This is topic Please guys .... I really need help with this .... in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Matt Close (Member # 996) on 01-07-2002, 07:51 PM:
I have a Century DAW 2 35mm projector that is running slow..... What actually governs the speed in a projector?
Posted by Josh Jones (Member # 447) on 01-07-2002, 07:56 PM:
There is no speed governing device to my knowledge in a century, or any machine for that matter. the only device truely controlling the speed is the motor. do a little inspection. does the motor smell hot or particularly funky? if so it is probably on its way out. thats all I can think of. outside that you could have a line voltage droop that may cause a reduced operating speed. running motors undervoltoge will eventually destroy the rotor, as magnetic slip produces a lot of heat, eventually burning up the rotor, the windings, or both.Josh
Posted by John Wilson (Member # 269) on 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.
Posted by Matt Close (Member # 996) on 01-07-2002, 08:04 PM:
Thanks Josh .... I didn't think (but wasn't sure) that there was anything that could govern the speed of a projector other than the motor, which to my knowledge is governed by frequency, rather than voltage... yes? I have actually already tried another old motor and it runs at the same slow speed 
Of course, I could have two bad motors!! There doesn't seem to be any binding of gears or slipping of belts either ..... any other ideas? ... Anybody?
Posted by Matt Close (Member # 996) on 01-07-2002, 08:06 PM:
Thanks John ..... But , no ... this is a brand new problem...... At least I have never noticed it before ....... I've cleaned at re-tensioned the drive belt, but alas ... all is still not well
Posted by Richard Fowler (Member # 893) on 01-07-2002, 08:39 PM:
Is your model direct drive to the projection head or to the soundhead and then to the projector......I have seen rare instances on direct drive models where the gear on the main drive shaft was slipping on the drive shaft....I had one customer had this problem as the gear screws had become loose but bit enough to grab the shaft.....
Richard Fowler
TVP-Theatre and Video Products Inc. www.tvpmiami.com
Posted by Steve Guttag (Member # 268) on 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!"
Posted by Paul G. Thompson (Member # 655) on 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.
Posted by Tom Fermanian (Member # 1094) on 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.------------------
Posted by Tom Fermanian (Member # 1094) on 01-07-2002, 09:01 PM:
I forgot!,
Another situation, someone did an oil change in a projector, he added sound oil instead of projector oil Result: projector slowed up, almost binded! We found this out because the week-end man did the oil maintenance, the weekday guy was not told...------------------
Posted by Matt Close (Member # 996) on 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......
Posted by Paul G. Thompson (Member # 655) on 01-07-2002, 10:02 PM:
1450 RPM? I think your problem was from day one. I think you might have an incorrect pully ratio. get a strobe light and check what speed you are actually running at, and check your other machine (if you have one) and see what it is doing. Then take a long close look at your pulleys.
Posted by Steve Guttag (Member # 268) on 01-07-2002, 10:07 PM:
Download the first Century manual in the Soundhead section of the "manuals " page here on film-tech. I believe it is 1999 printing which lists various pulleys for the various configurations.Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Gordon McLeod (Member # 33) on 01-08-2002, 04:54 PM:
1450 is the correct RPM for a non syncronous motor in 50 Hz locations
Posted by Paul G. Thompson (Member # 655) on 01-08-2002, 06:38 PM:
oops.....
Posted by Brad Miller (Member # 2) on 01-08-2002, 06:45 PM:
Matt,Please remember not to use teaser subject headers.
GOOD "Need help with Century DAW2 projector running slow"
BAD "Please guys .... I really need help with this ...."
Also, this topic was already posted half an hour earlier by you under the more appropriate subject header ("Century DAW 2 Speed Problem"). I have since closed that thread.
Please read the FAQ in it's entirity before you post any further on these forums. Without these basic forms of organization to the forums, it makes things very confusing to people who are searching for an answer to this problem in the future.
Posted by Dave Macaulay (Member # 813) on 01-08-2002, 08:33 PM:
"Also, this topic was already posted half an hour earlier by you under the more appropriate subject header ("Century DAW 2 Speed Problem"). I have since closed that thread."Why close the one with a sensible topic?
Posted by Brad Miller (Member # 2) on 01-08-2002, 08:36 PM:
Because there were already more replies here. Also note that I cross plugged this thread so if someone is searching for this problem in the future they can find this discussion (because otherwise with the title of this thread it would get lost).
Posted by Matt Close (Member # 996) on 01-09-2002, 02:27 AM:
Sorry Brad ..... *stands himself in the corner and tells himself to face the wall*
(Honestly, I only put the 2nd topic up becase I hadn't sparked any interest with the first one ..... again, sorry guys)
Posted by John Eickhof (Member # 323) on 01-09-2002, 03:35 AM:
If the projector has been in use for a long time and is equipped with the poly-V belt, the motor pully has a tendancy to cahnge diameter! The V grooves will wear causing the diameter to reduce, thus slowing the machine down. I have had 60 cycle machines run as slow as 15% when the pully is worn! Especially if it is an original aluminum type sold by Century! Replace it with a steel pully! It will last longer!
Good luck!------------------
John Eickhof President, Chief Slave
Northwest Theatre Equipment Co., Inc.
P.O.Box 258
Wendell, ID. 83355-0258
208-536-5489
email: jeickhof@nteequip.com
Posted by Steve Guttag (Member # 268) on 01-09-2002, 10:04 AM:
Quick test for wear...Take the belt off...wipe your hand around the motor pulley...check your hand...if it is all cut up, then the pulley has worn a bit too long!
SG
------------------
"Old projectionists never die, they just changeover!"
Posted by Dave Macaulay (Member # 813) on 01-09-2002, 04:09 PM:
Steve, that seems a bit extreme 
Seriously, if it has poly-V belts that is the most likely problem. With a few years of use the pulleys get a mirror finish and unless the belt and pulleys are absolutely clean there is slippage. Every Century I've seen oozes oil and grease drippings down towards the belt and if you have a takeup drive the grease from that gear is hard to keep off the belt. I have seen this speed problem fairly often with well used Century setups. Sometimes the projector will even slow down as the reel plays - the takeup film roll is getting bigger, reel is going slower adding a bit more drag.
If you are about to replace the pulleys and belt, bite the bullet and get the toothed belt kit. No more slippage.
What drive do you have between soundhead and projector? I like the sound of the Hyvo chain best.
Posted by Gordon McLeod (Member # 33) on 01-09-2002, 04:25 PM:
Belt Dressing works wonders
Posted by John Wilson (Member # 269) on 01-11-2002, 02:00 AM:
Yeah...but don't do it in public. 
Posted by Don Sneed (Member # 955) on 01-11-2002, 10:22 AM:
Damn John, Now You Tell Me !!