Bout time i posted my projector build so here are the specs...

Lamp is a philips 150 w double ended Metal halide lamp, free from the rubbish bin still working too !!
DVD player is an 7 " acoustic solutions model 222 ,30 pds on ebay
front lens is a buhl 11" EFL lens ,5 pds on ebay
cooling fan is from an old computer
im using the battery from the dvd player to run the cooling fan and the mains adapter to run the dvd player


The screen resolution is only 480 x 240 so its not that high but still very watchable from 8-12 feet
projected screen size is 75" diagonal, screen door effect is not really noticeable from over 8 feet away

First ill start with the lamp side of the projector...
as stated the lamp is a philips 150 w double ended Metal halide lamp and
as you can see ive used ceramic tiles to make the heat shield and reflector with..

The tiles are held in place by copper wire

Lamp ballast sits in the wardrobe out of sight and out of the way

I used one of the 3 lens from a ohp triplet (theres 3 separate lens if you take one apart)
and mounted it on a piece of wire shaped to act as a spring to hold the lens in place

as you can see i have used this as my condensor lens, it gives me around 20% more brightness,
It just hangs from the top tile

Shape of condensor lens, curve facing forward

Next is the mounting for the lighting, i used a 3 point adjustable mount i
got this idea from my telescope making days,basically just means you can
adjust the light center be a centimeter in any direction up down and sideways

Next is just an over view of the lighting box,
as you can see ive tiled the front and sides of the box and ive
cut a square hole in the tile large enough to let the light pass onto the screen

Theres a peice of glass placed between the tile and the ply to stop the heat

.

Ok so now to the Fresnel's
The Fresnel's are from an ohp,you will find the single fresnel lens on an ohp is in fact 2 samwiched together
so you can split them into 2 separate lens with 2 difrent focal lengths
i have split them and cut them down to size
The fresnel's have 2 different focal lengths one is approximately 24cm the
other is 40cm
the 40cm is placed facing the rear of the projector and the 24cm facing the front

this pic is the rear facing fresnel note the smooth side faces out
note also the two cuts on the top corners

when mounting the screen its self dont forget to mount it upside down
so when your looking at the screen from the front of the projector this is what you will see

Front facing side of lcd screen mounting with the 24cm fresnel smooth side facing front of projector

So the complete screen mounting with fresnels
note the rear fresnel sits flush with the plywood and the front fresnel has a gap of 20 mm

the front lens is tight fitted trough a hole cut in the front of the projector box,
to focus just move in and out, you can use a triplet fron an ohp but you will get
a smaller screen with this setup approximately 55 cm compared to this 75 cm..
My projector is around 12 feet from the wall

the lens its self is 12cm long and 10cm diameter

The dvd player is mounted on 2 rails its just sitting on them and
not fixed, the power supply is supplied by the dvd players adapter
and the sound by a pair of desk top computer speakers

last of all is the lid, it just sits on top projector and has one cooling hole 8cm in diameter
and the cooling fan is 8cm as well, the cooling duct came from a old p2 computer and its
powered by the dvd players battery supply

The positioning of the cooling hole as you can see by the pics cools both the light box and the
area in front of the light box
this is an exhaust fan and the inlet for the cooling air is the three slits on the back panel of the projector

.

Now the all important screen pics ....
bare in mind the low resolution and the fact it was daytime and the pics are
from a cell phone so rather grainy..

Well there you have it my budget build projector
in a fully dark room the images are brighter and well saturated but the bright daylight secnes
can be a bit washed out, other than that and bearing in mind the tiny resolution this is a great budget
projector you can knock up for yourself in a day or two...

just a note about the fresnels..if you use the fresnel from an ohp you can split the single one into 2 separate fresnels,
one should be 24 cm focal length and the other 40 cm approximately, cutting them to size was done with an angle grinder
with a cutting wheel, you dont need to cut right trough the lens just make a score line bout 1/3 of the way trough and they
will snap off along the score line,seperate them first of course !!

Nice work, trademe.

Nicely done, congrats.

sim

that was a very clever idea for your lamp reflector i was thinking of mounting my balast on a ceramic tile to keep the heat away from the wooden floor of the pj.

you did a good job with that small screen . best one ive seen yet

Looks good, I'd be interested to know how much light spillage you have around the triplet with that 40cm collimator fresnel.

I'd expect even better results with a 24cm collimator fresnel, given the rest of those dimensions, but if there's no excess of light around the triplet, then it's all good.

I like your precondenser lens mount.