mkdxdx
Disclaimer: there will be a rough part list and BOM provided, but I do not guarantee everything will be available or everything will fit exactly like I'm describing it. Some parts are old, some are new and everything went through several fit-together iterations and by providing STEP files - I encourage you to do the same.
Just in case, the basic principle of operation is as follows:
A powerful (point) light source shines through a collimator lens that makes light beams somewhat perpendicular to it's plane. These beams pass through a picture source (anything transparent will do). And then colored (and severely attenuated!) beams pass through a concentrator lens, to be thrown on the wall with the help of the projector lens.
And so, what is left is to fit necessary components securely, let them breathe - because it all either generates or absorbs noticeable amount of heat, bring in a suitable power source and make it all work and also put it all together in such a way that it won't fall apart after being tipped over.
Both collimator and concentrator lens are PMMA fresnels can be bought as a kit for DIY projectors (mine have 120mm and 185mm focal lengths respective and are suited for 5.8" picture placed between them - or else there will be vignetting), while projection (210mm focal length, adjustable holder) lens is bought separately.
The screen part is taken from a broken monitor - mine got broken backlight, but since panel was okay - I just got it out of it's case, removed diffusers (but do not remove polarizer films - those are glued on, you will feel it - only remove the ones that just sort of sit in the case) and arranged it in the structure in such a way that the flat flex cable is not under the stress when it is connected to it's input board.
You're going to need a powerful LED for the light source, and ideally - it also needs a narrow angle lens that not only somewhat compensates LED's squareness, but also gathers more light towards the collimator. This project uses 100W 34V LED - so it also needs an active cooling stack consisting of heatsink, fan, lens and all the required brackets and fasteners to put hold it all together. Obviously, the heatsink must have thermal paste between LED and it's heat transfer area.
The lot above says "cool white" but it should not matter that much as you can probably compensate that in picture settings. For some reason seller recommends cool white for DIY projectors.
Mind the LED footprint so it fits on your cooling stack!
LED needs a constant current driver, so anything for LED's rating will do - i'm driving this 100W led with 30W driver because 100W driver made it too hot for heatsink to cool it's core. It also need minimum forward voltage of 28V to start shining - so pay attention to that. I'm not using dimmable driver so I won't be able to adjust brightness naturally, but as a bonus - driver only needs mains input to do it's job.
You are also going to need a separate PSU for the rest of the stuff - to power the screen, the LED fan and so on. The power area carrier is made for these cheese case PSUs with 85x35x60mm dimensions.
Some parts also can accomodate LM2596HVS step down converter to power additional elements.
Additionally - there is a carrier case for RPi3 to make this projector more into like an autonomous media center. This one will not win perfomance competition either, but I've had one lying around, so why not.
The main structure elements are these chrome plated Ф16mm hollow steel pipes. You'll need at least 4x500mm to hold lens and screen assemblies, 4x200mm for an "upright" position and also 4x200mm as a horizontal flip-tilt frame - but not going to say it's the best solution - I've just had those lying around after I've torn down my workbench shelves.
You are also going to need a lot of fasteners. Mostly countersunk M3 of different lengths with nuts, but horizontal flip assembly and lens insert need M4 countersunk bolts, and hinge blocking mechanism will need M5 bolt with...
STEP archive will include this and previous additions.