This is topic Close encounters of the Christie kind in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Michael Barry (Member # 237) on 12-13-2000, 09:00 AM:
Post Removed.
Posted by Jeffry L. Johnson (Member # 453) on 12-13-2000, 11:07 AM:
Remember that your lower loop defines your picture/analog sound synchronization point in the auditorium. Placing the middle of the "Sound start" frame at the analog sound reader and the "Picture start" frame in the projector aperture will place picture/sound synch at about 50 feet away from the screen.You can adjust your lower loop size for different size auditoriums.
Posted by John Pytlak (Member # 331) on 12-13-2000, 11:37 AM:
Sound takes one frame (1/24 second) to travel about 50 feet. Standard SMPTE 40 specifies a 21 frame displacement between picture and analog sound on a release print. For a home screening room or drive-in where you sit only a few feet from the speaker(s), 21 frames would be the correct offset in threading. But if most of your audience is sitting 50 feet from the screen speakers, you want 20 frames between picture aperture and analog sound reader. In a very large theatre, a 19-frame offset would produce sync at 100 feet from the screen speakers.AFAIK, most digital sound systems use a "buffer", so the sync is adjustable within a range of offsets between the reader and projector aperture. The sound should be adjusted to be in sync for the center of the seating area in the theatre.
------------------
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 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Posted by Brad Miller (Member # 2) on 12-13-2000, 12:13 PM:
Be real careful about enlarging that lower loop on a Christie. If the Ultramittent is not outfitted with the guard rails, it will cause scratching of the film. If it is outfitted with the guard rails, the slapping will cause excess shedding. I cannot imagine anyone recommending a larger loop on this particular machine. In most auditoriums as has been mentioned above, this will also throw off the analog synchronization. Have the people at this theater actually noticed a reduction in shedding? I highly doubt it. You can cut down on print shedding far more on a Christie by merely making sure the shoe and pad rollers are properly aligned and not changing the gate bands until they fall apart (which should not happen unless someone has been messing around in there with a pair of pliers or something).My two cents: bad idea.
Posted by Randy Stankey (Member # 64) on 12-13-2000, 01:33 PM:
So, Michael; Now that you've seen your first "Purple Cow" what do you think?When I saw my first one I came away thinking, "It's just about all that people say it is.."
Shaky picture, shedding film, self-destructing dowsers... the works.
Thing is, I don't think it's a horrible design. It just seems that somewhere in the "implementation" of the thing that stuff got messed up. If it was made right in the first place I think it could actually be a good projector.
Still, if I was spending my OWN money, I wouldn't buy THAT cow.
Posted by Michael Barry (Member # 237) on 12-14-2000, 12:31 AM:
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Posted by Brad Miller (Member # 2) on 12-14-2000, 04:22 AM:
In the "manuals" section you can download the P35GP "parts price list" to get a rough estimate of what the parts cost as well as to get part numbers.
Posted by Mark Gulbrandsen (Member # 72) on 12-14-2000, 04:37 PM:
Just don't ask Christie to drop ship any parts for you. That jacks the price up about 20 points!
Mark
Posted by Paul G. Thompson (Member # 655) on 12-14-2000, 06:49 PM:
Just do what the manual recommends. That's why there are manuals! 
Posted by Michael Barry (Member # 237) on 12-14-2000, 07:29 PM:
Post Removed.
Posted by Paul G. Thompson (Member # 655) on 12-14-2000, 10:43 PM:
Certainly, by all means, take Brad's advice. I presumed that the manual would caution the operators on big lower (and upper) loops anyway. If the supposedly lower loop size recommended by the manual is actually to big, a correction should be made in the manual. In addition to Brad's advice, most operators would discover what Brad was talking about by simply rolling the machine through by hand and inspecting the loops as they change size, like most professional operators are supposed to do. At maximum size immediately after the pull-down, what stationary part can that loop come in contact with? Hopefully, it will not be able to come in contact with anything below the bottom of the intermittant sprocket. With minimum loop size at the start of the pull-down, does the loop look like it
is "straining" and pulling the shoe away from the intermittant sprocket? Another concern is what happens if there is a mis-frame? Will the loop size compensate for it when the machine is re-framed? Also, I wish I had a nickle for every time I yelled at my operators for not returning the framing knob back to its center position after the show when a mis-frame happened for one reason or the other. Especially an out- of-frame splice that they are too lazy to repair. I have walked in many booths when I was servicing as a field engineer, and 9 times out of ten, I would find the framing knob jammed up against the stop. I have seen lot of damaged film because operators won't look any further than the end of their nose!! 
Posted by Brad Miller (Member # 2) on 12-15-2000, 04:19 AM:
My favorite feature of the Christie projector is the incredibly easy task of simply locking the framing control down. Never again will there be visible negative splices on scope films or slightly out of center flat films. If the projectionists cannot thread in frame in the first place, what are they doing in the booth?All it takes is an allen wrench!
Posted by Mark Gulbrandsen (Member # 72) on 12-15-2000, 08:36 AM:
Has anyone ever tried covering the curved runner with velvet on a P-35? I would think this would eliminate most shedding altogether.
Mark
Posted by Brad Miller (Member # 2) on 12-15-2000, 08:41 AM:
Yes, I tried it about 18 months ago to see if it would steady the picture and found no discernable difference. In terms of shedding, that's not a problem if FilmGuard is used. I did find that replacing the velvet properly was a real pain and it was required two to three times a week, something that is far to frequent for a final result that made no difference in registration.
Posted by Paul Konen (Member # 41) on 12-15-2000, 09:17 AM:
I don't see why you should be rebuilding a projector every month. I have 24 to take care of and just replace parts that start to go out. Now this has been mainly confined to shutter assy (6), jack shaft(3) and two continuous roller assy and that's about it out of about 18 months of use. Just make sure that those belts aren't so tight to cause undue stress on the shutter assy or jack shaft.
Paul.
Posted by Paul G. Thompson (Member # 655) on 12-15-2000, 12:26 PM:
Brad, I have been asking that question for years. Still no answer. The theater owners get what they pay for when it comes to hiring booth personnel. However, I have fired a few.... 