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Author Topic: Sprocket Problems on cat 700 reader. Tom Kroening Expert Film Handler Posts: 214 From: Janesville, WI USA Registered: Oct 1999 posted 08-17-2000 05:19 PM                     On one of the dolby readers we have makes a crunching noise. I'm thinking it could have a few hooked teeth on the sprocket. I've read that you can just take the sprocket off and turn it around. Is this recommended for the reader? Any suggestions would be helpful.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 08-17-2000 05:27 PM                     I haven't seen a penthouse reader ever get hooked teeth If it does you should be able to see it with a magnifier  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-17-2000 05:53 PM                     Tom, Check where the curley spring(actually an RCA soundhead spring)that locks the pad arms closed goes into the main casting. They sometimes oxidize in the hole. I don't know if its the dissimilar metals or if the alumnium casting just oxidizes. This happened allot to me back in the Chicago area, and with the salty air in your area it could also happen. After cleaning out the hole put a dot of super lube on the end of the spring to help keep it from oxidizing again. This could be the cause, especially if the pad arms are stiff to open or close. Also check for 2 film thicknesses of clearance between the pad roller and the sprocket. If the clearance is too small it can make noise when running film through. Finally, Is it possible that your film is damaged? Mark  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 08-18-2000 11:06 AM                     We had something similar. I notice it comes and goes with different film stocks. But it wasn't real loud or anything. One time, someone removed that first 35/70mm width roller the film goes around, but forgot to put back the little washer-spring thingy that pushes out the roller. I find the steel shaft for those rollers seem to loosen up after a while. Finally went around and "Lock-Tite"ed them.  |  IP: Logged Tom Kroening Expert Film Handler Posts: 214 From: Janesville, WI USA Registered: Oct 1999 posted 08-18-2000 02:15 PM                     This happens with all films yet doesnt affect the digital reading. I have noticed that after we moved a print from this projector to a different one, it seemed to start sheding its SDDS track (which could be unrelated but its a possibility that it is related). And also I havn't seen a hooked sprocket on a reader either, but the people that work at this theatre keep on threading the readers WAY too tight, like you could fit two fingers between the two tension rollers.  |  IP: Logged Tom Kroening Expert Film Handler Posts: 214 From: Janesville, WI USA Registered: Oct 1999 posted 08-18-2000 02:17 PM                     Also, with the springs. When i first got to this theatre I cleaned most of them off right away (you could hardly open any of the clips!). BTW if you hold the film between your fingers and put tension on it the noise stops.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 08-18-2000 03:52 PM                     Have you checked the physical alignment of the film entering and exiting the sprocket?  |  IP: Logged Tom Kroening Expert Film Handler Posts: 214 From: Janesville, WI USA Registered: Oct 1999 posted 08-18-2000 08:34 PM                     looks dead on to me, I will check it again though. It comes right out the bottom of a DTS head right into the reader.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 08-19-2000 01:44 AM                     I meant from the guide roller on the cat 700 into the sprocket as well as the first guide roller coming off of the sprocket. I'm not putting much of a bet that is your problem, but I did see that once before.  |  IP: Logged

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