Step 6: Measurements
This step is very important, now u have to try to get the LED (with it's heatsink), the condensor lens, the fresnel lens, the LCD and the slide projector lens, in line. Pay good atention to the center of everything. and play with the distances between them until you happy with the output.
Once u have the distances 1, 2, 3 and 4 u can calculate the size of the box you'll be looking for.
To calculate the distance 4, try to project the screen size you want. And if u have enuf space it'll be nice if you can retract the lens all the way in without touching the LCD.
Note: Don't worry if u don't have the LCD connected and working, u don't need it working for this step as u will be able to see the dots of the screen in the projected image. Just make sure when fiting the LCD, that the image it shown upsidedown, so the projected image will be straight. what i usualy do is write on the LCD a word (like "hello") when u have it working. that way you make sure the LCD is in the right position without having to connect it all the time to make sure it's right. Just write with something u can erase later.
Note 2: If you're taking a bit of time to do this, have the fan working to avoid overheating the LED.