8mm Forum: maintenance of a GS 1200 Xenon

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Posted by Jean-Philippe Rolland (Member # 314) on April 07, 2008, 08:31 AM:

Dear All,

I have bought a GS 1200 Xenon a few years ago. It was hardly used. I did not use it much myself. Everything seems to be working fine but I am wondering what usual and basic tasks I should carry out to keep it in good repair.

The neophyte I am will welcome any advice

Many thanks

All best

Jean-Philippe Rolland

Posted by John Clancy (Member # 49) on April 08, 2008, 02:56 AM:

Others will no doubt have better advice to give than I but I find the best way to keep them running sweetly is to use them occasionally. If I leave one for several months I find they can develop problems. A bit like classic cars really.

Posted by Graham Ritchie (Member # 559) on April 08, 2008, 05:00 AM:

More of a question than anything else regarding Xenon lamps, is there some means on the GS1200 of keeping a record of the lamp hours?, and are you increasing the chance of lamp explosion by using them well past there recomended life?, what does a lamp cost? and how long is its life? I dont own a Xenon projector but was wondering how owners of them get on, I look after the 35mm projectors at work and we keep log books on the Xenon lamps fitted to projectors and change them at the time recomended by the lamp manufacturer. Is it something that owners need to be aware of or not regarding Super8 as to the dangers of Xenon lamps in general.

Graham.

Posted by Maurice Leakey (Member # 916) on April 08, 2008, 09:10 AM:

How many owners of Xenon lamp projectors have the required clothing to use when changing lamps. I know this sounds silly but has anyone seen a Xenon lamp explode?

Posted by Simon McConway (Member # 219) on April 08, 2008, 10:05 AM:

I know there's serious risk regarding xenons exploding. I have two Elf 2000A 16 mm projectors and these use 300w xenons. Basically, you need a welder-type face mask and even a chemistry lab-type apron in case these lamps were to shatter during changing. I've heard the pressure inside these lamps is several atmospheres! You don't want to drop one of these! However, whilst they're installed in the machine (usually designed to take the force of an exploding lamp) you're unlikely to get hurt if the unthinkable happens. But let's not exaggerate by offering scary stories about audiences being showered with glass. This wouldn't happen, though they may be shocked at the noise of the explosion. I heard one collector talking about a time when the xenon blew at Blackpool whilst The Late, Great Derek S. was showing film. Take care when carrying xenon projectors...and even more care when lamp-changing, and you'll be okay.

Posted by Graham Ritchie (Member # 559) on April 08, 2008, 01:48 PM:

Just as an example on 35mm, if a lamp manufacturer rates the lamp for 2000 hours we can exceed that but only up to one and a quarter its recomended life which makes it about 2500 hours after that point the risk of explosion they say increases, although Xenon lamps are contained in the projector they can do a lot of damage, in 35mm they can destroy a very expensive mirror, at work I wear all the safty gear when changing them and treat those lamps with great respect even in there cold state, so how does all this reflect to the lamps used in Super8 or 16mm projectors? how do you keep a record of lamp life?

Graham.

Posted by Graham Sinden (Member # 431) on April 08, 2008, 04:17 PM:

Just a question, but does the HTI lamp have the same risks or are they safer?

Posted by Paul Adsett (Member # 25) on April 08, 2008, 06:14 PM:

And don't forget about video projector lamps, which are pressurized to 200 atmospheres!

http://www.ercservice.com/lamps/philips/PhilipsUHPLamps.html
http://www.lamptech.co.uk/Spec%20Sheets/Philips%20UHP120.htm

Posted by Paul Adsett (Member # 25) on April 08, 2008, 06:16 PM:

And don't forget about video projector lamps, which are pressurized to 200 atmospheres, or 3,000 psi!

How do you dispose of the lamp! [Eek!]

Posted by Kevin Faulkner (Member # 6) on April 09, 2008, 07:45 AM:

These are all very interesting questions and I for one have no idea how many hours the lamp in my GS has been running in total. There is no facility on the GS for totting up lamp hours but I'm sure that a timer could be incorporated into the GS which would count up while the lamp is running.
I have changed a few of the xenon lamps and it seems to be they get bad at striking before the lamp is so worn out that it could explode. They are changed from the annoyance factor of difficult striking.
The lamps are the same as any other xenon lamp just smaller than your average cinema machines lamp so the same safety precautions should be observed and the same rules about life would apply.
I would think the same goes for the HTI lamps. Any lamp which is under pressure carries the same risk of explosion as is any lamp which has a vacuum or negative pressure such as the std CRT we watch most evening. Handling has to be carried out sensibly.

I never move my GS until the lamp is extinguished and cooled down and try not to knock the machine while it is running.

I thought this was an interesting read: Short arc lamp safety

I'm not sure of the GS 1200 xenon's expected lamp life. Does anyone have that info?

Kev.

Posted by Jean-Philippe Rolland (Member # 314) on April 09, 2008, 08:28 AM:

Thank you very much for these fruitful information.

Last weekend I removed the dust, in a gentle way but with a small compressor though. I must have been out of my mind all the more as it was not very dusty anyhow.

