Film-Tech Forum ARCHIVE: Loud Century Intermittent

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Posted by Manny Knowles (Member # 1171) on 07-15-2003, 04:11 PM:

One of my projectors has a noisy intermittent movement. It is louder compared with the others when they are all empty and this one gets even louder with film loaded and running.

I know that this unit was allowed to run dry so I'm thinking that's got to be a factor but the image on-screen is very steady so I don't think it's been totally trashed.

Is there any way to quiet this little fella down and nurse him back to health?

Posted by Sam Hunter (Member # 1119) on 07-15-2003, 06:06 PM:

Never touched one of those models but like all things mechanical if you run it dry you messed up. It will not get any better but I guess you can hope it doesn't get worse.
Maybe remove it and give it a good washing to maybe flush any fragments or gunk out will help.
Lots o Luck.

Posted by Manny Knowles (Member # 1171) on 07-15-2003, 06:10 PM:

I flushed it out with fresh oil until fragments stopped coming out and then filled it as normal.

Fragments. Oy!

Totally forgot about that. I guess this poor thing has been through the wringer.

Still...I'm interested in hearing ideas if anybody thinks there is something I should try.

Posted by John Westlund (Member # 913) on 07-15-2003, 06:18 PM:

Im no expert here but I would have to say that once the damage is done there is not much that can be done about it. Can you describe the noise at all? I assume that this is an SA. If you look in the SA manual under intermittent movement it has the procedure to adjust the end play of the cam shaft and to adjust the spacing between the cam and star. The adjustment of the spacing between the cam and star should only need to be done when the movement is rebuilt. I would NOT suggest that you do this if you are at all unclear of what to do because you could really destroy the movement if the adjustments are wrong. I have also been wondering about those procedures and exactly how the pros here on film-tech do them. Sorry I wasnt much help. I know that Mark rebuilds these things so im sure he will have much more information then I do.

P.S. One other thing that you could check is that the flywheel is secured in place. That can make the machine make a horrible noise as well.

Posted by Ken Layton (Member # 133) on 07-15-2003, 06:40 PM:

Try filing the intermittent with LaVezzi (synthetic) Intermittent Oil instead. Be sure to drain all the old oil out first.

Posted by Paul G. Thompson (Member # 655) on 07-15-2003, 06:46 PM:

Also check to see if the flywheel is securely attached.

Posted by Gordon McLeod (Member # 33) on 07-15-2003, 06:52 PM:

Skip the synthetic shit I have had so many diffent oils from Lavezzi I have lost count
What did the fragments look like? If it was jsut a thin trail of black powder I wouldn't sweat it.
There are 2 adjustment screws on the face of the movement
If you are daring and sure youare up to it
rack the framer to the bottom
thread up a loop of film
loosen the screws that hold the cover on the movement
there are 2 recessed screws at about the 2 oclock position tighten one in ans you are lossening the other the same amount it will either get louder and quieter. If you are going the wrong way reverse the direction then gently tighten down the case

Posted by John Westlund (Member # 913) on 07-15-2003, 06:52 PM:

I was just adding that to my post while you were posting I guess Paul [Wink]

Posted by Randy Stankey (Member # 64) on 07-15-2003, 10:26 PM:

With the Century intermittents that I worked on, oil changing was KEY to keeping them happy. I did it at LEAST twice per year. More if I could get away with it. (Managers don't like to buy projector oil for some weird reason.)

Unlike Simplex, et. al., they only have a few tablespoons full of oil in them. There is little room for error when monitoring the oil levels. With the others, as long as there's enough oil to squirt out the pipe at the top you're generally OK.

Another thing is that the design of a Simplex allows any metal shavings and gunk to collect at the bottom of the sump where it will do relatively little harm. (I often wonder about the efficacy of placing a "cow magnet" down in the sump.) In a Century, a little bit of gunk has potential to do a lot more damage.

