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Author Topic: Three time's the curse for a Norelco AAII vertical shaft John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 06-05-2010 12:15 AM                     I have a theater with a AAII. About 8 months ago, got a call that it stopped running, turned out to be a stripped fiber shutter gear (the one on the vertical shaft.) Interestingly, it is only stripped about 180deg around. The customer has two gutted spare AAII's so I took the vertical shaft from one of them, installed it in the proj, and it seemed to be running fine. Until about 2 months ago .... Got a call that the projector wasn't running again. Same problem, stripped fiber shutter gear. This one is stripped 360degs around. Everything seemed to be OK, nothing that would stop the shutter in the shutter area, the gate seemed to not to be interfering or anything. I turn it by hand for a long time looking for problems. The oil pump is working good, the little tubes shooting oil right at the gears, intermittent, etc. So I took the other spare vertical shaft and put it in the projector- I notice this vertical shaft has a brass shutter gear instead a fiber, I figured there must have been an issue at one time and the solution was make to make them out of brass. Check it over again, and it seems OK ... until today. Projector stopped again. This time it turns out to be the shutter compensator (the big gear assembly that slides up and down on the vertical shaft, it's called a 'fork' in the book.) It's seized on the shaft; the fork won't spin or go up and down. Also, the fiber gear at the bottom of the shaft is stripped in one section only, indicating the motor spun while the shaft was frozen and just ate the gear in that position. All the oil in the projector reservoir is black colored. OK, so I'm stumped. I don't work on these enough to get really good. Does anyone one have any suggestions? Some thoughts I wonder but am not sure of: At this location, the operators 'goose' (turn it on/off/on/off)the projector to run down the film to get the '8 in the gate.' Also, I suspect the operators try to open the gate just when the indicator line lines up to the sprocket, while the projector has almost but not quite stopped.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-05-2010 12:23 AM                     Someone tried to open the trap when the machine was running or coasting to a stop  |  IP: Logged Randy Bowden Expert Film Handler Posts: 146 From: Portland, OR, USA Registered: Aug 2000 posted 06-05-2010 12:33 AM                     I'm thinking the same thing as Gordon. The AA is built like a tank and it's been a number of years since I've needed to work on one, so I'm having a hard time coming up with any other possible cuases.  |  IP: Logged Robert Minichino Master Film Handler Posts: 350 From: Haskell, NJ, USA Registered: Dec 2005 posted 06-05-2010 02:04 AM                        I'll join the chorus, they're opening the gate with the machine still running or coasting. Changing the shutter gear from fiber to brass just moved the damage to a different weak point in the machine. I've just torn mine down and rebuilt them, and the only way I can see that damage happening without opening the gate is if the shutter shaft seizes, and that would be obvious.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-05-2010 08:52 AM                        Yep, these things run FOREVER if not abused. Therefore, abuse is more than suspected. We changed to JJ Century when professionalism went out-the-window. Louis  |  IP: Logged Michael Hossen Expert Film Handler Posts: 136 From: Perth, Australia Registered: Apr 2007 posted 06-05-2010 09:21 AM                        Some people just don't deserve Norelcos!  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 06-05-2010 10:17 AM                        John, Why don't you install a micro switch that will kill the motor when the gate is opened? I have seen this done at a AAII house with less then professional operators. This will not solve the problem as the machine still needs to coast to a stop but it might help minimize the damage.  |  IP: Logged Robert Minichino Master Film Handler Posts: 350 From: Haskell, NJ, USA Registered: Dec 2005 posted 06-05-2010 12:00 PM                        I've considered adding a solenoid to the gate to prevent it from opening until a short delay after the motor stops, just to prevent "money shifts" like this from happening accidentally.  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 06-05-2010 12:21 PM                        That's a good idea. Maybe some kind of magnet to keep it closed would work as well.  |  IP: Logged Randy Bowden Expert Film Handler Posts: 146 From: Portland, OR, USA Registered: Aug 2000 posted 06-05-2010 12:38 PM                     Next time, bring a cattle prod with you. Maybe that will get the point across. I used to run the Norelco projectors a the Eastgate here in Portland (largest screen until it closed) I have such fond memories. No D-Cinema presentation could ever bring about that kind of nastalgia.  |  IP: Logged Robert Koch Film Handler Posts: 93 From: Williams Ca USA Registered: Apr 2006 posted 06-05-2010 02:17 PM                     Get rid of those "hamburgers" in the booth. They can`t be trusted with a wonderful mechanism such as this. The very fact that they inch down with the drive motor makes me cringe. Maybe Louis solution is the best; when you bring clowns like these into the booth "the show is truly over".  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 06-05-2010 02:18 PM                     Hi, all; I just wanted to throw this issue out there, in case there's some thing about it I'm completely missing. Just about everything on this machine is expensive, so I'm trying to not overlook anything. As I dismantle it, I admit I just love the fit and finish of the assemblies. The vertical shaft in a Century seems like a toy by comparison, but even back in the 1960's I bet these projectors were much more expensive than any other. Sean, there is a shutoff switch on the gate opening lever (and upper loop trip.) I have it set to a hair's-breath on opening. The projector does take about 5 full seconds to wind down though. Robert, that is an excellent idea, but is probably cost-prohibited. And of course, I have no control over the operators. Actually I'd like to find some other reason for this, if there is one. I'm wondering why it's happening three times in a short time.... I'll try to take some pictures. I guess there are a lot of techs that have never even seen a AAII, let alone work on one.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-05-2010 03:54 PM                        I think we've hit the nail on the head. People vs. excellent machine: not going to have a good outcome. Plenty of JJ's around, if you need 70. Louis  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-05-2010 07:47 PM                     I've see all of the things you mentioned happen. Some of the things that will kill the fibre shutter gears are: A sudden filum pile up that brings the projector to a sudden stop, repeated on and off power bumps, and motor issues. I have seen the bronze gear do exactly the same thing o don't bet your reputation on it! The last batch of DP-70 rebuilds I did all had SSD variable speed motors on them. We also did an auto rotate to gate open position after the projector ame to a stop. Was pretty slick. As to the seizing of the gear to the shaft... did you loosen the bearing retainer plate that secures the self aligning center bearing in it's holder when installing thesethree shafts? You absolutely have to do this due to slight machining variances in baring retainers. If you take the plat completely off you will find that the bore on the center bearing boss is considerably larger than the OD of the bearing. If you don't loosen the retainer plate when installing the shaft this can lead to an ever so slight bow in the shaft that will cause the gear to gaul to the shaft either where the gear passes through the shutter compensator bracket or through the gear. Also. an excess of crud on the top of the compensator or gear bore that would cut off the entrance of oil around where the shaft passes thorugh the bores. Akso, note that the verticle shaft hangs by the top bearing and is just radially supported by the other two bearings. It is virtually impossible to open the gate a properly assembled DP-70 while it is running without lots and lots of intended force. There is a centrifigual plate at the end of the shutter shaft that prevents this. I have only seen one time when a gate was forced open during a coast down and that folded the shutter blade in half and stripped the bronze gear. Also be sure the oil filter and magnet are clean. Do not use red auto parts store rags to wipe down anything in these projectors! I've seen the filter become completely clogged up in just several running hours! These rags have some sort of loose lint on them and is is nasty stuff. Added: Also note that the vert. shaft IS NOT HARDENED. This makes for gauling being more of a problem if oil flow is reduced. Also be sure gear mesh is proper. I've seen many many DP-70 with very loose gear mesh. Yes, I agree. The JJ is a Fisher-Price version of this projector... Just a toy. The Simplex... well... built by Mattel! (Edited version 1.02) Mark  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 06-08-2010 02:11 PM                     quote: John Walsh And of course, I have no control over the operators. Actually I'd like to find some other reason for this, if there is one. I'm wondering why it's happening three times in a short time.... There is no other reason for so many repeated failures in such a short time. 100% operator negligence. If there were any problems with the projector mechanically that would trigger those failures you would hear it as soon as you started the machine. AA's are so smooth and quiet that any impending issues would be very easy to hear.  |  IP: Logged

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