I am lucky that the bulb did not burst.

I think I will buy a S 940 by Eumig to spare the GS, if I can find one.

There is one in Austria but it is too expensive, ie 450 euros.

Have a nice day

Jean-Philippe

Posted by Alan Rik (Member # 73) on April 09, 2008, 09:02 AM:

No need to spare the GS! Just keep using it..that's what it was designed for and enjoy the pure white Xenon light. [Smile]

Posted by Kevin Faulkner (Member # 6) on April 09, 2008, 11:48 AM:

I agree with Alan. I have a spare lamp by me just in case.

Superior Quartz have the lamps if you need a spare. Yes we talk about exploding lamps but that is not an everyday occurrence.

I used to have a std GS with the 200W ESC lamp but after owning the GS Xenon I never used the std machine...I wonder why?
Once you see your films with a Xenon light source you will never want to see them with a tungsten lamp as they will look dim, dirty and yellow.

Enjoy that GS Xenon. Just keep the film path clean and check the various film guides for wear and all will be ok.

Kev.

Posted by Clive Carmock (Member # 347) on April 09, 2008, 06:05 PM:

I'm not sure if this is actually right, but might be worth further investigation. I have read that the smaller power Xenon lamps are much less likely to suffer an explosion than the larger ones used in 35mm machines. If that's the case then the 250W Xenon in a GS1200 shoudl be reasonably safe. I must admit if changign it I still would be careful to protect myself as much as possible.

LIke Kevin I too have a spare lamp for my GS which I got from Superior Quartz. Kev am I right in saying they are now the only source of lamps suitable for a GS1200?

I believe they manufacture them specially for this machine. I think the Elmo 16mm Xenon machines used the same lamp ?

Clive

Posted by Simon McConway (Member # 219) on April 10, 2008, 01:59 AM:

After all that talk about GS1200 Xenons, I'd like to buy one. Can anyone sell me one?

Posted by David Kilderry (Member # 549) on April 10, 2008, 05:41 AM:

The smaller the xenon the longer the life. We get only about 800 hours out of our 5,000 watt xenons, but smaller lamps of less than 2,000 watts can last several thousand hours.

The 350 watt in the GS 1200 would have a rated or warranted life of around 2500 hrs at an estimate. The bulb supplier will have this information on the papers sold with each xenon.

One thing to remember with xenon arc lamps as opposed to QI lamps is that their light output deteriorates from day one and continues to degrade with every usage hour. They will not blow in the way regular QI lamps in most Super 8 projectors do.

Without knowing your usage hours it is therefore difficult to know when to change it. All 35mm and 16mm lamphouses have hour counters. If you have had the same xenon GS 1200 for over 10 years and never changed the lamp; replace it and you may be amazed at how much your light output had dropped over the years!

David

Posted by Simon McConway (Member # 219) on April 10, 2008, 05:52 AM:

On my Elf, the paperwork says the Xenon will keep up to 99% of its original brightness until the day in fails.

Posted by Kevin Faulkner (Member # 6) on April 10, 2008, 06:05 AM:

I believe that Keith Wilton had one of the 250W GS xenon lamps blow at the BFCC some years back. I have to say that I wasn't there to witness this spectacular event.

I changed a Xenon lamp for another member on the forum recently whose GS1200 was becoming a real pain to strike. The striking time is very important because if the power supply keeps ticking over trying to strike the lamp it can cause the power supply to fail. Anyway the difference in light output was quite amazing and needless to say the owner was over the moon with the increased brightness. My own machine normally has the lamp up and running within a second or two but this machines new lamp was virtually instant.

I have a spare genuine Elmo replacement lamp but it doesn't have any paperwork to say what the lamp life is. I always understood it to be on average about 2000hrs and I know mine is nowhere near that yet.

Putting a counter on the GS wouldn't be too hard a job to accomplish but it would be difficult to find the space in the machine to mount it. These xenon machines a fairly full inside.

Anyway I would just use your machines and enjoy that super bright white light which really makes the colours pop off the screen especially the Derann Disney's [Smile]

Yes Clive, Superior are the only makers of a lamp for the GS and yes its made specially. It's nice to know we still have a supply of them available. [Smile]

Kev.

Posted by Dimitrios Kremalis (Member # 272) on April 10, 2008, 02:58 PM:

Btw Kevin, do you remember those lamp changing instructions?? Whenever you find some time.. [Roll Eyes]

Posted by Jean-Philippe Rolland (Member # 314) on April 10, 2008, 04:10 PM:

Thanks to Kevin, I was in touch with a very nice guy from Superior Quartz.
He asked me to remove the bulb, measure it and take a snapshot so that I can order a spare one. There are two lengths available.
He also mentioned that should the bulb explode, it would not cause much harm or damage because of its small seize.
I forgot to ask him the 'life expectancy' of such a bulb but I will do it next time.
by the way, there is a nice GS -not the Xenon version- available in a thrifty shop in Paris. It is like new against 450 euros.

