What I would like to make

[Dunny]

Well i'm fairly new to projectors but this is what i would like to make


[IMGDEAD]http://img291.echo.cx/img291/6049/projector4wm.jpg[/IMGDEAD]



I plan on gutting my OHP and LCD screen and putting it into a custom box. alot of the plans i see end up makeing a really long projectors.
I'd rather it be tall then it can just stand at the back of the room on it's own and be on axis to the screen.

doing all the cutting and electronics i'm fine with i'm just wondering what distances things should be set apart

how far should the light be from the fresnel, then the lcd a few MM above that, Then i'll measure on the OHP the distance from the fresnel to the lens and rig up some kind of way to focuse it

The OHP i have has the light mounted on the side then hitting a mirror and going up to the fresnell.
If i measure the distance from light to mirror to fresnell add them up and thats the vertical distance i need?


The light is 400w
Its set up kinda like this

[IMGDEAD]http://img143.echo.cx/img143/4401/light2nr.jpg[/IMGDEAD]

whats the deal with the bit infont of the light


Thanks for any help you can give
Dunny

 

[machs_fuel]

distances are determined by the lenses which you will use. you'll need to determine the focal length of your primary lense and your fresnels.

there is a spread sheet calculator on the DIY builders page somewheres.

 

[Guy Grotke]

spacing

Leave at least 20 mm between your fresnel and the LCD. Too close and you will see fresnel rings in the image.

 

[liam545]

in a few weeks after my exams i am going to use all the parts from my gutted ohp with my lcd panel and make a custom box for it too.

i thought about this option too it seems sensible ill keep checking back see if we can bounce ideas off one another,

- first make sure you put that top fan right on the lcd so air is flowing over the top and bottom of it to stop it from melting

- also the focussing mechanism is harder in a vertical pj like this, basically how are we going to get the ohp head unit to move up and down, hmmmm (this is the reason i was going to go for a lumenlab standard instead)

- and as for measuring the distances - set up your lcd on top of the ohp stage and then focuss it onto your wall from the distance you want and measure all the distances there and then!

- bulb to fresnels and protective glass (stage)
- lcd 20mm above that
- lcd to lens

KEEP US POSTED !!

 

[Dunny]

As for setting up the top lens part i was just going to find a way to bolt the current adjustment thingie into the side of it it or make something totaly custom, I don't want it set at a fixed position because i'll prolly be moveing it around the house