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Author Topic: Simplex 35 Speed Issue Chad M Calpito Master Film Handler Posts: 435 From: San Diego, CA Registered: Apr 2006 posted 05-27-2008 10:41 AM                        Hi all. Well, last night while doing my booth shift, I got a report from my opening projectionist that he got a complaint of a sound problem with projector #9. I was told it was in reel #4 of Expelled. Now, I've had this print for at least a month without any sound problems on this print. So, during the next show, I do a series of troubleshooting by listening to the movie via the auditorium and the booth monitor speaker. I even look at the projector while running and I noticed that as the film goes down to the soundhead from the intermittent sprocket, it will bulge out for a few seconds, then return to normal and then bulge out again. I also checked the motor to see if it was hot and was normally and there weren't any strange noises or burning smell from the motor. I had my manager come up and look at it and he was confused by it as well. The motor, itself, is new. Anyway, the sound runs normally, then, it slows slightly and returns to normal. What could cause this problem? Could it be a belt inside the projector? Oh yeah, the projector also has a 5-Star Soundhead as well. Here is some information about the system: Simplex 35 (non-Turret) with the 5-Star Soundhead, Christie SLC Lamphouse w/ AM-10 Automation and a Christie AW3R Platter. I hope I described the problem good enough. Any ideas would be helpful. Much Thanks!  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 05-27-2008 12:30 PM                        It could be seizing bearings in the soundhead, it could be a worn or damaged gear on the soundhead or the bottom of the vertical shaft. It could be the sound drum bearing or the damping roller, It could be the coupling between the soundhead and the projector head. If you do not know how to check these things I would call in a qualified technician to check things out. If you a penthouse reader for digital sound on this screen you should be able to run in digital until you get things fixed. I will give you a warning though if you to choose to continue to run with the machine like this you could further damage the machine, or the film. A simple repair could turn into a more complicated and costly one.  |  IP: Logged Chad M Calpito Master Film Handler Posts: 435 From: San Diego, CA Registered: Apr 2006 posted 05-27-2008 01:52 PM                        Last night, after my manager saw it, he informed me he'll call our Technician to look at it. Luckily, last night was the last time we would be using the projector until the weekend. Anyway, I am hoping that it will get fixed ASAP since I'm unqualified to repair it at this level. I do agree that if continued running in it's current condition that things will get worse and more costly. Thanks for the information, Sean. Much appreciated.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-27-2008 03:14 PM                     If the 5 Star has a Bodine motor I'd suspect that before anything else! Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-27-2008 04:24 PM                     If it is the motor, you'd see it on screen as the flicker from the shutter would also be changing plus you would likely hear the motor changing pitch. Bad bearings on the sound drum would cause what you describe. If the motor is indeed speeding/slowing...then yes it could cause what you describe. If the motor is found to be the culprit...check the switch and/or relay that is controlling it as it may be failing and causing the motor to run erratically. Steve  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 05-27-2008 05:26 PM                     So, if you have a new motor, the obvious question to me is...why? What caused the old motor to fail? Has that been corrected? --jhawk  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 05-27-2008 06:44 PM                        I'm bettin' on the bearing, myself. (Cheap!) Louis  |  IP: Logged Chad M Calpito Master Film Handler Posts: 435 From: San Diego, CA Registered: Apr 2006 posted 05-27-2008 10:02 PM                        What I was told about the motor was changed out and that happened before I was fully transferred to the Gaslamp 15. In essence, I was told it was fairly new. Unfortunately, I didn't check to see if it was a Bodine motor last night. Currently, at this point, I won't rule anything out. I called the theatre this afternoon and my technician will be in tomorrow. As far as on-screen flicker, I didn't see any on the screen. So, the picture was good. In answer to your query, John, I don't know the exact details what caused the old motor to fail. I'm gonna have to try and dig up some maintenance records on #9 to see if I can see why it was replaced and such. Anyway, I hope to have an update for all of you soon.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-27-2008 10:06 PM                     On screen flicker might not be that noticable depending on how much it actually slows down and how bright the image is on the screen. It could also be a bearing starting to drag as Louis says... the rear rotary stabilizer bearings fail alot on those soundheads... The crap from the belts gets into the bearings. Edit: I'll rephrase this... All the bearings on 5 Stars fail alot. If you do install new ones try to use rubber sealed bearings on the drive shaft and idler but use only shielded bearings on the rotary stabilizer and lateral guide shafts. