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Author Topic: Christie Projector Damping Fluid Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 05-06-2007 08:45 PM                     I can't find anywhere in the manual as to how much fluid to put into the dashpot. There is no line or any mark inside the cup. I'm assuming that you fill it up about 3/4 to leave room for the plunger. Sound good?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-06-2007 09:19 PM                     It's an airpot, not a dashpot. Just make sure there is enough air in the booth and you will be fine.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-06-2007 09:35 PM                     Also make darn sure the travel is not too much on the down stroke... or it will eventualy brake off the hollow shaft . Mark  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-06-2007 09:42 PM                     No fluid needed. If you're having a problem with the damper roller moving too freely or not freely enough, there is an adjustable valve on the bottom of the air pot accessable thru a hole on the bottom plate. It is adjusted with a small flat bladed screw driver. Also check to make sure the piston rod is not bent. I have seen these get bent causing them not to move freely if at all.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 05-06-2007 10:22 PM                     That's too funny. See what happens when you're used to century projectors. Thanks Brad. I'll make sure to open a window when I go there next...lol  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 05-07-2007 12:18 AM                    In that picture above it looks like the damping rollers are pulled to far apart. Shouldn't they be pulled apart just enough to have a slight bounce.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-07-2007 01:32 AM                     Pull out slack, then back off 2 sproket teeth or about 1/4" gap between the roller and sound drum. Thats what my manual has as the correct tension. Been doing it that way for almost 15 years with no problems.  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 05-07-2007 02:12 AM                    We use the 35GPS model here and we pull the film forward a sprocket or two until the damper rollers have a slight bounce in it. Doing this eliminates the risk of damaging the airpot and there is no problems with the sound. quote: Jeremy Weigel Also check to make sure the piston rod is not bent. I have seen these get bent causing them not to move freely if at all. Not had any problems in 15 years yet you have seen the piston rods become bent. Interesting...... Just looked at that manual here on film tech to see what the differance was between that model and the one we use. In that manual it states that you pull the film tight on the lower constant feed sprocket with out moving the idle rollers. Then you move the film forward on the sprocket two sprocket holes. That's the way it says to do it on ours and you do not have that big gap between the rollers and the drum.  |  IP: Logged Jim Bedford Jedi Master Film Handler Posts: 597 From: Telluride, CO, USA (733 mi. WNW of Rockwall, TX but it seems much, much longer) Registered: Jun 99 posted 05-07-2007 02:25 AM                        At least some of the early models of the Christie P35C were supplied with oil pots. I know because one of mine went bad (probably due to running low on oil and abrading the cylinder wall which reduced the hydraulic effect to almost nothing) causing warbles. Bevan Wright got me an airpot to replace it and now I'm running on one of each. Both seem to work equally well, but the airpot is certainly cleaner. And Darryl's right about the need to allow only the minimum bounce and tension as possible. In fact, the abrading of the cylinder walls in oil pots may be exacerbated by allowing too much bounce which will promote the rubbing of the piston on the cylinder wall.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-07-2007 03:07 AM                     quote: Darryl Spicer Not had any problems in 15 years yet you have seen the piston rods become bent. Interesting...... Back in our Regal days we had a sister theatre in OKC that was always having problems with the piston rod getting bent. It was usually due to someone getting a little too rough while cleaning the projector. Sometimes though it was due to someone getting curious and over adjusting the air valve so that the resistance was too great.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-07-2007 10:35 AM                     I don't think Christie's current projectors have this problem, but on the older ones I've serviced (late 90s) my trick was to simply snip a tiny amount off of the end of the rod before I installed the airpot. That way it wasn't physically long enough to "crash" when the lower arm pulled tight. Regarding tension. I pull only one perf of tension over zero tension. A Christie tech pointed that recommendation out to me years ago and I have achieved the best performance when threading in that fashion.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 05-07-2007 03:12 PM                     quote: Brad Miller ...my trick was to simply snip a tiny amount off of the end of the rod before I installed the airpot. That way it wasn't physically long enough to "crash" when the lower arm pulled tight. I don't know if Christie has changed the airpot that they supply, but I have always had to do that when replacing one, or else it would not fit properly. Seems like the airpot is generic and you have to cut the rod to the length desired for your application.  |  IP: Logged

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