When I change the oil in a Century I always drain the old oil, fill it up again, run the mechanism for a minute or two then drain and refill it again. It literally takes 5 squirts of a pump type oil can to fill one of those puppies. You won't waste that much oil. Besides, the amount of money spent on oil to flush out the gunk FAR outweighs the potential money spent if you have damage due to metal shavings inside the movement. (That's the argument I gave managers when they questioned me about my pracice of "wasting oil".)

Regarding noisy intermittents:
Notwithstanding the adjustment procedure that Gordon describes, some Centuries are noisier than others. I have seen some of them run so loudly you can hear the "clattering" noise down in the theater. The never missed a beat and they ran like that for weeks until the tech could get to the theater to fix them. (I wasn't a tech, myself, at that time.) Some of them have run for years, making a slight "clatter-clatter" sound as they go happily about their business. Other times, I have seen an appearently good intermittent which had never given a single sign of trouble melt down and die within a day.

IMHO, if the thing isn't so noisy that it bothers customers and it otherwise behaves normally I would keep an eye on it and let it run. (DO flush it out, though!) If you are the cautious type, you could order another intermittent so you have one on hand in the event the thing takes a shit on you. Replace it ad libitum. (Since it was run dry, it is more likely to fail.) If you are the adventurous type, you could study up and take a crack at realigning it. That would be up to you, though.

Posted by Paul G. Thompson (Member # 655) on 07-15-2003, 11:52 PM:

Manny, the contamination you found in the oil might have been cigar ashes if you got the oil from a now-defunct theatre supply dealer in Minnesota. [Big Grin]

Posted by Jack Ondracek (Member # 1466) on 07-16-2003, 01:05 AM:

Bad boy, Paul!

Posted by Paul G. Thompson (Member # 655) on 07-16-2003, 01:57 AM:

Jack, I got some that way.... [Big Grin]

Posted by Dick Prather (Member # 1136) on 07-16-2003, 03:53 AM:

Manny,
If the movement was run dry for any length of time chances are the cam pin has a couple of flat spots on it. It may not be able to be quiet. Gordon has the instructions to adjust it. I would add to check the end play on both star and cam first. There should be none or just perceptible. Do not loosen the 5 cover screws very much to allow any case movement. Make your adjustment then stop the machine and check for sprocket movement at the 4 rest points. Tighten the 5 screws and check for movement again.

Century intermittents can be a pain in the a-s. I do get better results adjusting them on the intermittent run-in stand while they are running.

Posted by System Notices (Member # 2357) on 06-11-2005, 02:27 PM:

It has been 696 days since the last post.

Posted by Dominic Espinosa (Member # 2122) on 06-11-2005, 02:27 PM:

Something I've been wondering about...
Is there anything recommended for flushing these besides oil?
Anything that one should run through them to completely remove all the gunk and junk, say in the event of changing the case seals?

As for sound, it always amazes me how much they quiet down at the 500 hour oil change I try to give them.

Posted by Mark Gulbrandsen (Member # 72) on 06-11-2005, 03:01 PM:

quote: Dominic Espinosa
Something I've been wondering about...
Is there anything recommended for flushing these besides oil?

We probably get three to four of these a week at CLACO. NO!... Don't flush a movement out. All you will do is loosen up more gunk and cause faster wear of the parts inside. Have the movement torn down, cleaned, and inspected to see whats really wrong.... it may only need a new cam pin or just a cam pin and star. BTW: Movements should really be dismantled, ultrasonically cleaned then then inspected.

I reccomend adding a tiny disk magnet inside a rebuilt movement to attract metal particles that will cause faster wear and switching to LAVezzi oil is also a great idea and will drastically extend a new or rebuilt movements life span. It may even quiet a noisy one down a bit but there is still wear in there that will need to be taken care of Sooner than Later.

Mark

Posted by Monte L Fullmer (Member # 2797) on 06-11-2005, 03:53 PM:

Yo Mark - any buzz on that "loaner" SA intermittent that you had planned on sending me for the Terrace?

