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Silicone spray is better than oil for lubricating roller shafts. It doesn't attract dirt and result in a grimy buildup over time that will eventually make the roller seize up again, like oil does. Clean the shaft and the inside of the roller with 99.9% alcohol. Spray the lube on a cloth, wipe it on the shaft, wipe off any excess so that only a thin film is left. Reassemble.
If you do use oil, a very light synthetic would be better than petroleum-based oil for plastic rollers.
Other than taking em off and wiping down, is there a recommended method for cleaning/lubricating the pad roller shafts/rollers? Noticed our mag head ones are a touch more resistant to spinning.
ISO to clean and a tiny bit of century oil on shaft? Or a thinner oil? Or is any oil there just going to creep and get all over film.
Yeah my personal one is a pretty vintage piece of kit, wall powered, but it has several ranges and a very precise long needled rate dial on it. Who knows if it is still calibrated, but not needed for some tasks.
Age doesn't matter as long as it flashes, nor does it being clalibrated matter unless you need to accuratelymeasure linear speed or RPM. You will mainly use it to slow down gear pairs, belting, and observe film travel to make sure everything is operating smoothly.
Yes!! A variable speed strobe can be very handy. You can use it on the gear side, the film side, and observe belt issues to find little quirks that you may not see with the naked eye. I had one that was more like a timing light for a car, but had variable speed.
Yeah my personal one is a pretty vintage piece of kit, wall powered, but it has several ranges and a very precise long needled rate dial on it. Who knows if it is still calibrated, but not needed for some tasks.
Just chiming in to say the noise was not detectable on our last screening after the oil change. But that print was also in great shape.
Not seeing any bounce on the shutter shaft, but will still check for flywheel end play in the next few days.
I do have a lab strobe handy, someone mention that is helpful to spot movement. What would be the technique?
Yes!! A variable speed strobe can be very handy. You can use it on the gear side, the film side, and observe belt issues to find little quirks that you may not see with the naked eye. I had one that was more like a timing light for a car, but had variable speed.
I had seen it several times on the JJ's and SA's in one particular chain in my service days, it multiple locations. Knowing that chain it is possible they used bad oil, never had it changed, or both. It was a constant at most all of their locations I and the other tech serviced. Also on teardown most if not all had destroyed inner and outer bushings, so the color was coming from the bushings for sure. Only a small percentage of them actually leaked though, which I found odd. Never had that issue with Simplex XL's for sure.
There was a large run of Century Wolk made fiber gears back in the 1980's that were not manufactured properly, that caused the knocking problem. After he moved from State St to his new location on Jefferson by Manny's deli, he bought a couple new gear hobbing machines and solved that problem. Otherwise best to buy LaVezxi gears as they actually worked.
Thanks John and all. I’m on a glorious vacation to cooler climes (Seattle) till August, but will examine the shaft(s) play situation in our run up to the next feature print.
no adjustments have been made leading up to the start of the noise, so hopefully not a prior adjustment that has worn flat spots etc.
i have heard that tick many times both 35 and 70...it sounds to me that you need to check for end play in the flywheel shaft on the movement if it moves in and out the preload adjustment on the intermittent needs to be adjusted to rid of excessive end play it also may be that someone adjusted too tight and the ball that presses against the cam has worn a flat spot needless to say it should be checked by a competent intermittent rebuilder like Mark, or Myself, or Tony or others familiar with how the century movement works, also like Mark said the shutter shaft on a single shutter are notorious for end play and knocking against the front support bearing BG9 or the shock spring has relaxed, carefully look at it while running and see if the shutter shaft is bouncing back and forth, the same condition can happen on the vertical shaft if bouncing up and down the tension collar at the very top needs to be adjusted, it does not take much play even .01 inch will telegraph through the gear train and cause that noise!
Correct on all of your statements. If the "worst case scenario" arose, it was either a full rebuild or replacement. If you flush with anything other than oil without taking the movement fully apart, you WILL have solvent residue that will contaminate the oil. In worst case scenario you'd be beyond the scope of flushing with oil anyways. That said, diesel does make a great solvent for cleaning the parts during a teardown or rebuild, but you'd still have to use a suitable cleaner to remove all residue of the diesel before reassembly.
As for pad roller oiling, I always cleaned the shafts and roller bore with alcohol, then used my finger to wipe a thin film of oil on the shaft. Install roller, turn it several times, and repeat with another thin film of oil. Never had a ny issues with oil getting on the film. NEVER just apply even a single drop of oil with the roller installed! That will just run all over onto the flanges and it won't penetrate the full length of the shaft anyways. I have used Century oil on our JJ with the method I described and it worked well. (But lighter oil like Simplex oil works a bit better.)
That all makes sense. I thought of the residue aspect after I posted. Hard to evaporate stuff from a relatively closed container.
Good answer on the rollers, because that is exactly what I did today (remove, clean, then a swipe of oil), I just thought I’d better ask before I do the rest too. Mag rollers are happy again.
Will repeat on the rest soon, but they spin freely right now.
