Film-Tech Forum ARCHIVE: Belts

This is topic Belts in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Joe Redifer (Member # 3) on 09-20-1999, 09:37 PM:

Just a quickie here;

I am finding that the belts (especially the shutter belt) in my Christie projectors last about 10 months or so before they start to wear down and break. Is everybody else getting similar results, or did I just figure out how to make them last 3 times longer than usual?

Posted by RICK HAMILTON (Member # 115) on 09-20-1999, 10:19 PM:

Hey Joe,
I had a shitload of shutter belts wear out about 6 months ago. They didn't break though. It looked one of the pulleys stopped and the other pulley (jack shaft) kept spinning and just ate away about 4 or 5 teeth of the belt. We never had a belt actually break though. I went through a few multi-plexes and changed all of the shutter belts and pulleys(new and improved). All of the shutter pulleys had excessive wear. All of these theatres have the single blade shutter. It's kinda interesting because one of our theatres (8-plex) that is about 2 years old has double bladed shutters and not one pulley is showing any wear. I think its that sharp twist combined with the speed on that tiny belt that is causing all of our grief!

Posted by Joe Redifer (Member # 3) on 09-20-1999, 10:43 PM:

Speaking of the shutter belt pulleys, how do you get them off? I know they are loc-tited on, but I tried to heat them for about a minute with a lighter and the allen screws still wouldn't turn. Broke my wrench, in fact. Do I need a bigger heat source? Maybe I should just light the whole projector on fire?

Posted by Brad Miller (Member # 2) on 09-21-1999, 12:01 AM:

WD-40 and a lighter will do the trick nicely!

Actually, that's how the first operator of the AMC Sundance in Fort Worth used to clean the machines...just BURN the dirt off. (AMC fired him after one week.)

Actually, in reference to your belt lifespan question, I typically get about a year on them before the teeth start to wear off in spots and are unusable.

Where's Sean and Bevan? I know they read the forum! Give us some tips, please.

Posted by RICK HAMILTON (Member # 115) on 09-21-1999, 12:16 AM:

get a butane torch and give it about a one inch flame. hold the shutter assembly with the tip of the flame pointed directly into the set screw (where you would put the allen wrench) for about 30 secs. then insert the allen wrench like you were trying to loosen the screw and apply pressure. usually the pulley just slides right off!! just dont leave the torch lit and sit it on the platter aiming straight up. unfortunattly some stupid fire marshall decided that the ceiling tile above platters would be a good spot for sprinklers!! what do they know about booths??

Posted by Joe Redifer (Member # 3) on 09-21-1999, 01:04 AM:

The fire marshall expects all booths to be using FilmGuard, which basically eliminates water damage! Really. In fact, Brad says that you can take a FilmGuarded print, toss it into a swimming pool, leave it there for a week, drag it out and it will run perfectly. J/K.

But as far as water damage is concerned, FilmGuard really works wonders.

As far as the belts are concerned, doesn't even a year seem like an incredibly short lifespan? This is even when running the belts as loose as possible (but not so loose as to cause it to jump notches) and applying belt dressing, which really does help, by the way. And when you have 16 of these things like I do, it takes a loooooooong time to get them all changed out simply due to the cleaning of the inside of the machine that must occur at each belt change. Just the cleaning takes a good 45 minutes or longer. What are the advantages of belts, anyway? Christie's gear driven projectors were pretty good, from what I hear. And look at the Century projector!

Posted by Jim Ziegler (Member # 86) on 09-21-1999, 01:43 AM:

Only 16 belts, must be nice... As for your problems with pullys, I had just the opposite problem. Right after we opened (within 6 weeks) we had three houses where the allen screws loosened and the shutter would not stay in time.

Posted by Will Kutler (Member # 770) on 06-25-2001, 06:12 PM:

AHH-the Christie Projector! I would like to write another review about this machine! For safe keeping, change the Christie belts every three months! I have been told that there are some higher quality belts on the market than what Christie markets. Also, they now have heavier/beefed up pulleys instead of those cheap aluminum ones. You may be able to upgrade for free-contact Christie. Remove the gate and sheetmetal belt cover at least once a week and clean all of the crap out! Cover the projector up good when doing this to avoid getting this crap in the wrong places! Use a few drops of the Christie belt-lube every week after cleaning to help cut down on belt shedding - but do not overflood! Those gears are lock-tighted on and can be a pain in the WAHOO to get off! Looks like there were already some good suggestions posted. When replacing and adjusting the tension on the shutter/jackshaft belt, you just want it to touch in the middle. Too much tension on the belt can wear out the roller bearings in the jackshaft and shuttershaft assemblies! Belt driven systems can be very good if engineered properly, Christie's system is in need of definate reconsideration/reengineering! I experienced too many AWSHITS with the Christie Belt System-too many to count. At least with my trusty old Simplex E-7 (and Standard for that matter), shutter timing can easily be adjusted w/o having to stop the show! Also, be careful on being gentle with the manual pull-down knob, as rough handling can damage belts and cause them to skip over pulleys!
The photos included with the review of the Christie Projector in Film-Tech are an accurate representation of Christie belt wear!

