This is topic The Silence of the Projectors in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Manuel Francisco Valencia (Member # 710) on 05-21-2001, 05:21 AM:
Nifty subject title huh? But, being the operator of a P35GPS, silent projector is pretty much an oxymoron. I have heard that these are supposed to be the quietest projectors on the market. With the way some people talk about them you would imagine that they have a "stealth mode" button hidden somewhere. But this is not the case. On some of my projectors the noise is so loud that I can barely hear the monitor. I have read many posts of people speaking of them in the same way. I was just wondering if anyone has had any real success in silencing these projectors. I mean, what in the hell is making these things run so loud. TaTa
H
Posted by Randy Stankey (Member # 64) on 05-21-2001, 09:06 AM:
Here's my take on the subject:
- Keep them clean. I mean religiously clean! Clean them before every threading and clean them well every night. Do a good "take apart" cleaning once every week or so. Christie projectors don't like to be dirty. Problem is that they get dirty just standing still!
- Check the belts. Make sure they aren't too tight or too loose. They should be just tight enough so that the teeth grab the pulleys and don't slap around when they run. Too tight or too loose and they will spite you in all sorts of ways. If they are starting to shed black junk all over the insides of the projector change them.
- Use belt dressing. You can buy it from Christie or you can get it at the hardware store. Look for a brand called Panef. You won't believe how quiet this will make your projectors. It's like magic!
- Make sure you are threading correctly. Every Christie projector I work on came with a little poster that tells how to thread. I have them posted up in various places throught our booths. If the loops are too big or too small they will be noisy. (And probalby damage film.) If you thread the sound head with too much tension, not only will it be noisy you stand to damage the projector. (Unless you have those "snubbers" installed in your sound heads.) You should thread so that there's only one sprocket hole's worth of tension. Just enough so that the rollers "float" off the sound drum and no more.
- Does the intermittent clatter? It ought to be quiet. Christie intermittents (I mean ULTRAmittents) can go bad on you in a heartbeat. They'll either run forever or they won't run at all. They are sealed so there's nothing you can do but replace them once they go bad.
- Finally, make sure that all your sprockets and pad rollers are aligned properly. If they are off, even by a little bit, they will be noisy and can damage film. Check the trap/gate alignment while you're at it.
Once you get the hang of it, Christies aren't a bad projector but they aren't particularly good, either. There's a lot of maintanence involved in keeping this (supposedly) maintanence free projector running right!
Posted by Ari Nordström (Member # 288) on 05-30-2001, 02:38 PM:
Sometimes it doesn't help to keep them religiously clean (I like that expression 
). If you get an old & worn print, the loops often make a lot of noise no matter what you do.
Posted by Mark Gulbrandsen (Member # 72) on 05-30-2001, 05:30 PM:
They can be quieted with a 44 magnum which can be had from this hit man> 
! Just kidding...... 
If you install Sonex on the walls and 6" shag carpeting on the booth floor it will help allot. You may have a small dust problem but nothing that Filmguard won't cure.
Will it take 4 shots or 5 to silence it? Or was it 5 shots or 6?
Dirty Harry
Posted by Joe Redifer (Member # 3) on 05-30-2001, 06:30 PM:
Ditto to everything Randy said in his post above. Be aware that Christie's belt dressing is the exact same thing as Panef belt dressing, so don't be fightened or concerned that you're not getting the same thing. Belt dressing will also make the projector feel 10 to a billion times smoother as you advance the thing manually.Also, if your projector is skipping notches when you advance it, throw it away and get a new one (the entire projector). Actually there is probably a simpler method than that. I took me a while to correct this problem on one of my Christie's, but I can't exactly remember what I did... it was so long ago. But it never had that problem again. Perhaps Christie could re-educate us on the technique.
PG35-GPS' are designed to cause a bullet to richochet. I'm still limping
Posted by Jonathan Haglund (Member # 807) on 05-30-2001, 07:35 PM:
What is sonex?And Joe, if you remember what it was you did, could you post it here? I'm having the same problem right now on one of my christies and can't figure it out (not that I've put a whole lot of time into it though :/)
Posted by Randy Stankey (Member # 64) on 05-30-2001, 07:40 PM:
When you have old, crummy film it does make a different sound as it runs through the projector but that sound is completely different from the usual symphony of Christie bumps and grinds.You get a "Wzzzzhhh" sound as the belts grind off the pulleys.
You get a "Thunk-Thunk" sound as the teeth on the belts skip off the teeth in the pulleys.
You get a "Weeeee-Weeee" sound as the bearings start to go South on you.
You get a "ZZZZZZZZ" sound as the film ticks off the sprocket teeth when the tension of the sound head is too tight.
You get a "Nya-Nya-Nya" sound if the pad rollers are set wrong and the film starts to go wonky.
You get a "Ticka-Ticka-CHUNK" sound when the ultramittent is about to blow up on you.
The sound that old, crummy film makes is more like a "Kt-t-t-t-t-t" sound.
Put them all together and it goes something like this:
"Wzzzzhhh-Thunk-Thunk-Weeeee-ZZZZZZZ-Nya-Nya-Ticka-Ticka-CHUNK-Kt-t-t-t-t-t"
Posted by Brad Miller (Member # 2) on 05-30-2001, 08:33 PM:
Jonathan - The cure for that problem is to take the belts off and get a small flat bladed screwdriver and scrape out all of the belt shavings in between the pulley teeth. Using the belt dressing will greatly help cut down on the shavings, but if your pulleys are not CLEAN, the teeth in the inner timing belt can actually ride over the dirt and not fully grab the pulley. Generally the pulley that causes the most problem is #5 on the inner timing belt as can be seen in the manual download on page 26 of the "Christie P35GPS projector manual" in the manual section here.
Posted by Joe Redifer (Member # 3) on 05-30-2001, 09:50 PM:
ALWAYS make sure to completely clean each gear and pulley 100% each time you change the belts. Inbetween each and every notch.Perhaps that was the solution to that problem. Maybe I don't remember it since it was so simple and I did that on each projector every time I changed belts just out of habit.
Posted by William Hooper (Member # 71) on 05-31-2001, 12:44 AM:
quote:
What is sonex?
Sonex is a brand of acoustically-absorbent material designed to be hung on walls to deaden room noise. "Sonex" is often used generically to refer to any wall-mounted acoustical foam.
It can be seen covering the walls of some noisy industrial installations, most broadcasting & recording facilities, & for some unknown reason, Star Trek sets.
Sonex is an expensive brand; there are other manufacturers of acoustical foam. Check the Holy Grainger Catalog, or their website. Search for "acoustical foam", you'll get a number of hits like this one:
http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611783082
Modern acoustical foams are remarkable. They'll reduce noise in a room dramatically.
Hang it up. Discover that it gets warm as noise increases (where did you think the energy went, anyway?) Have fun installing it by cutting the odd-shaped pieces with an electric carving knife. Be the 12 billionth person to observe that there is male & female sonex.