I looked in the sight glass on this thing and the oil is definite need of changing-pretty dark. Yet, interestingly that the movement had quieted down for some reason-doesn't "clunk-clunk-clunk" anymore on startup. Any clues?

thx-Monte

Posted by Mark Gulbrandsen (Member # 72) on 06-11-2005, 05:52 PM:

Its hard to say Monte, possibly dried oil in the oil spirals, running it a while will sometimes dissolve that. Will send the loaner movement out Monday if you think you still need it, thought you were going to be on vacation so didn't send it last week. Anyway call and let me know Monday morning. BTW: Using LaVezzi synthetic is a good idea as oil will not evaporate on the spirals.... synthetic oil does not evaporate.

Mark

Posted by Randy Bowden (Member # 587) on 06-14-2005, 05:28 PM:

I do consider myself a bit of an expert of this subject(I've rebuilt well over a thousand intermittents)...So aside from the possibility that your flywheel came loose as mentioned previously. The ONLY way to quiet down that intermittent is to have it rebuilt, if it was run dry the cam pin does indeed have flat spots, the bushings are also likely worn down, that also adds to the noise factor. 9 times out of 10 I replace the bushings on a century rebuild and I don't bother with crappy mod that Strong made by adding oil seals to the intermittent. Talk about a stupid thing to do. Shortening the bushing to add an oil seal only shortens the life of the bushing, thus making the intermittent wear out faster. The long spiral non seal bushings that Lavezzi sells work the best, they last the longest and DO NOT LEAK! Sorry to get off track but it feels good to vent sometimes.

Posted by Mark Gulbrandsen (Member # 72) on 06-14-2005, 07:04 PM:

quote:
Shortening the bushing to add an oil seal only shortens the life of the bushing, thus making the intermittent wear out faster. The long spiral non seal bushings that Lavezzi sells work the best, they last the longest and DO NOT LEAK!

Er, ah Randy, Its actually desriable for a bushing to seep just a very teenie-tiny bit of oil. This is perfectly normal and is actually desriable. You can find info on this in any engineering type refrence book. Brand new Simplex movements always exhibit this as should any properly rebuilt movement. If it does not then the bushing was not lapped out correctly, clearance is too tight, and the shaft and bushing are not getting enough oil cushion along its full length. A bushings bore should ALWAYS be checked with a hole gauge to be sure that there is just enough clearance for the weight of oil being used. Lack of a tiny bit of seepage can lead to a seize up on a hot running machine or just plain premature wear. I somewhat agree with you on the bushing thing but if you do the calculations you'll find that the shorter bushings are only about 14.6% shy of the originals actual bearing surface.... not enough to matter much. I did these calculations years back when I built my VistaVision movements as I needed to use the seals to keep the oil inside the movement! The VV movement that has seen the most service still runs perfect almost 12 years later.

quote: Randy Bowden
I replace the bushings on a century rebuild and I don't bother with crappy mod that Strong made by adding oil seals to the intermittent.

Don't blame Strong for that, it was an ORC thing they inherited and works just fine and as designed over the life of the seals.

Todays pisser is the poor overall quality of intermittant parts that are made.... not even close to the quality of stuff made in years past, all because they need to be produced by CNC to turn a profit(maybe). Check them for your self some time with a Rockwell hardness tester... the older parts are generally pretty amazing quality compared to todays stuff, even todays cast iron is crap compared to stuff made years ago, thank the EPA for that change. You'll find the best made stars and cams are those that were made by Phillips back in the 50's and 60's, they just don't wear out if the oil is properly maintained. Sad that all the artists of yesteryear are all dead.

Mark @ CLACO

BTW: I'm well over 1000+ movements ahead of ya.....

Posted by Randy Bowden (Member # 587) on 06-14-2005, 07:22 PM:

WOW...now I remember why I don't post on here anymore...you know everything.