Tony, I never had anything like that happen to a Century, but I have seen other strange stuff happen that is no fault of the projector. If you had rust in an intermittent, you obviously had contaminated oil that got put in the intermittent. I used to service a theater in Chicago where a disgruntled projectionist put battery acid on the gear train. That also caused a big orange, rusty mess, and everything had to be replaced on the gear side. Even the intermittent drive gear and cam had to be replaced. I installed a loaner SA and did the rebuild in my shop.
I had seen it several times on the JJ's and SA's in one particular chain in my service days, it multiple locations. Knowing that chain it is possible they used bad oil, never had it changed, or both. It was a constant at most all of their locations I and the other tech serviced. Also on teardown most if not all had destroyed inner and outer bushings, so the color was coming from the bushings for sure. Only a small percentage of them actually leaked though, which I found odd. Never had that issue with Simplex XL's for sure.
Tony, just wanted to ask here. I've read plenty of places about flushing them with diesel. But are you saying that if there was no evidence of non-oil or other problems in them, that it's best to just flush/refill with new oil instead and skip the solvents?
I can understand this from a mechanical perspective. Cause good oil creates that protective film, and a solvent flush would be starting over. Only for worst case scenarios?
Correct on all of your statements. If the "worst case scenario" arose, it was either a full rebuild or replacement. If you flush with anything other than oil without taking the movement fully apart, you WILL have solvent residue that will contaminate the oil. In worst case scenario you'd be beyond the scope of flushing with oil anyways. That said, diesel does make a great solvent for cleaning the parts during a teardown or rebuild, but you'd still have to use a suitable cleaner to remove all residue of the diesel before reassembly.
As for pad roller oiling, I always cleaned the shafts and roller bore with alcohol, then used my finger to wipe a thin film of oil on the shaft. Install roller, turn it several times, and repeat with another thin film of oil. Never had a ny issues with oil getting on the film. NEVER just apply even a single drop of oil with the roller installed! That will just run all over onto the flanges and it won't penetrate the full length of the shaft anyways. I have used Century oil on our JJ with the method I described and it worked well. (But lighter oil like Simplex oil works a bit better.)
Yes that is absolutely fine to do. In fact that's how I always do it.
Thanks for the clarification. Yeah in my head I wasn't thinking about the shaft still being there... but now it makes sense, just remove the roller so the risky flanges aren't there. I located the tools just now for each projector (of course the grub screws are different), and in the process learned that one of the 35/70 flippers was never tightened last time anyone did it. Checked em all! I didn't try it but it almost seems like two 70mm rollers would risk contacting each other at the flanges.
Not worried about the added 2min step when it's the right thing to do, now that we are not having to remove reel arms it's actually a pretty quick/tidy conversion at the projector as far as physical parts swappage goes.
Other than taking em off and wiping down, is there a recommended method for cleaning/lubricating the pad roller shafts/rollers? Noticed our mag head ones are a touch more resistant to spinning.
ISO to clean and a tiny bit of century oil on shaft? Or a thinner oil? Or is any oil there just going to creep and get all over film.
For clarity on the 70 conversion. It is possible to remove the upper 35mm pad roller without putting a 70mm one in it’s place?
Yes that is absolutely fine to do. In fact that's how I always do it.
On the systems that were cannibalized together for Hateful 8 they put two 70mm pad rollers so no matter which way you twisted that upper pad roller arm, you had a 70mm pad roller in position. That sounds like a great idea, but I actually do not prefer it as I've come across too many shafts that are slightly bent such that you can get one of them perfectly aligned for even clearance on both edges of the film, but when you twist it to the other position you can end up with a scenario where one side's clearance is fine and the other side is digging into the film or not holding the film onto the sprocket teeth at all...but that slightly bent shaft is often within spec for running a 35mm pad roller on.
For that reason, I prefer to run 70mm with just the one 70mm pad roller in place and the 35mm pad roller lives in the mag penthouse during 70mm projection. It will be obnoxiously obvious the moment you flip the pad roller if you engaged the shaft without a pad roller, so I don't see how anyone could possibly make the mistake.
I also keep a specific allen wrench needed for removing the "35/70" cap in the mag penthouse at all tims as well so it's always handy. It takes less than 30 seconds to pull the 35mm pad roller off for a 70mm show and the same for re-installing when switching back to 35mm. There is really no excuse for any JJ theater to ever run with the 35mm pad roller in place with it being so simple to prevent the dreaded "JJ scratches".
(Similarly I keep the Kelmar arm allen wrench needed on each electrical wireway along with the "not in use" size shaft at all times. It's no fun to be searching for tools when it comes time to make a switch.)
Never flush an intermittent with anything other than clean oil!!
Tony, just wanted to ask here. I've read plenty of places about flushing them with diesel. But are you saying that if there was no evidence of non-oil or other problems in them, that it's best to just flush/refill with new oil instead and skip the solvents?
I can understand this from a mechanical perspective. Cause good oil creates that protective film, and a solvent flush would be starting over. Only for worst case scenarios?
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