Home made projector!

[BobRoss]

Have you considered using stepper motors to turn some sort of threaded stock with mounts welded to nuts on the threaded stock? Something like this:
http://www.microkinetics.com/graphics/ballscr.jpg
There are lots of cheap stepper motor controllers that are pretty cheap and easy to figure out and obviously you have a pretty keen knack at figuring things out...lol

You could use hand cranks also or instead if you wanted.

[spanielgita]

good news again, i have my camera cable back so i will be taking pictures at some point today and posting them.

also, more importantly, the german website is in stock of the items i need;

a 310mm fresne
a condenser lense
the reflector

so i have put an order in for these items with insured delivery. there is however a problem. i cant tell if i have actually paid for it yet!? i dont think i have seeing as there is nothing on my paypal account saying that i have! but i cant understand the german site. i have what looks like a receipt... but i still dont know if the payment has gone through and if not, how do i actually pay for this!?!

chernobyl i am (yet again) in need of your help! can i give you my email or do you use msn? would appreciate some advice on this one!

[ChurchSubgenius]

Originally Posted by BobRoss

Have you considered using stepper motors to turn some sort of threaded stock with mounts welded to nuts on the threaded stock? Something like this:
http://www.microkinetics.com/graphics/ballscr.jpg
There are lots of cheap stepper motor controllers that are pretty cheap and easy to figure out and obviously you have a pretty keen knack at figuring things out...lol

You could use hand cranks also or instead if you wanted.

Hmmm, is this a non-sequitur or a reply to I post I didn't see?

[Chernobyl]

Originally Posted by BobRoss

Have you considered using stepper motors to turn some sort of threaded stock with mounts welded to nuts on the threaded stock? Something like this:
http://www.microkinetics.com/graphics/ballscr.jpg
There are lots of cheap stepper motor controllers that are pretty cheap and easy to figure out and obviously you have a pretty keen knack at figuring things out...lol

You could use hand cranks also or instead if you wanted.

Thanks for the idea, it may come in handy for manual adjustments
I wont be using motors as once adjustments are completed, the job is done. Cost and complexity are of concern.

I'll be making 3 different assemblies inside the main projector box:
1) the rear reflector, light and condensor lense
2) mounts for the lower fresnel and glass,
3) mounts for the LCD and maybe the top fresnel.

Each area will have its own cooling channels.
I'm thinking of making a removable wooden shroud to sit on top which will contain the top fresnel, the triplet lense & mirror and the LCD's upper cooling .

The master plan is to allow adjustment of each assembly and also allow adjustments of the rear reflector, bulb and condensor on their own assembly.
I want to make screwdriver adjustment points or similar which can be accessed either externally or through port holes in the projector case while it is running.

(Hi BobRoss, this suggestion made was in reference to my making adjustable mounts)

[Chernobyl]

Originally Posted by spanielgita

good news again, i have my camera cable back so i will be taking pictures at some point today and posting them.

also, more importantly, the german website is in stock of the items i need;

a 310mm fresne
a condenser lense
the reflector

so i have put an order in for these items with insured delivery. there is however a problem. i cant tell if i have actually paid for it yet!? i dont think i have seeing as there is nothing on my paypal account saying that i have! but i cant understand the german site. i have what looks like a receipt... but i still dont know if the payment has gone through and if not, how do i actually pay for this!?!

chernobyl i am (yet again) in need of your help! can i give you my email or do you use msn? would appreciate some advice on this one!

Hi Dan
Glad he has stock at last!

I can PM you with the place to make payment to if he doesnt get back to you but I understand that isnt really an acceptable method as you have no real idea if I am trustworthy.
Send him an email and ask how to pay (mention Paypal). I did the same when I bought my bulb from him too
Its a drawn out process ordering from him but his goods are cheap and damn good quality (when he has them lol).

If you have trouble setting up the lenses, I can measure my setup for you.
This may help a little but ultimately you will need to adjust everything for the size of your bulb which looks bigger than mine.

