P3D Re: HELP! The Projector Ate the Slides!

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

Could it just be hungry? :-)

>Problem: Projector gets hot and the mounts melt (literally). The worst 
>was seen in mounts that were used backwards (i.e. the black side was 
>towards the light), but a milder form of the problem was also seen on 
>the white sides.

>Has the projector malfunctioned? Should it be overhauled? Can any type 
>of glass be installed as a heat shield between the bulbs and the images? 

I have done extensive experiments with TDC projectors, 750 and 500 W
bubls, and published the results in P3d about a year ago.  I used
a thermometer to measure the temperature at the film gate.

These projectors have heat absorbing glasses.  If the glasses in your
projector are missing or replaced with plain glass then you are in
trouble!  Even with the proper glasses on you should avoid projecting
RBT mounts with the black side towards the lamps.  Black absorbs
heat like crazy and temperature goes up.

Will try and find my data and repost them.  In the meanwhile please
open the projector and locate the heat absorbing glasses. Make sure
that they are there!!!  If they are missing, stop using the projector!

>Do we stop showing RBT mounted slides on the TDC?

Certainly *my* RBT-mounted slides!!!! :-)

George Themelis


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