Posted by Marc Hansen (Member # 705) on 06-14-2005, 09:04 PM:

quote: Mark Gulbrandsen
A bushings bore should ALWAYS be checked with a hole gauge to be sure that there is just enough clearance for the weight of oil being used.

Mark - How much clearance would you run?

Posted by Mark Gulbrandsen (Member # 72) on 06-15-2005, 12:36 AM:

quote: Randy Bowden
WOW...now I remember why I don't post on here anymore...you know everything.

Hardly Randy, but I did at least do some research and talked to the folks that make the parts back when I built the VV movements as to the proper clearance rquired.

quote: Marc Hansen
Mark - How much clearance would you run?

Mark,

Now you're a machinist and you should know the basics..... The Bushings in the Vista movements have about .0005 oil clearance for 20 weight synthetic(LaVezzi Oil) to start with. This clearance was actually reccomended by none other than Al LaVezzi himself. I had arrived at just slightly less than that using formulas provided by friends that design machnery and also from Machinery's Handbook. After run in this of course increases again just slightly.

BTW: Yes, I do own a set of hole gauges just in the sizes I use in Movements and a full set of gauge blocks. No, I don't ALWAYS use the hole gauges in every day movement repair/rebuild...... they're too expensive. But its how I would teach someone to do it. I use the gauge blocks to double check calibration on my mics and calipers and for making other odd measurements. Also, through the use of the hole gauges it makes it alot easier for someone new to learn how to judge fit by how it feels. I've also been through LaVezzi's plant a number of times and have seen their people using hole gauges to check the specs of bores on new bushings. In the last trip they had switched to a more modern video tolerance checking system that was pretty cool.

Mark

Posted by Michael Schaffer (Member # 1204) on 06-15-2005, 03:38 AM:

quote: Mark Gulbrandsen
You'll find the best made stars and cams are those that were made by Phillips back in the 50's and 60's, they just don't wear out if the oil is properly maintained. Sad that all the artists of yesteryear are all dead.

Maybe not all of them. Kinoton intermittents are still built in-house by master craftsmen, and if you know what it takes to get a master craftsman's certification in Germany (where the equivalents of "bachelor" and "master" are not university degrees, but strictly controlled craftsman's titles) then it is easy to understand why there are so few problems with these intermittents. There may be the odd bad egg too, but generally, these intermittents give you very little trouble and a very steady picture for many, many years.

Posted by Mark Gulbrandsen (Member # 72) on 06-15-2005, 09:02 AM:

Michael,

I've never had to replace a Kinoton movement or a Phillips for that matter, just tear down, inspect, and clean up. I've only had to replace seals or couplings on FP-20 type movements. I've replaced a few old style fibre drunken cams in early portable Phillips 16's and FP-16's though. I was primarily referring to movement parts that I have actually measured the hardness on, mainly U.S. made parts and I happened to own a DP-70 at that time and the hardness of those parts surpassed everything else I had brought to measure, alot of it also has to do with the quality of the steel being used. So yes, it seems that all U.S. craftsman are long gone but its nice that Kinoton still have a few left.

Mark

Posted by Marc Hansen (Member # 705) on 06-15-2005, 10:00 AM:

Thanks Mark Thats the area I was thinking (3-5 tenths). I have honing equipment & bore gauges so it's easy to hit a tenth.

Posted by Mark Gulbrandsen (Member # 72) on 06-15-2005, 11:50 AM:

Yea, Thats actually what the factory recommends. You can't generally hit that by just the hone and feel method but with alot of practice one can get pretty close to that. I wanted to keep the VV movement bushings tight and to spec so as much oil would stay in the star wheel sprial as was possible with the movement in the vertical position. This way when it would sit overnight the oil won't completely drain back down from the bushings and cause accelerated wear to those parts ever day it was re-started. I wanted to just have to make these movements one time and forget about them except for occasional oil changes.

P.S. I wish I had a real honning machine.... [thumbsup]

, I just work with regular barrel laps [Eek!]

.

Mark