|
|
This topic comprises 2 pages: 1 2
|
|
Author
|
Topic: Vertical shaking in Ballantyne Pro 35
|
|
|
Paul G. Thompson
The Weenie Man
Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000
|
posted 10-05-2002 02:55 PM
Put your finger on the outboard bearing arm of the intermittant sprocket and see if it is "throbbing". If you feel any hammering or clunking whatsoever, that assembly has to be rebuilt. Check your gate tension and accentric screw to make sure it is adjusted properly. Make sure the outboard bearing thrust screw is set properly.If none of the above seem to cure the problem, more than likely you have a bad movement. I know of nothing else that will cause the problem. Some people have installed "Disney" couplers, and it has helped substantially. A friend of mine who is running PRO-35's told me recently that when a rebuild movement was instaled, the picture was as steady as a rock. Hope this helps.
| IP: Logged
|
|
|
|
|
|
|
|
Pat Moore
Master Film Handler
Posts: 363
Registered: Mar 2000
|
posted 10-05-2002 04:31 PM
Most of the bases are covered, it seems. Paul is absolutely correct -- if it is an older PRO35, the Star and Sprocket shafts that meet in the coupler could have been beating each other up, leaving sharp edges on the ends of the shafts that rip the coupler up when you put it on and every time you frame it afterwards. Most have been designed so that only the centers of the shafts meet and not the machined splines that match up with the coupler.When you check that outboard bearing assembly, have people been after it with a pliers to try and tighten it up? That knurled screw on the outside should just be snug -- it's purpose is to keep those two shafts together and not allow any lateral play. If it's over-tightened it wears the bearing out in the intermittent. If it's too loose you'll get the picture jump you mention and the projector will probably be noisy. Is that outboard bearing assembly silver or black? The black one one is the newer design and much, much preferred. Pat
| IP: Logged
|
|
|
|
Kenneth Wuepper
Phenomenal Film Handler
Posts: 1026
From: Saginaw, MI, USA
Registered: Feb 2002
|
posted 10-05-2002 08:30 PM
Hello, Darren,I saw a Century projector which had been changed from a 3 blade to a 2 blade shutter and the manager/operator sent back 2 prints of "On Golden Pond" because they were jumping on the screen. The real problem was shutter timing was so far off that you could see the image moving on the screen. Yes, there was a lot of travel ghost in the credits but he didn't notice that at all. Is the shutter timing off? KEN
| IP: Logged
|
|
|
|
Pat Moore
Master Film Handler
Posts: 363
Registered: Mar 2000
|
posted 10-06-2002 08:45 AM
Good catch, Shaun. Sometimes the obvious things are missed. Generally the PRO35, like any other projector, should run with very light tension from the film Gate. An eccentric screw allows this pressure to be easily adjusted while running. Tighten it just enough to steady the picture, and that should be the point where film noise gets quiet.One note -- light pressure in the Trap area generally causes a random "jitter" of the picture. If the movement is very rhythmic and regular, it's projector/mechanical or the film print itself. Seldom would you see such movement from a print on all reels and it sounds like this has shown up on all films, right? So we're probably back to the projector. If the theatre has the money, that new outboard arm assembly for the PRO35 (sorry, can't remember the part number offhand) and a coupler will fix the problem. If you're good mechanically, then the coupler can probably be rebuilt without buying that whole assembly. But heck, you'll need to be pretty good mechanically to change that outboard arm, too... Let me know how we can help. Pat
| IP: Logged
|
|
|
|
|
|
|
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 2 pages: 1 2
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
Home
Printer-friendly view of this topic