Looking forward to seeing your result

[spanielgita]

righto,
in that case i will wait a day and see if he emails me about the payment. if not i will send him an email.

i think i have a solution to the uv problem also. there is a really thick piece of glass in my projector originally. i think it must have been there to block out uv. is there any way i can test wether or not the uv is getting through?

really glad i got the fresnel from that german site, was going to order that other one off ebay but gave his site a last check and he was in stock! he also had the reflector back in so i got that too! good day!

also - it would be helpfull for you to explain how you measured the distances between individual items in your setup, as i think mine will be a little different.

also i was thinking - do you think that the bulb being put in diagonally will have a big difference? i can't see how it would becuase the bulb is still in the centre but it might. any ideas?

thanks Dan

[Chernobyl]

Yes the thick piece of glass is your UV filter, brilliant
I hope that it will be good enough for this bulb.
You can check for UV with UV flourescent dyes/paints.
I should have done this myself lol (slaps forehead).
The result you will get by comparing direct light to that coming through the filter should give you some idea of how effective the filter is but I have no way of knowing if you have too much.

As always, when working with an open bulb live, hide at least your face behind a plastic screen and wear very good UV resistant glasses.
Try to NEVER look directly at the light source.
These bulbs can explode in a big way if there is a flaw or heat spot.

I would say that fitting the bulb diagonally will kill the polarisation.
NAAAAA, just kidding, it wont make any difference
I hope it fits inside so you can adjust the height easily.

I'll try my best to explain how to adjust the lense/bulb/reflector positions.
1) Try to mount all 3 on one platform so that the whole lot can be moved further/closer to the fresnel.
2) Find a suitable mount for the rear reflector on the platform and make that permanent.
3) holding your finger above the reflector, you will see an inverted image of your finger. Looking through one eye, move your finger towards/away from the reflector until the image you see is exactly the same size/width as your finger. This is the focal point and where the light bulb core needs to be placed. You will need to try small adjustments to get the best position which is a nightmare if you need to turn it off to make them!
4) Mount the condensor lense as close as possible to the bulb while allowing a small air gap. If you do have it this close I highly recommend having a dedicated 80mm fan inside the OHP blowing on the bulb/lense to cool them. Dont worry about temp differences across the bulb, these bulbs cope very well with this method as they arent as hot as Halogen bulbs. This will also extend the life of the bulb and slow down any dimming /colour shift.

If you are unable to mount the bulb core at focal point of the reflector, you have 3 choices
1) make the best of it, perhaps it will still be superb?
2) change the rear reflector for something else, maybe the IKEA napkin holder will do better?
3) change the bulb to a HQI type

Once you have made the complete platform with all 3 mounted on it, you may notice that the corners of the screen are excessively dark or miscoloured.
Moving the assembly further/closer to the Fresnel will fix this.
I hope you have enough distance inside the OHP to get far enough away as this is likely to be your main issue.
If really stuck, mount the Fresnel on top of the OHP glass with the LCD sat on top of it.
I am doing this temporarily. If you look hard for it, you can see the fresnel rings on the projected image but they are so hard to see, it doesnt bother me so I'm leaving it like this until I make the HD projector.

Worthy of noting, once the fresnels are split, they do warp a bit!
The only thing I can think of to prevent this is to mount them on/under glass, glued or locked in place.
In the HD projector, I am mounting the lower fresnel on a sheet of glass which will also serve as a cooling section boundary/separator.
I may have to do the same with the upper fresnel so will be looking for a very thin/strong piece of glass.

I'd better post this before I write up the whole project here

edit:
split fresnels also pick up dirt in the grooves very easily.
This could be a major annoyance, I havent fallen foul of it yet though.
Only ever clean the fresnel grooves with compressed air.
Mounting the grooved side against glass and sealing the edges is the most surefire method of preventing this.

[spanielgita]

Originally Posted by Chernobyl

Yes the thick piece of glass is your UV filter, brilliant
I hope that it will be good enough for this bulb.
You can check for UV with UV flourescent dyes/paints.
I should have done this myself lol (slaps forehead).
The result you will get by comparing direct light to that coming through the filter should give you some idea of how effective the filter is but I have no way of knowing if you have too much.

yeh i think i might give this one a go if i can get the paint, but to be honest im just glad to have any sort of uv filtration at all.

Originally Posted by chernobyl

I would say that fitting the bulb diagonally will kill the polarisation.
NAAAAA, just kidding, it wont make any difference
I hope it fits inside so you can adjust the height easily.

OMG i tottaly thought for a second that it was going to be a diasaster. you got me mate!

thanks for the info about the lense spacing etc. this should come in mighty handy when i am fitting my stuff

Originally Posted by chernobyl

If you are unable to mount the bulb core at focal point of the reflector, you have 3 choices
1) make the best of it, perhaps it will still be superb?
2) change the rear reflector for something else, maybe the IKEA napkin holder will do better?
3) change the bulb to a HQI type

i am oredering the reflector from the german shop. planning on using it in conjuction with the ikea napkin reflector. this all depends on wether i can source a dremel drill though. which i think i can.

i didnt know that the fresnels warped when split i do have a large peice of spare glass so i can at least use this for one of them!

right, on to picture posting! i have millions. finally got round to putting them on my pc.

