8mm Forum: Eumig P8 bulb cooling

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Posted by Thomas Dafnides (Member # 1851) on December 24, 2009, 09:53 PM:

I have been running an Eumig P8m which has a very impressive picture...makes standard 8 look like 16mm. My question for other owners is that I am surprised by how weak the cooling is in the lamp area, putting your hand over the rear vent and I feel only the weakest breeze...is this normal for this machine?
Even after removing the top vent and the bulb and then putting your hand into the bulb area, one only feels a faint breeze when running the projector.

Posted by Steve Klare (Member # 12) on December 25, 2009, 10:36 AM:

Hi Thomas,

I guess the bottom line here is, is the cooling air sufficient or not. If it isn't you will find yourself changing the bulbs very often.

On the other hand if it was excessive it would be like watching films with a little jet engine in the room. Most of the time when I work with fan cooled equipment there is a spec for noise: you get enough loud fans in a room the sound can be disturbing. Also electric fans are the least reliable part of most electronic systems they are used in, and the harder you work 'em, the sooner they'll fail. It’s always better to run a fan at less than max output.

It's possible Eumig was bearing all this in mind and kept the cooling air flow sufficient, but on the low side. They certainly knew their business.

Maybe what you should do is make sure the internal cooling air passages are free of dust, lint and other obstructions and if your bulbs last a satisfactory period, don't worry a lot about it.

Merry Christmas!

Posted by frank arnstein (Member # 330) on January 01, 2010, 04:09 AM:

Hi Tom & Steve.

The reason you arent getting a gust of air from out the back vents is because thats where the air goes in. It is sucked in by the internal fan & then pumped to the lamphouse through a trap door that opens when enough air pressure builds up. That operates the Automatic fire shutter, preventing film burn at low speed.
Once the air pressure is sufficient to open the gravity operated fire shutter, it makes its way to the lamphouse and emerges at the top throught he vents.
If your projector isn't getting up to correct speed, it won't deliver enough air volume to open the fire shutter trap door wide enough & you will get poor air volume at the lamphouse.
If its working OK, quite a lot of warm air is pumped around the lamp and out the exit grill. Thats where to feel for air flow. Not out the back. Look in down to the globe, and there alongside it you will see the fire shutter activating lever. It should move when you increase the revs above idle speed & it will lift the fire shutter & allow light through the lens.
Let us know what you find.

dogtor

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