Film-Tech Forum ARCHIVE: Speco MUT and cores

This is topic Speco MUT and cores in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Paul Cunningham (Member # 501) on 01-01-2001, 05:58 PM:

Just curious how other people handle making up or breaking down prints on cores with the Speco's. We use a short piece of threaded rod in the innermost hole which prevents the core from spinning freely.

Paul

Posted by Ian Price (Member # 14) on 01-01-2001, 06:43 PM:

We have 5 Specos here at the Rialto.
We spin the film off on to 6,000 foot reels then I break them down at our Kelmar make-up table.
I use a split reel to put the film back on cores.
This frees the projectionist up to break down the next film.
If we have quite a few films to break down, we just keep doing the 6,000' reel/make-up table thing.
We can break down pretty fast this way.

Posted by Brad Miller (Member # 2) on 01-01-2001, 08:51 PM:

On a SPECO, I prefer to use a Goldberg split reel and a drill. Drill yourself a hole in the reel flange that lines up with the hole in a 4 inch core (make sure you have the core properly positioned before drilling). Then I just drop it on like a regular reel. I've never been pleased with the wind on a core from a rewind bench.

Posted by John Eickhof (Member # 323) on 01-01-2001, 11:43 PM:

Brad's idea sounds to me like it would work well, however I have always removed film onto reels and rewound onto cores at the bench! A good rewind with a 'tight-winder' or a decent
drag clutch will give 'lab quality' stacks on cores! In fact that's how they've done it at the labs and studios forever! A good 'tight winder' will allow you to place film on a core without a split reel (or trailer flange)
Happy new year to all! And happy B-day to Film Tech! John

Posted by Michael Barry (Member # 237) on 01-02-2001, 01:18 AM:

I wish I had pictures, but where I've been working recently, I've been using the Cinemeccanica 35/70 electric rewind bench. Although not cheap, this is a really spiffy, solid rewinder. (I've never seen a Kelmar, though.) The 'back' tension can be set so that tight rewinds onto cores are possible. Instead of a split spool, we've been using 6000' open plates with a spindle/drive pin arrangement. This sits on a 1/2 inch spindle. Place the core on this and you're set to go. Works very well!

Posted by Greg Mueller (Member # 17) on 01-02-2001, 08:08 AM:

Hey John. How many pounds or ozs of tension is there on a "tight wind"? I was just wondering how much strain the film can take before it breaks or stretches.
Thanks

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Greg Mueller
Amateur Astronomer, Machinist, Filmnut

Posted by John Pytlak (Member # 331) on 01-03-2001, 06:59 AM:

SMPTE Recommended Practice RP 106 specifies "Film Tension in 35-mm Motion-Picture Systems Operating Under 0.9m/s (180 ft/min). It says: "Film tension under normal operating conditions shall be 1.7 to 4.4 N (6 to 16 ozf).

Polyester film can withstand quite a bit more tension than this without stretching or deforming, but it is still a good idea to use a "tight wind" buildup roller rather than tension alone to wind a tight, even roll on a core. A "tight wind" uses a weighted or spring-loaded undercut roller to "pressure wind" a smooth tight roll.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Gordon McLeod (Member # 33) on 01-03-2001, 02:36 PM:

A cautionary note on tight wind arms and rollers make sure the print isn't photoguarded our you will be in for a interesting cone shaped suprise

Posted by John Pytlak (Member # 331) on 01-03-2001, 02:46 PM:

"Coning" or "Dishing" can occur if the thickness is not perfectly even across the width of the film. Even a few microns of thickness difference adds up over several hundred convolutions of film when wound tightly, giving you a bowl-shaped roll.