Fan 'splash guards' ??

[norty303]

Ok, I'd never really thought about this before but it makes perfect sense.

I've opened up 2 of my projectors this week to do some maintenance, and on both of them, there was an amount of fog fluid on the underside of the lid, just in front of the where the fans are. I can only surmise that fine haze gets past the filter (quite dense ones in my case), and gets picked up by the spinning fan, and flung out in an arc onto whatever is just inside the fan entrance (in my case a breakout board, scanner amp and safety board)

I'm thinking that a secondary, more open filter on the insode of the fan would catch a lot of this fling.

Has anyone else noticed this, and have you done anything about it?

[andy_con]

Yes I've noticed, so I redesigned the projector in such a way that it does not matter.

Move the fans out the optical deck and problem solved

[The_Doctor]

If you can't avoid the fan moving air through a chamber where the optics or electronics are, any chance you can make the fan pull air through, instead of push? Then put a good filter on a passive intake on the other side.. This works wonders for dust too, and keeps the fan cleaner.

The fluid is moderately volatile so a gentle heating from a strategically placed power resistor might help clear it faster than it can gather in local accumulations of the stuff. This volatility is why you'll always have it somewhere. A filter would have to be gas-tight to stop it, so the question is can you get rid of it once it arrives..

[Galvonaut]

Could the fluid come out of suspension in the air due to pressure change? I'm wondering if an input with a venuri and a collection tube before the fan would force the fluid out pre-fan?

Keith

[norty303]

Move the fans out the optical deck and problem solved

Is the rest of the equipment in the projector not also at risk then? As I said, it is electrical equipment in the firing line, and having seen what years of fog fluid build up inside moving heads and scans does, having it coating that stuff is fairly undesirable.


Doc, I like to use positive pressure in my projectors, otherwise you end up just pulling in air through joins that are unfiltered.

Keith, I think a simple square extension on the inside of the fans would actually catch the majority of the fling, and then you can just clean it periodically. Effectively I'm just providing a barrier on which to catch the residue, that isn't something that shouldn't have fog fluid on it! I accept its going to happen, so its about controlling it.

[andy_con]

again move them out the way, its all about the right design ;-)

my projectors are fan cooled by the fans arent in the optical deck or the electronics deck. they are sealed away

[laserlackey]

This may sound hokey, but placing the fans on the outside and pushing air into the filter instead of pulling it through may work?

[norty303]

again move them out the way, its all about the right design

Yes, I'm sure, and fairly easy when working on a new projector.

This may sound hokey, but placing the fans on the outside and pushing air into the filter instead of pulling it through may work?

Or it may make the projector look aesthetically ridiculous (I do have to hire these things out you know )and not fit in the flight case anymore...

But otherwise yes, all fantastic suggestions!

[laserlackey]

I think this may be close to what you're looking for. It could be adjusted for whichever size fan you're using. I have a 3D printer if you're interested in trying them out

[norty303]

Yep, just like that but full circle

Good find BTW