I had a concept that i don't know if it would work but hey stranger stuff has happened

This idea is courtesy of myth busters and the "death ray" episode if you all watch myth busters you probably know where i'm going.

The concept is a vacuum/mylar concept.
What i am considering doing is to create a thin frame (metal wire or something of that sort, around the frame of my box slightly infront of the lamp location or perhaps adjacent to it... i would use this to drape the mylar film (98% reflectivity) and leave enough slack to create a bevel. from the rear of the box behind the bevel i would create a low power vacuum (perhaps via a fan or perhaps just make it a sealed vacuum to prevent the mylar from wobling)

This would create a full size reflector over the entire back of the projector, one big solid reflector with a very high reflectivity rating.

The problem as i see it are 2 fold.
1. getting the proper bevel / parabola (the same problem they had in mythbusters but overcame it with some good calculations) and since its a square parabola style reflector...

and the bigger problem

2. The heat, the problem of keeping the heat away from the mylar is my issue, primarily because its very thin (1mm) but i've heard that mylar is very good at heat protection... but the problem is i can't find figures, i don't know what kind of heat mylar actually resists before it discolors or melts...

Sure it could be done. The problem is making the skeleton upon which the mylar goes. A very high degree of precision would be required.

GO FOR IT!!! And report your findings here.

Edit: You're talking about an unsupported reflector here? Just the periphery is held? And you use vacuum to form the reflector?

Edit 2: Another thing - you're starting with something of relatively low plasticity/elasticity so I don't think the mylar would form a compound curve very well without wrinkling.

if i wasnt the worst manufacturer i would have already started lol... perhaps after my PJ is built and working... im already worried enough about getting that together and cleanly built hehe but the idea came to me and i had to get some input around it.

Mythbusters rocks!

P.S. mylar can take more heat than most lcds.It could work just fine.Depends on your manufacturing skills.

If you started with a round ring it would probably be easier to create the parabala shape. If you could get the shape right with a vacuum maybe you could spray something on the back of the milar (like some kind of resin or something) to make the shape stay the way you want it.

Once you've got a round parabala that's keeping it's shape without the vacuum you could cut it into the rectangle shape that would work good in a projector box..

???

I hope you figure this out, just because it's a really neat idea.

Unfortunately, I'm not smart... so I can't help you figure it out.

I'd have to make something that drys slowly... plaster or something that wont drip off and will slowly dry ... and then after thats on the back use the vacume to create the parabola... after tahts done cut it out would be quite interesting to do but as i said im no engineering genius so actually building it to accomplish the vacume would be above my head arggg.

The problem is that the mylar would stretch into a parabola (as we already know from mythbusters) which is a bit useless for us in our projectors because we already have a frensel that collimates our light perfectly.

Has anybody tried to use chrome paint to make a reflector. You could make a reflector out of metal or wood that looks like the pro reflector only bigger and spray it with chrome paint.