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-28-2008 08:18 AM                     Mark, the thing that would key ones key to the flicker is that the speed would be changing. If something is very even with a uniform period, you will adapt. However, once the period changes or is inconsistant, it becomes quite noticable. As to the bearings...I don't have that much problem with the bearings on the 5-star with the system that has been in use for the last 20-years. That is, the round-tooth belt system. Now with the square tooth system, yes, the idler pulley bearings (P-3368) were so horribly loaded they would often fail and the P-7015 bearing in the black bearing bracket is very poorly designed (no outside support of the shaft). We have generally sourced our bearings from good manufacturers and don't tend to have the problems with them. One problem we have had is from the rubbing alcohol users out there (for cleaning)...it will kill any bearing by wicking its way into the bearing, letching out the lubricant and then leaving its water behind to oxidize things. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-28-2008 08:51 AM                     Steve, A couple of fps slowdown may be difficult for the average Joe to perceive especially on a poorly lit screen but it will be very obvious in the sound. With bearings you will see the opposite in areas that have a very dry climate... Areas with higher humidity don't see as much bearing failure... I didn't see all that much faliure back in the Midwest due to dry climate. I blame it on the bearings that Wrong used. Cheap 2 buck bearings from Singapore that only had shields. Even Christie learned a long time ago that sealed bearings were necessary but Wrong continues to install shielded bearings in critical places that could take a dollar more expensive sealed bearing. The other problem with the 5 star is the alumnium pulleys. Round teeth or not in grind situations they wear in just a three or four years time and develop ridges around the outer diameter just like the P-35 alumnium pulleys do. The ridge then chews away at the belt and the resultant belt crud gets into the stabilizer bearings. Until I got almost all the 5 stars in this neck of the woods switched over to sealed bearings on the idler and drive shaft I used to see so many failures that I carried all the bearings, idler, and drive shaft in my sound service kit rather than have to run out to the van to get em. I agree that only good quality bearings should be installed!! The failures I see now are mainly rotary stabilizer bearings since they can't be sealed and thats just once in a while, occasionally still an idler because the bearings are undersized (and always have been) none the less they still do fail often enough that I still carry em in the van. Mark  |  IP: Logged Chad M Calpito Master Film Handler Posts: 435 From: San Diego, CA Registered: Apr 2006 posted 05-28-2008 09:58 AM                        The light image on screen from #9 is nicely lit. We are using a 3K Christie Xenon Bulb.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-28-2008 10:09 AM                     I have zero doubt that the climate difference has a great affect on how the mechanicals behave. I have a hard time convincing people that the use to tin plated connectors out here in the humid areas just fail (they go noisy first). As to Strong's aluminium plullies...I don't think I've had a single round tooth pully fail on the soundhead proper. Perhaps a motor pulley here and there...but probably more motor's (Bodine) than pulleys. I have not taken to sealed bearings as of yet as a rule but I don't doubt that they could help with keeping crud out...that is their job. Then again, I don't see that much curd around the bearings on the round tooth systems. We get good belt life too on the round tooth. Steve  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 05-28-2008 10:37 AM                        If it was the motor wouldn't both the projector head and the soundhead slow down and speed up at the same time? He says that the film is "bulging" out between the lower holdback sprocket and the sound drum which would lead me to beleive that the projector head is moving at a steady speed while the constant velocity sprocket in the soundhead is slowing down, or there is intermittent drag on the sound drum itself. Is that off base?  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 05-28-2008 10:45 AM                        If one has this issue and determines that bad bearings are the cause, how does one decide whether to replace the bearings in the roller or the ones in the drum shaft? I had a similiar issue (excessive flutter in soundtrack) with an SH-1000 and a technician correctly determined that the bad bearings were in the roller assembly. How did he know? In any case, this was an easy and not-very-expensive fix. As for the 5-star belts, do people replace these on a regular schedule, or just when they begin to show cracks? (The ones that I'm familiar with are in 1998-vintage 5-stars; I don't remember if these have square or round teeth.)  |  IP: Logged

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