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Author Topic: Need Advice Converting Carbon Arc Lamphouse to Xenon Will Kutler Phenomenal Film Handler Posts: 1506 From: Tucson, AZ, USA Registered: Feb 2001 posted 07-10-2003 07:34 PM                     Here is an off the wall question for someone to answer, thanks to the bullshit politics of our local city government, which has banned the indoor use of carbon arc, claiming that it poses multiple hazzards. So, to maintain an aesthetic appearance of a restored booth that would require more wattage than I believe the Kniesly and LPA Xenon conversions would be capable of, is it possible to insert the guts of a Strong Lume-X or Christie unit into a Magnarc or Strong Utility Lamphouse?  |  IP: Logged Jon Miller Jedi Master Film Handler Posts: 973 From: San Diego, CA, USA Registered: Sep 1999 posted 07-10-2003 09:09 PM                     Sorry to hear about your situation, Will . Ill-advised politicians just love to take all the fun out of things, don't they? Anyway, it looks like you may have to bite the bullet and install a proper xenon lamphouse. AFAIK, the xenon conversions you mentioned are no longer made for safety reasons. Also, getting that square peg of a plenum assembly from a later Christie lamphouse into the round hole of a Magnarc would be somewhat of a challenge. Proper cooling airflow for the lamp would be another issue. To me, an old carbon-arc lamphouse with a xenon conversion is like a vintage car with a more modern engine under the hood...it just does not have the same feel and would not be as satisfying.  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 07-10-2003 09:44 PM                  Will, what wattage xenon lamp do you think you will need? >>> Phil  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 07-11-2003 05:11 AM                     The usual conversion of a Magnarc lamphouse in this country was done my Morganite / Thorn EMI and used a standard E53 mirror. This involved removing all of the original carbon rod mountings and gearing, extending the mirror support on rods some 6" or so forward and mounting a support assembly for the lamp with a focus control rod sticking out the front. Whilst these were used in every ABC and many Odeon and independant cinemas I thought they were awful. Any adjustment of the mirror moved it sideways or up and down so it was seldom, if ever, set up perfectly. The only way they could be setup was on the bench in the workshop. Real dogs... The other conversion was done by a guy called Bernard Bently and sounds like it would be ideal for you. The Magnarc was left mostly untouched apart from the negative end of things which was removed entirely. The positive carrage was used to mount and clamp the lamp using the original feed control for focus. The mirror was a full sized cold glass mirror with an aluminium ring held loosly in the middle by a spring that the lamp rested on and slid back and forth on when focused. This method also allowed for expansion of the lamp. The strike unit was mounted inside the rear negative access door. A small external box contained ammeter, neon, hour meter and manual strike button. The light off this was very smooth with no hot spots at all. Being a cold mirror I'm sure it could have been used up to 3k easily. The only noticable difference looking at the lamphouse was the missing feed motor and pusher rod for the negative feed. Sorry I can't give more help but I'm sure someone on here may have more information for you.  |  IP: Logged Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 07-11-2003 07:38 AM                     I looked into converting our Magnarcs before replaceing them. The Kneisley conversios were good for a max of 2000 watts and from what I was told by two people who had used them that they should be avoided. The convs haven't been made in more than 20 years and if you needed parts you can't make your self Kneisley no longer has any. I did see a while back a completely gutted Magnarc with ,what I believe was a 1600 watt xenon assembled inside the shell.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 07-11-2003 07:51 AM                     Well I know lots of people say its not a good thing, but seriously look into Metal Halide lamps. I am going to convert an ARC lamphouse into a Metal Halide lamphouse. Many have 4-7mm arc gaps so the orginal mirror can be used and with 6000k colour temp on many of the lamps makes it worthwhile with brightnesses around 110 thousand lumens. A lamp not quite that bright is around the $300 AU mark. Not sure what people have against Metal Halides. I am also going to hopefully convert an ARC slide projector to a smilar system, but with a cheaper lamp that produces 40 000 lumens.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 07-11-2003 08:59 AM                     Bernard Bentley used the Kniesley Kit The metal Halide is an AC arc and unless one uses a square wave ballast you will get beat flicker  |  IP: Logged Jim Spohn Film Handler Posts: 95 From: Bakersfield, CA, USA Registered: Jan 2003 posted 07-11-2003 09:25 AM                     Will...I have two Magnarc lamphouses with power supplies that have been converted to Zenon that I would part with if your interested.....Jim  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 07-11-2003 02:51 PM                     Xenon lamps can evolve ozone, and they can explode. Those are multiple hazards, so why haven't they been banned as well?  |  IP: Logged Will Kutler Phenomenal Film Handler Posts: 1506 From: Tucson, AZ, USA Registered: Feb 2001 posted 07-11-2003 04:34 PM                     The requirement for this application would be much greater than 2k watts (which is what the LPA and Knisely were rated for). This is why I was wondering about being able to mount Strong or Christie guts into those c/a lamphouses. But thanks for the info everyone. I have made some recommendations to the powers that be...and the final decision is up to them.  |  IP: Logged Stan Gunn Expert Film Handler Posts: 176 From: Clematis, in the hills near Melbourne Australia Registered: Aug 2000 posted 07-12-2003 03:03 AM                        Will I have seen a 3k conversion on a peerless some years ago; all the oridgenal parts mirror etc were left intact only the carbom holders removed, it was reported to have had exelant light output. I have fitted smaller lamps to a viarity of lamps for back yarders also with good results, A little lateral thinking goes a long way. Stan.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 07-12-2003 04:46 AM                     That is true Gordon, about the square wave ballast, should not be too big a problem. What about AC arc lamps, how did they get past the 50/60hz flicker? I will post pics once I am done with my lamphouse and show people it CAN be done. I belive nearly anything is possible, just a bit of imagination is needed.  |  IP: Logged Fred Georges Master Film Handler Posts: 257 From: Lombard, IL, USA Registered: Jun 2000 posted 07-12-2003 09:27 AM                     I remember seeing a 1940's Arc lamp called a "Super Cyclex". It was an AC arc that used high frequency conversion in the power supply (No "rectifier" necessary) to avoid beat flicker. As an added bonus this thing could burn a bit over two hours on a single trim. Interesting.  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 07-12-2003 09:59 AM                     Converting a Magnarc to xenon isn't very dificult, I did that before and it was basicaly what Ken said in his post, the negative end goes away and the positive is kept to be used as a bulb suport(sp?).Nothing was changed in the mirror holder, only a block of heat resistant,insulating material was added in the centre hole of the mirror.a small "squirrel gage" type fan was mounted on the rear door for bulb cooling (was going to add another on the side, at the same place of the view glass but it'd flow right over the glass ball and not at the metal end. About the metal halide bulbs,( HMI types) I also did two conversions to it, the light is about the same in color temp , I didn't really notice any beating due to AC.Both are in use for projection with small screens then I think that's why nothing was noticed. I'm not sure about the results with a larger screen. In both cases the bulbs where 1200W.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 07-13-2003 12:02 AM                     Great to hear HMI lamps can be used! Very interestin about the "Super Cyclex" Arc lamp, amazing what people think of, strange it never really took off though!? Luciano, do you know what model the Metal Halide lamp you used was? If it was 1200watts, that would be around the 110 000 lumen mark, you used that much light on a small screen? How small a screen? Whats the lamp life like? Which is cheaper, Metal Halide or Zenon, including rectifier/ballast?  |  IP: Logged

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