|
|
This topic comprises 2 pages: 1 2
|
|
Author
|
Topic: Please guys .... I really need help with this ....
|
|
|
|
|
John Wilson
Film God
Posts: 5438
From: Sydney, Australia.
Registered: Dec 1999
|
posted 01-07-2002 08:01 PM
Hi MattHave you checked the tightness of the drive belts? Are they worn?
Is the slower speed something new or has it always done this. If it's always been that way then the drive pulley may be too small. There are machines with variable speed modifications now. Contact me offsite if you wish. My email's up top of this post.
| IP: Logged
|
|
|
|
|
|
|
|
Steve Guttag
We forgot the crackers Gromit!!!
Posts: 12814
From: Annapolis, MD
Registered: Dec 1999
|
posted 01-07-2002 08:49 PM
You have a Century DAW...Standard Drive, double shutter with water cooling.First off, how do you know you are running slow? Have you measured the speed? If so, this would help to determine just where the problem lies. Do you have a poly-V belt system? If so is the belt properly seated? I've seen all too many poly-Vs that were not properly seated and caused a speed variation. Next, do you have the proper pulley set for the line frequency and generation of equipment? That is, do you have an async motor or sync motor and could you possibly have sync pulleys running with an async motor? This would cause the projector to run slow. Is the motor wired correctly, some motors can be wired for 120 or 230VAC...I have seen motors come straight from the factory wired for 230 for a 120volt market...As such sometimes the motors couldn't even overcome the static friction to start the projector all of the time. Download the manual for the Century projector/soundheads, Strong has a list of the various pulleys. For you to have changed the motor and still have the same problem starts to point to the pulley set and or belt position. Steve ------------------
"Old projectionists never die, they just changeover!"
| IP: Logged
|
|
Paul G. Thompson
The Weenie Man
Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000
|
posted 01-07-2002 08:57 PM
I would suspect there could be a problem with the drive or gear train. If you are using a Poly-V belt, it could be slipping without making any noise. I would recommend you roll the machine forward by hand, to make sure there is no binding or belt slippage. A Century should roll through by hand with a light finger touch on the flywheel. If you really have to "get on it" to roll it through, then read below: I have noted on many ocassions the bushings in the Century R-* soundheads have a tendency to freeze up (due to a lack of a drop of oil now and then), and that'll really bog things down! If you are using a notch timing belt, listen for it to jump cogs. Of course, after things warm up, it might seem ok. And naturally, the exact opposite could happen. The typical Repulsion-Induction motor speed is determined by the line frequency and the number of poles the motor has. So, I don't think it is a motor issue at all. One other thing......Is there a ballast dog bone in series with the motor that is shunted by a relay after starting? Are you using a 3 phase or a single phase motor? If you are using a capacitor start-capacitor run motor and the capacitors are located somewhere other than physically on the motor, you could change motors until you are blue in the face with no results. One of the capacitors (mostly the run capacitor) could be on the Fritz.
| IP: Logged
|
|
Tom Fermanian
Expert Film Handler
Posts: 101
From: Sainte Adele, Quebec, Canada
Registered: Dec 2001
|
posted 01-07-2002 08:58 PM
Hi,
Had a similar problem years ago, One of the Main fuses in the electrical Entrance had a problem, some spots in the building, we where mesuring the right current, some other area the curent was much lower, it was funny to see light bulbs dimmed whilst in the next room or section we had full brightness. Maybe,I said maybe, your section is not getting the right current, on the same circuit, are there any other electrical equipement,lights, maybe not running right ? If so maybe thats it, mesure your currents.------------------
| IP: Logged
|
|
|
|
Matt Close
Expert Film Handler
Posts: 226
From: Hervey Bay, QLD, Australia
Registered: Sep 2001
|
posted 01-07-2002 09:42 PM
Thanks everyone .... I think I will pursue a mechanical fault now, rather than a motor one. But, if anyone still wants to know, it is a single phase motor, capacitor inside, running 240volts/50Hz, 1450RPM.Does anybody know exactly which manual to download for a Century
'DAW 2'? .... And if so, where from? The reduction in speed is only minor ( I have compared it to other projectors, have only timed a trailer, will time a feature next) ..... a patron probably wouldn't notice it, but we all know how familiar you become with trailers or sections of a film, so I am sure I am not wrong about the speed problem... and the sessions are running over-time by several minutes  I have already spun the drive wheel by hand yesterday and today, and it spins quite freely with only a finger's touch... I can't feel any substantial resistance......
| 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