PM:

Then why did they change the gate and trap design but not the soundhead design? Don't say "the turret!!!11!!". I have worked with many Simplexes with a turret that have the old style gates.

Posted by Brad Miller (Member # 2) on 06-13-2009, 07:51 PM:

Joe, they didn't change it because in their minds, film damage is perfectly acceptable.

Like I've said for years, any projector design that requires part of the machine to come into direct contact with the picture area (and in this case the EMULSION side immediately after it has been softened by the heat of the lamp) is a shitty design. Adding a leaky oil bath to the design makes the disaster even worse.

Get a Century...or a Christie...or a Kinoton...or a Cinemecannica...or any of the other GOOD machines out there. Dump the Simplexes into Phil Hill's house. He doesn't seem to know any better. [Razz]

Posted by Paavo Mardi (Member # 4962) on 06-14-2009, 05:05 AM:

quote: Steve Guttag
When setting the tension on the film between projector and sound, pull up on the film in the 5-star soundhead and note the damper roller arm...keep pulling until the arm reaches its stop, then back off at least one full perforation. However don't back off more than 2 perforations.

Pretty clever design on that 5-star. You can thread it much more faster. It´s not that easy to make a perfect loop before sound drum on that long film path if there was no damper roller.

quote: Steve Guttag
...its biggest flaw...as with all Simplex/RCA designs, it has an image area contact part...the pinch roller

It does´nt seem to be that bad. I have seen prints with lines on the picture area that are probably made by these rubber rollers. They are not visible on the screen.

I wish I had these Millenniums in my booth. We have the famous Simplex Apology projectors. Apogees dont have the pinch roller and we have to speed up the sound drum flywheel by hand, otherwise the trailers get scratched. Apogees are really bad projectors, but that´s another topic...

Posted by Joe Redifer (Member # 3) on 06-14-2009, 10:42 AM:

quote: Brad Miller
Get a Century.

But... but Century projectors don't have the Very Kind to Film sprockets! In fact, Century sprockets can be downright rude!