posted April 06, 2013 12:28 PM
Greetings everyone! I have an Elmo 1200HD and when I get a film (3-reeler) that is mounted on a 800ft metal reel and go to rewind the film the film rewinds back lop sided on the reel and the film is very loose. My take-up reel is an Elmo 800ft plastic reel so do I maybe need to use an 800ft metal reel for the take-up reel when I run a film on a 800ft metal reel? I do have an Elmo 1200ft reel that's aluminum and perhaps I could use that one to?
Posts: 996
From: Kvinnherad, Norway
Registered: Oct 2009
posted April 06, 2013 04:17 PM
Sounds very odd... I have the exact same setup, ST1200 with 800 ft Elmo take-up reel in plastic, and it's never been an issue.
In fact, I screened "The Lost World" last night, on 2x800 metal reels, and there was no issue.
-------------------- Well who’s on first? Yeah. Go ahead and tell me. Who. The guy on first. Who. The guy playin’ first base. Who. The guy on first. Who is on first! What are you askin’ me for? I’m askin’ you!
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 06, 2013 05:23 PM
Maybe since the plastic reel is lighter it has less inertia than the metal one and it speeds up and slows down more easily.
That pulsation of the film during rewind is the the film tension rising and falling and that might lead to an uneven rewind.
-------------------- All I ask is a wide screen and a projector to light her by...
posted April 06, 2013 05:37 PM
Steve, Instead of rewinding the film back on the metal reel I rewound it on an Elmo 800ft plastic reel and the film rewound tight like it normally does and it did not rewind the film lop sided on the plastic reel so it has something to do with the metal reel?
I'm going to try and use a 800ft metal take-up reel with the 800ft metal film reel next time and see if that resolves the problem otherwise it remains a mystery? RS
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 06, 2013 05:51 PM
Maybe it just means there is more going on here than meets the eye.
You have two reels operating at different speeds with film stretched between them that has some elasticity (like a spring). So you have possibilities of all sorts of resonances and maybe some surprising results. (Remember that bridge that shook itself to destruction?) Maybe changing the reels around is enough to alter the equation.
It could keep a Mechanical Engineer fascinated for days, but I'm Electrical and besides, I'm OFF today!
-------------------- All I ask is a wide screen and a projector to light her by...
Posts: 1373
From: Penistone Sheffield UK
Registered: Oct 2012
posted April 06, 2013 05:54 PM
Could be a slight warp on the reel do you get any noise from the film coming off the reel? It could catch when rewinding till the film pushes the sides of the reel out a little.
Take extra care it will cause scratches on your film.
If you try it the other way round use the problem reel as take up see if it still causes a problem.
-------------------- I love the smell of film in the morning.
posted April 06, 2013 07:35 PM
Hi David, The metal reel is not warped or catching or rubbing on the film so I'm going to just rewind them by hand using my hand cranks! As a last ditch effort I will try and use a metal take up-reel and see if that makes any difference?
It's still a mystery to me why this is happening? Thanks for all your suggestions. RS
posted April 08, 2013 07:41 AM
My first guess would be warpage of the reel, it can be very slight and hard to detect if subtle, 2nd geuss would be that the projector hasn't got enough torque to spin the metal reel at the correct speed with the heavier reel.
Posts: 1373
From: Penistone Sheffield UK
Registered: Oct 2012
posted April 08, 2013 03:28 PM
I believe the Elmo's projectors, the reels needed a larger diameter hub than some other makes. Is the problem reel small hub?
-------------------- I love the smell of film in the morning.