Posted by Joe Redifer (Member # 3) on 06-25-2001, 07:12 PM:

I have heard from a good source that Christie has made many improvements to their projector. I haven't seen all of these in action yet, but so far it sounds fairly promising.

Posted by Paul Konen (Member # 41) on 06-26-2001, 09:33 AM:

Replace every 3 months? You must be a millionaire! Considering that list price on these 3 belts runs approx $60.00

We've replaced ours (24) once a year with good luck.

Paul.

Posted by Will Kutler (Member # 770) on 06-26-2001, 12:48 PM:

Sorry, I should have specified shutter/jackshaft belts on the Christie to be changed every 3 months. I wonder what you all are doing to have such good luck? We did get some to last about 6 months, but we did have to keep an eye on them! As far as cost?-that was out of my realm. I simply reported what supplies were needed to my bosses, and it was up to them (and the Home Office) to budget/order/pay for the stuff. My only concern was making sure our customers got the best - cost and politics be damned!

Posted by Brad Miller (Member # 2) on 06-26-2001, 02:51 PM:

The trick is to keep the pulleys clean, use the belt dressing and most importantly...keep the belts as loose as possible without them being able to jump notches in the pulleys. Running the belts snug will cause them to retire early.

Actually, a year's worth of running isn't that hard to get out of those belts if they are installed properly from the get go. I've had some that ran 2 years without a problem. Then again, I use start cues on the prints so the motors are never turned on to cue up the film when threading (for a 7 second automation douser open), so that's less wear on the belts.

Posted by Heyward Garner (Member # 722) on 06-30-2001, 12:56 AM:

Dude, I run Christies, and I do have the exact same problems. Their belts are horrible. I usually try to change them before they become a pain in my butt. The pulleys were a bitch! Once you've done a couple though, it's not too bad. Christie recently released a NEW pulley, yes NEW! Instead of aluminum, they offer steel now. I changed out four of ours back @ the end of Feb. and am fixing to do the rest here come the end of July, early Aug. My tech strongly suggested that changing the pulleys would increase belt life dramatically because the aluminum pulleys wear out and wear thin, thus creating a dilemma when expecting it to securely turn a floppy rubber thing that Christie sent to you. Anyways NO, you are not alone. =) Hope this is helpful.

Posted by Randy Stankey (Member # 64) on 06-30-2001, 02:27 AM:

I was just thinking about how to get those Lock-Tighted screws undone:

Lock-Tite is a cyanoacrylite (sp?) based adhesive, isn't it? That's the same stuff that super glue is made of, isn't it?

Super glue can be dissolved by acetone. If you ever checked the ingredients on that "super glue remover" that you can sometimes buy, it's made of acetone. In fact if you need a quick solution to remove spilled super glue you can use nail polish remover, which often contains acetone.

Therefore, it stands to reason that nail polish remover (or acetone if you can get it) would be a good solvent for Lock-Tite. Maybe somebody could try it. Next time I come upon that situation I'll give it a try and report back.

Posted by John Pytlak (Member # 331) on 06-30-2001, 07:37 AM:

FWIW, Christie's website has several technical bulletins on the shutter belts and pulleys:
http://www.christieinc.com/fldblt/FLDBLT_PULLEYS_105.pdf
http://www.christieinc.com/fldblt/FLDBLT_BeltDres_109.pdf

What are the details about getting the improved pulleys and belts?

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Will Kutler (Member # 770) on 06-30-2001, 11:59 AM:

Hi John!

I think that ours were free because of the warranty. The steel pulleys will still wear, but will outlast the aluminum. I have also been told that there are other manufacturers who market better belts than Christie. John, there is a company in N.Y. called W.M.(?) Berg who is a major gear/pulley manufacturer for small applications. Maybe you can pay them a technical visit and report back to us? They have a 1-800 number. I have their catalog at home (free), and it is not in front of me.

Posted by John Pytlak (Member # 331) on 06-30-2001, 12:40 PM:

Here is the website for W. M. Berg in East Rockaway, NY:
http://www.wmberg.com/overview.html

They seem to carry many components of interest to projectionists.

Posted by Michael Elam (Member # 788) on 07-02-2001, 08:10 PM:

How about a 'cheaper' source for the belts? Between the belts and
lateral guide rollers Bevan has no problem in getting his salary.