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Author Topic: Slight strobing on Christie SLC lamphouse with Simplex Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 10-18-2008 06:38 AM                        I have a Christie SLC 30 lamphouse which lights our large giant screen and entertains millions of patrons each month. Attached is an ancient Simplex XL projector. Both components work fine, but if you look closely there seems to be a very slight strobing going on. The lamp itself is fine. This auditorium has pretty much always done this since these two components were installed. As far as I can tell there doesn't seem to be any problems with the power supply (this is absolutely nowhere near as bad as if a diode went out). The console is receiving proper "3-phase". The shutter seems to be in time. But since this vintage of Simplex is fairly old (late 60's maybe), would it be advisable to replace the shutter to something that allows a bit less "black time"? My biggest problem with the newer/shaved Simplex shutters is that it can be a real pain to eliminate all ghosting. EDIT: Crap, I thought I was in the FHF. Please move! [ 10-18-2008, 08:27 AM: Message edited by: Mike Olpin ]  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 10-18-2008 06:47 AM                        Joe; the SLC has quite a bit of energy in the corners (and above the top, below the bottom, and left and right of the sides. It is unique in only that way. Look at the shutter blade with a strobe light set to 1440 pulses. See if there is any "bounce." I think you will find a very slight mechanical problem, perhaps with a noisy, but not quite audible, bearing in the shutter assembly. Louis  |  IP: Logged Mike Olpin Chop Chop! Posts: 1852 From: Dallas, TX Registered: Jan 2002 posted 10-18-2008 08:27 AM                     MOOoooved.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-18-2008 09:34 AM                     Louis, I don't think Joe owns a set of allen wrenches let alone a variable strobe.... Mark  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 10-18-2008 10:08 AM                        Thanks Mike. LOL @ Mark. He is right that I don't own a strobe, but I see what Louis is suggesting. I have a bunch of other idle Simplexes laying around that were removed and replaced with Simplexes (not a typo). They worked fine for the most part. I could rob parts from them, maybe I'll dig the one out of the trash from my avatar. I'll look for the noisy yet not audible bearing. Mark, why would anyone need any other tool than an adjustable crescent wrench?  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 10-18-2008 01:22 PM                     And a ball peen hammer for the finer adjustments!  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 10-18-2008 01:41 PM                     LOL at the other foolishness posted so far... Joe: Here are the things you need to look (and listen) for: Shutter blade warped; Shutter cut correctly (there should be no more than 2-4mm of material between the bottom of the opening and the hub); Bad shutter drive assy (While looking thru the glass on the gearbox side, have someone start the projector. If you can see the metal drive gear on the shutter drive bounce or oscillate as it starts, the shutter drive needs to be rebuilt.) Sometimes you can also hear a knocking as the machine ramps up when this dirve is bad. A two-blade shutter tends to strobe or flicker, especially at higher illumination levels. If you're currently running the bulb near the bottom of it's rating and getting adequate light, you could put in a three-blade shutter and get rid of that strobing. Finally, it is remotely possible that you still have an incoming power problem..a loose connection or bad breaker can still pass enough voltage to give good readings on a voltmeter, but any arcing from that loose connection will give unsteady light. Are any of the breakers to the rectifier hot or warmer than other screen's rectifier breakers? I think you'll find a warped shutter blade though.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-18-2008 03:39 PM                     quote: And a ball peen hammer for the finer adjustments! Or a sledge hammer when things are getting really critical! Really, hows about starting at the source guys... like the lampenhousen. First be sure that all is well there... That the DC is good, that the illunmination on the screen is not too bright and causing the flicker... yea right Joe... that takes a screen brightness meter... not found in the same trunk as the crescent wrench! Harkness makes an el-cheapo that'll get you in the ball park. Just don't hit any foul balls... P.S. Tony makes a good point about the incomming power. I've seen Christies really flicker if you have a high leg AND the brightness is too high! Mark  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 10-18-2008 07:48 PM                        It's a 3000 watt lamp attempting to light a 30 foot screen. I even does this in flat. Sure, the image on the screen is brighter than the sun and sharper than a razor's edge, but, ummm yeah. I don't think I'll find a warped blade. The pattern is a bit too irregular for that and not at all quick enough. Incoming power could definitely be an issue. Since this is our large giant screen, no other screens in this complex dare be as large or as bright, so no other screens use this kind of immense power so of course the breakers will be warmer.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 10-19-2008 08:15 PM                        Ooo double post! Well it definitely doesn't seem to be anything BEFORE the projector that is causing this. The light on the screen is steady as a rock without the projector in motion. This morning I opened the changeover and rotated the shutter into position and shined the light onto the screen and nothing moved/strobed/flickered at all. I left the light on the screen for 45 straight minutes just to be sure. When the movie is running the strobe is greater on the left hand side and it is not at a constant pattern... though close. It almost looks like bulb flicker in many respects, but it isn't. PS - Suddenly my onscreen image is all hazy and lacks much detail and contrast. It looks awful. This just started today when I started the first show.  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 10-19-2008 09:01 PM                     Well Joe, If you left the projection lens in the machine during your 45 minute light test it has probably gone to glass heaven. When there is no film in the light path, there is excessive light and heat to the lens. Also the lack of shutter blades reducing the amount of light will ultimately destroy a projection lens. Raw light should only be allowed to pass through the lens for a few seconds while making focus and flatness tests for the lamp. There is a very good chance that you will need to install a new lens to correct your problem. Best try another lens in that machine. KEN  |  IP: Logged David Stambaugh Film God Posts: 4021 From: Eugene, Oregon Registered: Jan 2002 posted 10-19-2008 09:07 PM                        Ken, I suspect Joe is messin' with us.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 10-20-2008 08:53 PM                     Shutter, shutter, shutter!!!! Bad shutter drive or warped/damaged/burnt shutter. quote: Joe Redifer ....Sure, the image on the screen is brighter than the sun.... It's also (with this revelation) possible that you have TOO MUCH LIGHT on the screen. My room at UC Irvine has a 26' wide (scope) picture and I get an easy 16fl using a 1600 watt lamp. (Kinoton). Anyone local to Joe with a spot meter to check his light?  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 10-20-2008 11:04 PM                        There is less light on this screen than our smaller houses. I know what the "too bright" strobing looks like and it isn't this. The shutter looks fine. I cannot locate this noisy/inaudible bearing.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 10-21-2008 12:39 AM                     When you take the shutter guard off and move the shutter, any vertical/lateral play in the shaft itself? Or, is the fibre gear that drives the shutter gear, is it okey? Also, what about the vertical shaft - is it aligned (anyone over there had a bad brainwrap causing the machine to work real hard which can knock off the alignment of the vertical shaft assembly?) where all the contacting gears have the correct clearance between the teeth? -just some thoughts.... - Monte  |  IP: Logged

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