Film-Tech Forum ARCHIVE: Will changeover shutter handle 2k bulb running all the time?

This is topic Will changeover shutter handle 2k bulb running all the time? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Brad Allen (Member # 470) on 05-02-2005, 11:50 AM:

Will the change over shutter on a Simplex 35 handle the heat of a 2000w bulb running between shows? This would be anywhere from 20 minutes to an hour.

Posted by Steve Guttag (Member # 268) on 05-02-2005, 12:10 PM:

No...the changeover shutter in most projectors are only rated for less than a minute exposure to the intense and concentrated heat from the lamphouse. There is a trade off of durability and mass...less mass makes for a quicker operation and more seamless in a changeover environment. Note, if you have Strong brand consoles or lamphouses, those dousers may be motorized.

Posted by Monte L Fullmer (Member # 2797) on 05-02-2005, 12:51 PM:

..blades are pretty thin. I had to change out 6 of these blades with quarter-inch holes burnt into them due to one 8 plex's projection staff leaving the bulb on due to "faulty startups", thus turning on the cue fault switch on the CNA-100's. -Monte

Posted by Kevin Orman (Member # 3076) on 05-02-2005, 01:14 PM:

Does anybody know if the 'electric' dowser on a Vic 5 can stand the heat with the main dowser open with 1.6kw lamp? I'm not sure if this is intended to be for change-over only or used as a normal dowser. We have been operating one of these for just a few shows so am not overly familiar with it yet. I usually open and close the show with the manual LH dowser but I'm not sure the part-time projectionist does though..

Posted by Stephen Frazza (Member # 2320) on 05-02-2005, 09:06 PM:

When I first started working where I do now one of our Strong X-90 consoles with a kelmar douser had a problem with the automation and the bulb had to be lit manually.
So the other projectionist would just turn the bulb on in the morning and leave it on all day.It would stay on in between shows and even if he didn't start a show during a weekday it will still stay on for hours with just the changover closed.
Only difference was that it was only a 1600w bulb.It was like that for months and we never had a problem.

[ 05-06-2005, 01:36 AM: Message edited by: Stephen Frazza ]

Posted by Mark Gulbrandsen (Member # 72) on 05-03-2005, 07:45 AM:

If they were made of titanium they would easily last...... That small of piece is not really all that expensive, its just alot more difficult to machine the stuff.

Mark

Posted by Richard May (Member # 2627) on 05-03-2005, 07:54 AM:

As long as the lamphouse douser is closed between shows, you can leave the lamp on all day. Even with the douser opened, we have left it shining on the changeover shutter for up to a half hour at a time with no problems. I'm sure that if it was done continuosly, it may burn through.

Posted by Mark Gulbrandsen (Member # 72) on 05-03-2005, 10:38 AM:

Some will warp(Century and Christie), while some will burn right through (Simplex). The warped ones tend to cause more problems as sometimes they become stuck shut. Stainless steel just doesn't cut it for changover blades in the long haul.

Mark