[spanielgita]

the lid took alot of time and effort - mainly because i was using a hand held hacksaw!!! but i got there in the end(with a bit of pateince) just kept hacking away. all it needs now is a bit of sanding/filing. now the whole projector screen will fit over the lid allowing the whole screen to be projected(thats the plan anyway).

[spanielgita]

#

you can see the amount of metal that has been cutaway to make room for the bigger fresnel and screen.



250watt metal halide at its biggest i think - this thing is HUGE but it will fit and runs way cool. nice colour coming off it also - esp notice that when compared to a desk lamp colour.



haha - doesnt the old school lamp look so tiny next to the beasting halide!



not the best pic, but a sneaky peak at the unfinished "ET cover". this is made from blackout material - same as my pj screen!



this is the mounting system for the orginal bulb, reflector and uv glass. i will modify it to accomodate the new stuff. might prove quite difficult with a diagonal lamp of course.

[spanielgita]

oooh almost forgot to mention!

i was browsing hack-a-day and found a hack to make an xbox remote into a fully programmable pc remote controller! the hack uses a really straightforward system based on c++. you can pick up these remotes for under £10 on ebay! seems like a worthy addition to the pj project.

heres the link http://www.hackaday.com/entry/1234000640073739/

EDIT: after following that link click on the "READ" link on hackaday to get to the hacker's blog.

[Chernobyl]

Thanks for the progress report, it does look like a fair bit of work!

tbh I think using 2 reflectors together (one cut open to fit the other inside - in case you missed that bit readers) is going to be hard work and isnt likely to give an even result. I'd love to be proved wrong though and hope it goes well
I have a feeling that you will get a decent result from the reflector you are buying.

The space you have for the LCD now is super, you shouldnt need to make any adjustments to the screens width. Nicely done.

Hmm, I have toyed with getting a remote control for the PC for some time and the XBox remote looks just the ticket. Thanks for the link, I'll have to do that some time.

Good luck getting the light/lense etc assembly fitted.
I'll be looking forward to what happens next.

[spanielgita]

finally paid for the goods today via paypal - so hopefully he will send them out soon so i can get this thing built!! i think i may need some advice on how to wire up evrything so that it works from the projector and i dont know how much power i can put through my fans etc, but i suppose i can leave this till later.

Dan

[Chernobyl]

top!

Sure I'll help you wire it up.
Theres a wiring diagram on the website
http://62.75.177.102/shop2/index.php...oid=13&skat=25
Click the picture.

Your Fan in the OHP should already be wired in and will automatically work if you use the same wiring.
The transformer will be fed by a blue wire and another wire which comes from the power switch and fuse. If you use those wires as the inputs to your new transformer, the power switch and fan will work just as before.

If that doesnt make sense or its a bit different lemme know.


I've been waiting for a few days for responses from The LCD controller and Sharp Electronics.
I called the LCD controller mfr (Digitalview) and the guy on the phone said the representative was in. He came back and said he wasnt in and can I email him.
I did so on the 13th (1 week ago) and he hasnt responded.
This is unprofessional so I'm looking at other companies controllers now.
If they respond I'll consider using them but if not, it would seem they dont want to deal with the smaller guy.
Its a pity for Digitalview as I'm about to post some competitors I wouldnt have found otherwise

these look very good so I'm going to get in touch with each of them:
http://www.horizontechnology.com/controller_boards.php
http://uk.kontron.com/index.php?id=2...&productid=653
http://www.smartm.com/product/product.cfm?productID=61


Its been a real struggle to get hold of anybody in Sharp to talk about their LCD panels. I want to know if the LQ154M1LW02 and LQ154M1LW12 panels are restricted to 6 bits per colour (256,000 colours) or of they can do 8 bits (16.7 million colours).
I have phoned a number of places within Sharp and received a few calls back.
They have all been very helpful but dont seem to know who to talk to.
The last guy emailed someone within Sharp and cc'd me 2 days ago. He hasnt replied yet.


Onto the game...
I had a play with the top fresnel lense to perform keystone correction so I can put the projector nearer the floor.
The shroud has been removed so the top fresnel can be repositioned.

