This is topic Interchangeability of Cinecita, ORC and Century Parts in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Paul G. Thompson (Member # 655) on 09-09-2002, 01:30 AM:
Well, we had a problem in one of our theatres where an intermittant unit in one of our Cinecita projectors self-distructed due to oil starvation. I obtained a rebuilt Century movement from my supplier and when I installed the movement, I thought this was going to be a snap! So far, so good!WRONG!
However, other problems on the vertical shaft became apparent. The gear on the vertical shaft was undercut because of the heavy load of driving the old movement while the camshaft was seizing up.
Now, for the bucket of worms......
I had a junk ORC projector that had a perfectly good vertical shaft assembly in it. So, I snatched it and installed it in the machine I was working on. So far, so good. When I tried to install the shutter shaft, that's when I started having a bad day. I wanted to use the shutter shaft out of the ORC junker, but I could not even use it at all! I then decided to use the orginal shutter shaft from the machine I was working on, but I could not initially get the proper lash set-up. After about a half-hour of cursing, jiggling, yanking, shoving and pushing, I finally made it, but the lash was a little tighter than I would have liked to see it. I might add this: All the mating surfaces and the entire non-operating side were spotlessly clean.
As near as I can figure, there apparently is a machining error of a couple thousandths of an inch or so in the vertical shaft brackets of the Cinecita shaft and the ORC shaft. (I thought ORC's was a Cinecita.)
The reason why I am posting this is two-folded:
1. Was I trying to do the impossible by making one good machine out of two junkers, or:
2. Did I just run into a fluke of bad luck?
The machine is running, and it is so quiet that the projectionist almost panicked when he thought the machine did not start when he pushed the button. I was busy putting the other junker together, and I looked over my shoulder when he pushed the button because I actually thought the same thing. I finished putting the machine together - with about 30 seconds to spare before showtime.. 
I am asking these questions because maybe there is an easier way to make this work, and to let you all know that there could be a problem when you swap supposedly identical parts between two different machines.
Posted by Dick Prather (Member # 1136) on 09-09-2002, 02:35 AM:
Paul,
I have gotten in to the habit of replacing all Century gears in mated pairs. I have found so much different mesh from all the different makers of Century or clone gears it became a problem when rebuilding. I use gears from LaVezzi and find them to be the best. Also I started using a special anealed steel vertical shaft from them. It doesn't bend as easy and has a much better fit. Norm has it in stock. As far as shutter shafts not fitting sometimes you need a shim on the front bearing support to get the proper fit. Century's may be simple but they requirs special care to get everything into proper settings. All washers, spacers, etc. must be in the correct order and vertical shafe must have no play in it. Up & Down or in the GR-234 keyway. Otherwise one can get shutter shaft problems. Most times I try to mix Century gears I have to play around eith it.
Dick
Posted by Paul G. Thompson (Member # 655) on 09-09-2002, 12:40 PM:
Thanks, Dick. Sometimes it is difficult repairing junk junk with better junk with no parts to do it other than junk parts in the better junk to begin with.
Posted by Gordon McLeod (Member # 33) on 09-09-2002, 10:13 PM:
Cinecitta and Westrex had the option of a different gear pitch and as such are not always directly interchangeable
Posted by Manny Knowles (Member # 1171) on 09-09-2002, 10:50 PM:
Dick's comments raise another question: Which gears are supposed to have some "play" between them and which are supposed to have "no play" ?
Posted by Paul G. Thompson (Member # 655) on 09-10-2002, 01:14 AM:
Gordon, I didn't know it was that kind of a deal. I guess when someone buys off-the-wall equipment, they will pay an off-the-wall price for a part that is special order. Kind of reminds me of the lateral guide assembly on the Cinecita sound head. There is only one that will fit - and that has to be ordered from Bombay, India. When you finally get the part, odds are, it will not fit properly, not even in their soundheads. Century's won't fit, either.
Posted by Dick Prather (Member # 1136) on 09-10-2002, 03:38 AM:
Manny,
All the Century gears must have some play when meshed to it's mated gear. For me it's a feel from years of playing with them but it should be even around the gears. What I was refering to on the vertical shaft was no up / down movement when installed in the bearing retainers. The design of the intermittent gearing GR-7 to GR-234 will cause the vertical shaft to start bouncing up and down if there is any play, which moves the shutter shaft back and forth and so on.The bottom spring load of the shaft is two SG-14 spring washers with other stuff and the bottom bearing assembly. I started using an allen cap screw on the GR-4 and setting the spring tension so that the bearing cover above the lower bearing turns only with pressure. Hope the helps answer your question.
Dick
Posted by Gordon McLeod (Member # 33) on 09-10-2002, 08:10 PM:
Actually they are not off the wall projectors many of them are in daily use but they are not century's and not all created equal
In many ways the Westrex pitch was actually more durable and quieter
Posted by Paul G. Thompson (Member # 655) on 09-10-2002, 08:41 PM:
How about Cineceta's and ORC's? Those are ones nothing seems to fit, including some of the parts from the manufacturer. 