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Author Topic: Strong Arc lamps
Phil Krikau
Film Handler

Posts: 1
From: San Francisco, CA, USA
Registered: Nov 2002


 - posted 06-07-2004 04:34 PM      Profile for Phil Krikau   Email Phil Krikau   Send New Private Message       Edit/Delete Post 
Does anyone know of where I can locate the glass reflectors for the Strong rotating positive arc lamps. I'm also looking for the 11mm contacts. Please email Phil-K@webtv.net

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 06-07-2004 08:04 PM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
Phil, I think it is time to convert to Xenon. The reason I suggest this is because the jaws are made of silver - and the last time I changed them in a Strong (or any other rotater) the client was billed 600 bucks for the jaws. That was 20 years ago...

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 06-08-2004 05:54 AM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
Besides, I might have a mirror to fit it. If it is the right mirror, you can have the damn thing if you pay the postage. If I recall correctly, it was from a Strong Futura II. I thought it was a 13.6mm black stick that mine used. Can't be sure of that though. I bought them as junk. The mirror I have is a cold mirror, and is in almost perfect condition. BUT ONLY IF IT IS WHAT YOU NEED!!! I will take your word of honor. [Smile]

If not, I want to keep it for someone else that might need it.

Is this what you need?
 -

[Big Grin]

Email me if you need more specifics. The monitors in the background are 21 inches so that will give you a rough size of the mirror. Please provide me with the diameter of your mirror, and the depth of the curvature.

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Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 06-08-2004 06:36 AM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
You might be able to find somebody who has converted, and still has their old lamps in store, who may let you have some old jaws that still have some life in them. A lot of old cinema equipment seems to be left in store when it is taken out of service, behind screens, in rectifier rooms, etc.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 06-08-2004 07:26 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Wolk might still have some silver jaws left around. Give Juan a call there. I can remember the ole days when Charlie kept the silver ingots for making the jaws for Strong and Ashcrafts in a big safe cause some employee of his walked off with the stash of them once [Eek!] .

Mark @ CLACO

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999


 - posted 06-08-2004 08:33 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
The Futura II took either 13.6mm or 11mm positive carbons. The positive drive determined which you could use and were stamped on the face of each drive roller.

Steve

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003


 - posted 06-08-2004 09:31 AM      Profile for Sam D. Chavez   Author's Homepage     Send New Private Message       Edit/Delete Post 
There were jaws for 10mm as well. They had air cooled jaws as well, which made burning carbon butts a real adventure.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000


 - posted 06-08-2004 11:45 AM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
What if you machined some jaws out of copper? Would it melt (assume water cooling)? How about some other high melt metal and just deal with the greater resistance...maybe increase the contact area proportionally? Or perhaps something akin to motor brushes to take some of the job of getting the current into the rod.

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Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 06-08-2004 12:31 PM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
Pure copper melts at 1098°C if I remember correctly. That's fairly high; brass melts at something like 850°C, depending on its exact composition. I don't know the melting point of silver, but I have a feeling it is lower than copper.

http://www.webelements.com/webelements/elements/text/Ag/heat.html tells me that the melting point of silver is 961.78°C

I don't know how much additional heating you would get due to the increased resistance, but copper is a pretty cood conductor.

The Loew's Jersey managed to get new silver jaws for their Ashcraft lamps, but I don't know where from.

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Martin Risher
Film Handler

Posts: 13
From: Monroe, Washington, USA
Registered: May 2004


 - posted 06-08-2004 01:03 PM      Profile for Martin Risher   Email Martin Risher   Send New Private Message       Edit/Delete Post 
Hey, by the way!
Whats the best way to get those reflectors clean? Alche-ma-hole? Windex? A guy i know say he uses lens cleaner, but im a little unsure...

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 06-08-2004 01:19 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
My guess would be that the corrosion characteristics of copper would be an issue for good electrical contact with the carbon, or it would have been used.

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003


 - posted 06-08-2004 07:02 PM      Profile for Sam D. Chavez   Author's Homepage     Send New Private Message       Edit/Delete Post 
I believe Silver oxide is actually a better conductor than the Silver itself, or so I've heard. You don't see any copper contacts in relays for a reason.

Any silver cleaner will work if you want them to look pretty, certain Anal operators in my past lihe in the booth used to get them to shine like well, Silver.

Bon Ami was also used at the time to clean them

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000


 - posted 06-08-2004 09:07 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
Yeah but Bon Ami wouldn't get the bloodstains off the ivory in The Ghost and Mr. Chicken. Amazing the useless things one retains. Atta-boy, Luther!

I think copper relay or switch contacts would weld themselves or otherwise erode from the arcing that occurs as they part under load. That wouldn't be the case with carbon contacts. I'm sure there's a reason they didn't resort to such a cheaper alternative but then it wouldn't be difficult for someone make up a set out of copper and give it a shot and let us know.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 06-08-2004 10:33 PM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
Deleted by me.

[ 06-09-2004, 02:22 AM: Message edited by: Paul G. Thompson ]

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