With the OHP sat 8cm off the floor (LCD height 34.5cm, centre of mirror height is 80cm) using the original setup, the top of the screen is much wider than the bottom.
Raising the bottom of the fresnel makes the bottom of the picture bigger on screen.
The fresnel rests 13mm above the LCD and ihas been inclined 15 to 20 degrees at the bottom (raised 3cm) - see photo.
The picture is straight but the whole screen has to be very slightly out of focus to get the focus even.
The fresnel also flexes with gravity and produces a very slight curve at the top and edges of the picture. For the HD project the fresnel edges will be kept flat by mounting it in a frame.

I am going to raise the OHP slightly to find the optimal height to get acceptable focus.
I am worried that this technique wont be practical for the High Definition LCD as I may need all the sharpness I can get!
Theres only one way to find out

[Chernobyl]

Oh yes,
Dan this may be of interest as you will be playing with your bulb height.

I have removed the lower fresnel from the OHP glass and placed it back inside the OHP to get rid of the faint fresnel rings on the screen.
After splitting the fresnel I found that he bottom fresnel needs to be a bit further away from the light. Indeed it is too close now and the corners of the projected picture too dark.

The bulb height is adjustable on this OHP so I moved it as low as it will go and the corners get much brighter but still not enough.
So I took the glass off the ohp and placed it underneath the fresnel inside the OHP to raise the fresnel slightly.
The final result is a very clear picture (no fresnel rings) and even brighter corners but still not enough brightness.

To get the fresnels distance from the condensor lense correct in this OHP, I will need to either
1) bend the bulb mounting frame so it sits lower or remove the adjustable frame completely, mounting the bulb assembly on the OHP floor.
2) cut away the plastic underneath the OHP lid to allow the fresnel to get closer to the LCD
3) place the glass back on top of the OHP and put the fresnel on it again. Make a light sealed mount for the LCD to hold it a small distance above the fresnel.

Try the bulb mounted as low as possible first and raise it to test.
If you can somehow make an adjustable mount it will help you a lot now and later as you try things out.
Its hard to see the difference height makes if the light isnt switched on and its very hard to find the optimal position unless you can see the difference as it happens.
Please dont us a method of adjusting the height that needs your hand inside the OHP while it is on.

This may help to get started - a quick and dirty method of finding the approx right height:
Mount the light/lense any way you wish.
Put the fresnel on top of the OHP glass with the LCD sat on top.
Get a friend ready on the OHPs focus control and raise the fresnel/lcd assembly until you get the corners are at their brightest.
Get your friend to record the height of the fresnel from the floor and later find the height from the condensor lense

(when using a condensor lense above the bulb, the distance that counts is that between the condensor lense and the lower fresnel)

[spanielgita]

thats a pitty that they dont make more of an effort to get back to you! if only they knew what potential business they could gain if they were more professional. seems very stupid to me anyway.

Anybody who asks me about my projector and how to make one will be told about this forum, about the amazing amount of in-depth, correct and accurate advice you so readily give. these people will read your posts about good suppliers etc etc. Whoever said that individuals dont count eh.

yeh i think it should be fairly straightforward to wire it up i would just like your advice also when i am doing it.

There is however VERY bad news on my side. There is going to be a monumental delay!!! the German supplier, the only place(as you know) to supply all the parts i need, have decided to go on holiday until - wait for it - the 9th of september!!!

i am really gutted, i thought it would be a case of the end of the week not a month and a half!!!! really isnt good

i even made the payment and THEN i was told that they were on holiday, i dont understand how the holiday is for such a long time! i wish they could just send out the things that i have paid for. i was really stretching my budget just to get these parts and now they aint coming for ages, its a kick in the teeth but what can you do eh?

[Chernobyl]

Whoa, sorry about your dilemma.
Chaz had pretty much the same thing happen to him a while back!
I suppose we should be grateful he runs a site we like but thats harsh.

[spanielgita]

yeh it tottaly puts a HUGE downer on things for me but i will get everything else done, like the remote and finer work around the lid, the wiring of the lighting, the covering and perhaps even making it look a bit better in the outside who knows - i do have alot of time to kill until those essential parts arrive anyway. i sent them an email expressing my dismay but i dont think it will affect things in anyway.

[Chernobyl]

thats a good idea .
Did you read the second post I made above?
You might like to tackle the adjustable light mount while waiting.

[spanielgita]

yes that does seem like a good idea - i was thinking if i get a dremel of some sort i might cut away at the side of the projector which would allow me to setup a system to adjust the hieght of the light and position the bulb across the ohp horizontally