Have a nice evening

Jean-Philippe

Posted by Patrick Walsh (Member # 637) on April 10, 2008, 05:55 PM:

I have had a xenon explode on me before, It was a 7kw in a KINOTON FP30D 35mm projector, I was working as a projectionist at a 8 screen multiplex, and one night while running the film ROBOTS the thing exploded, it took all the inside of the lamphouse and mirror with it also the heat filter between the lamphouse and projector head, also scorched the lino floor around the projector with the glass flying everywhere and it made a hell of a boom, The lamp was not old but we worked out it must of been the lightning storm outside that caused it to blow, a sudden rise in the mains to the lmaphouse may of caused it we think????.
As Graham and the others said a mask and a saftey jacket and gloves is a must.
still prefer carbons though for 35mm presentations [Smile]

a more natural light [Smile]

Pat

Posted by Kevin Faulkner (Member # 6) on April 10, 2008, 06:25 PM:

Glad that helped you Jean P.

Dimitrios, Sorry I forgot once again. I will sort that info for you this weekend. I seem to get too involved with Elmo repairs etc these days and forget the other things I need to do.

You have my email address just keep reminding me [Big Grin]

Kev.

Posted by Dimitrios Kremalis (Member # 272) on April 16, 2008, 05:12 PM:

Mr. Elmo perhaps this weekend? [Roll Eyes]

Posted by Kevin Faulkner (Member # 6) on April 16, 2008, 06:19 PM:

I'll try my best for you. [Wink]

Kev.

Posted by Paul Stanley (Member # 1109) on April 17, 2008, 05:02 AM:

The Xenon lamps we have in our 35mm machines here reach around 5900 deg and the end life of a Xenon is when the UV output has decreased around 30%. Xenon lamps should be changed when you have used over 25% of this to be on the safe side and yes we have seen them blow. Thats the technical stuff from one of our technicians here who I asked this morning about these type of lamps.

Posted by Tom A. Pennock (Member # 202) on April 17, 2008, 10:19 AM:

I think John Clancy made an EXCELLENT point about using our projector's. Yes, it is indeed about like driving classic car's every so often to keep them in top shape. I have six Bell & Howell 16mm "brand new" unit's and two Eumig's and one Elmo. I think I probably should take ALL the brand new Bell & Howell's out of the factory sealed cartons and indeed run them. I thought about just leaving them "brand new" in the factory boxes for the future. But they probably should be run without any film at all to just keep them going every so often. I think I will indeed keep a chart in regard's to this and run the unit's every so often.

Thank's John for this excellent idea. Otherwise I think the brand new unit's might very well lock up even when never ever used.

Best, Tom

Posted by Hugh McCullough (Member # 696) on April 17, 2008, 05:13 PM:

Video of a cold exploding Xenon lamp
http://www.youtube.com/watch?v=SVpD8SWzKFM

The idiots involved were very lucky not to have had more damage inflicted on them.

I had a brand new 4K lamp explode in the lamphouse between changeover cue dots.
It would happen on a Premiere, but luckily I was running on reels, and had a third machine so I did not have to replace the lamp, and diachroic mirror in a hurry.

If handled properly, and only exceeding the lamp life by about 25%, the modern lamp seems to be very stable.

Posted by Graham Ritchie (Member # 559) on April 17, 2008, 08:02 PM:

Hugh
That is one very scary video I got a call one night from the cinema as the projectionist that was on had one go "BOOM" as he dropped it while handling it outside its protective sleeve although he had put a welding shield on which is not enough protection he landed up at A/E with cuts and stiches to his hand. The next day I came in and found bits of glass everywhere [Eek!]

and as far away as 30ft, he was very lucky I alone now look after the Xenon lamp changes, if a piece of glass was to hit someone say in neck on a main artery that person could be dead in minutes although the chance of of one going "BOOM" is slim accidents can still happen.

Graham.

Posted by David Kilderry (Member # 549) on April 18, 2008, 04:51 AM:

I should have said earlier that the smaller the xenon (like GS 1200), the more stable the lamp ie less chance of an unexpected explosion. We used 350 watt xenons in the Hokushin 35mm slide projectors for years in various cinemas.

Striking difficulty generally means the lamp is nearing the end of its life, but does not necessarily mean it is about to explode. The lamp should strike first go, big or small.

All xenon lamps lose light output as they age, the larger the lamp the steeper the fall-off curve. Xenon lamps do not like hot strikes, they need to cool for around 10 mins and strike cold to preserve their life.

When I was part of the worlds largest cinema operator outside the US, we had Ushio (Christie is USA) from Japan work with us direct on xenon training seminars and had access to their factory labs for some of our failures. They are a very professional organisation with decades of xenon manufacturing experience. We learnt a great deal from them; after all back then we purchased thousands of xenon lamps every year!

Posted by Kevin Faulkner (Member # 6) on April 18, 2008, 08:03 AM:

Pretty scary stuff. Did you see his hands and face afterward [Eek!]

Kev.

Posted by Dimitrios Kremalis (Member # 272) on May 01, 2008, 11:20 AM:

Weekend is coming, time for some lamp changing instructions?? [Big Grin]

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