Max run time to fit on platter?

[Michael Coate]

What is the maximum running time that a 70mm print with a magnetic soundtrack can be and still fit on a platter?

[Apologies if this question has been previously asked and answered. If it has, please answer this with a link to that thread.]

[Steve Guttag]

It's not a finite answer as different platters are constructed differently with different ID and OD. For magnetic film, about 3.25-hours on a 52" deck is pretty much going to require creative affixing of the tail. Depending on the platter in use and how it regulates speed, on take up, it could be getting a bit dicey out there too as the decks are moving a bit slow. The platter has to have enough torque to handle the full deck but not jerk the little bit of film left when it is just that outer ring around the credits.

The longest I've personally seen on say a Christie AW3 was "The Right Stuff" and the suction cups that Christie suppled wouldn't fit because there wasn't enough "deck" left. That film was just under 3.25-hours.

[Jim Cassedy]

Fortunately, 98% of the 70mm magnetic sound prints I've shown were done with reels & change-overs, but on the two occasions I've had to run one off a platter, I discovered I had to make a slight adjustment to the AW-3 speed controls when running the 70mm mag because of the increased weight of the magnetic tracks plus the fact they were printed on the older acetate base film stock, which also weighs more than the newer, mylar film. The added "stiffness" of the mag tracks also made the 'brain fingers' which regulate the platter speed, respond slightly differently, although the problem, as Steve pointed out, was most pronounced when the platter had to deal with the circumference near the end of the print.

[Leo Enticknap]

The only place I ever had to platterize 70mm had a Kinoton ST-200. I hated the initial ramp-up, because it would start very slowly, then overspeed, and I'd have to dash over and use my hand as a brake to slow it down to prevent a brain wrap. Once it was up to a stable feed speed it was rock solid for the rest of the movie, even with Titanic (the longest feature I had to play in a single roll, which only just fitted onto the deck). But the ramp-up was scary. I'm told that Cinemeccanica platters were even worse.

[Steve Guttag]

Something sounds amiss if the Kinoton platter didn't ramp the speed properly. That's sort of their thing. They start the platter at the proper speed for ID of the ring. It sounds like it wasn't resetting to the show start speed. The platter did have the proper motor-run signal from the projector, didn't it?

[Sascha Roll]

I second Steve - Kinoton platters (old and new) usually start up extremely smooth.

[Michael Coate]

So, consider something like Spike Lee’s “Malcolm X,” which has a running time of 202 minutes (i.e. 3 hours 22 minutes). Do you think it’ll fit?

[Steve Guttag]

It's entirely possible but again, you are going to have to be creative on how you hold the tail and depending on the platter make/model you might find things dicey when you get out that far.

[Brad Miller]

Geez, how to secure the tail? Hmmmmmmm.


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[Steve Guttag]

A couple of things...1: did that exist when The Right Stuff or Malcom-X were in release. 2: what is the longest striped magnetic 70mm (acetate) have you can you run on an AW370?

[Gordon McLeod]

I never had issues with long 70mm prints on the ORC platters they heald alot of film and if setup right were very stable The only failure point was eventually the motor brushes and the servo pots

[Marcel Birgelen]

I remember running Malcolm X at the university in 70mm way back. It was just a single show, so we ran it in changeover, since we didn't even try to fit it on the platter as we had doubts it could comfortably fit on there.

I guess those tail-protectors are a relatively new invention , I doubt they were around when The Right Stuff was in release, at least not with Film-Tech branding on them.