Ok, I've been lurking here for what feels like years. I built my first projector 4 years ago or so, with an ohp, and a sharp panel. Worked brilliantly, then i found this forum. my lcd died and i forgot about it for awhile. Suddenly it seems people started building thir projectors outta little screens, and that appealed to me. So last week I started ordering parts and I have nearly everything i need except my projection lense. Still trying to decide what i'm going to use.
But without further ado here's the Part/Price list so far.
From my drop ship company
5.65 inch lcd Active matrix TFT(starvision something or other.) $69
From Surplus Shed
SKU: L3282 6-SIDED LARGE FRONT SURFACE MIRROR $5
SKU: L3312 FRONT SURFACE MIRROR, 5" LONG BY 4-1/4" WIDE $4
SKU: L3101 COLD MIRROR, 4.75" DIAMETER $5
SKU: L2030 GLASS ASPHERIC LENS $6
From Home Depot
500 Watt Halogen light (used to light a yard and that kinda thing) $15
From my parts pile
Mid tower ATX Case. Free.
Guestimation for Projection lense, $25-35
Grand total: $104 ($109 or so with shipping)
So with any luck this thing's gonna only cost me around $200 or so. Any ideas on a good Projection lense from surplus shed, would help. I'm thinking of a decent lense with focal length of around 80-100 mm (dont want the pj to have to throw an image 30 ft away to get a biggish screen, ya dig). I hope to start building this this weekend. Should be fun, mucking around with light paths trying to hammer out the perfect configuration. Build pics to follow as I have them.
Wish me luck.
But without further ado here's the Part/Price list so far.
From my drop ship company
5.65 inch lcd Active matrix TFT(starvision something or other.) $69
From Surplus Shed
SKU: L3282 6-SIDED LARGE FRONT SURFACE MIRROR $5
SKU: L3312 FRONT SURFACE MIRROR, 5" LONG BY 4-1/4" WIDE $4
SKU: L3101 COLD MIRROR, 4.75" DIAMETER $5
SKU: L2030 GLASS ASPHERIC LENS $6
From Home Depot
500 Watt Halogen light (used to light a yard and that kinda thing) $15
From my parts pile
Mid tower ATX Case. Free.
Guestimation for Projection lense, $25-35
Grand total: $104 ($109 or so with shipping)
So with any luck this thing's gonna only cost me around $200 or so. Any ideas on a good Projection lense from surplus shed, would help. I'm thinking of a decent lense with focal length of around 80-100 mm (dont want the pj to have to throw an image 30 ft away to get a biggish screen, ya dig). I hope to start building this this weekend. Should be fun, mucking around with light paths trying to hammer out the perfect configuration. Build pics to follow as I have them.
Wish me luck.
four suggestions
1. You might want the glass under the lower fresnel to support it. Thin acrylic fresnels tend to sag if unsupported.
2. You need UV filtering, or you will damage your LCD's color filters. You can get a UV filter sheet cheap at many of the DIY projector online stores, or change the safety glass to Lexan XL10 from Home Depot. Cheaper than glass and it has a very good UV filter.
3. If you use a slide projector lens, then your LCD better be the size of a slide (2" by 2"). Otherwise you will get an enormous image with very little throw distance. I don't think there is room between a slide and slide projector lens for a mirror.
4. The whole point of a condensor lens is to capture as much light as you can from the lamp. You do that by putting the condensor lens as close to the lamp as possible. It would also capture more light with a spherical reflector behind the lamp.
1. You might want the glass under the lower fresnel to support it. Thin acrylic fresnels tend to sag if unsupported.
2. You need UV filtering, or you will damage your LCD's color filters. You can get a UV filter sheet cheap at many of the DIY projector online stores, or change the safety glass to Lexan XL10 from Home Depot. Cheaper than glass and it has a very good UV filter.
3. If you use a slide projector lens, then your LCD better be the size of a slide (2" by 2"). Otherwise you will get an enormous image with very little throw distance. I don't think there is room between a slide and slide projector lens for a mirror.
4. The whole point of a condensor lens is to capture as much light as you can from the lamp. You do that by putting the condensor lens as close to the lamp as possible. It would also capture more light with a spherical reflector behind the lamp.
500 Watt halogen flood
If this is the light you are planning on using, it might not work very well as the light emits light the entire length of the tube, and although it emits a lot of light, not much of it will be usefull. You really need to find something thats a point source. However, if you do use one of these lights, they usually come with glass that has a UV filter in it. Or at least the worklamp versions do. See below
500W worklight
If this is the light you are planning on using, it might not work very well as the light emits light the entire length of the tube, and although it emits a lot of light, not much of it will be usefull. You really need to find something thats a point source. However, if you do use one of these lights, they usually come with glass that has a UV filter in it. Or at least the worklamp versions do. See below
500W worklight
i have made a projector with a 500w shop light like you are talking about and 500w is way to hot for the lcd to handel even with the uv filter and lots of fans. i then went down to a 300w halagon blub and solved the heat problem with a blower on the blub and a fan sucking on the other side but the problem was even with a reflector and a condenser lens i light was not much beter then the 50w halagon with the build in reflector and uv glass on it which ran really cool, because with the smalled 50w halagon bulb it was a small point where as the 500 or the 300 was a long tube that had no real center to center the light. If i was you i would not waste my time with the flood light halagon bulbs. if you need to go cheap try the 12v 75w halagon bulbs or you could try a bulb from a slide projector many of them are 300w or even 500w but have a true focal center. the ony down side it how long these bulb last somewhere between 25 to 50 hours.
funny thing...
... after i posted that image, i went out to run some errands and stopped at "bed,bath and beyond" and picked up a mirror finish stainless ladle for use as a reflector.
Also, I should've mentioned that it was rough diagram of the setup. very little is to scale and the condenser would be very close to the halogen.
Moose: thanks for the mention of the built in uv filter. It may save me a trip to Home depot. I'd planned on using the saftey glass as a uv filter, considering it is the same kind of glass they use in cars, and has excellent uv filtering properties. Though I may pick up some lexan just to be on the safe side.
Guy: The slide projector lense I dont think would be an issue. it has plenty of throw distance, and there is a lot of space between the slide and the lense. I'm figureing that the second fresnel will make the light converge. and it it converges enough it will be much brighter and would project just fine. I've been looking at the fujinon projection lense and others at surplus shed, and i cant really see using such a large lense. BTw, your right, i will put the glass, or lexan , below the fresnel. The fresnel i'm going to use is going to be chopped down a bit. It's from a 3m OHP I used as my first projector.
So I think i got all the bases covered.
Closer condenser: check
chrome sherical reflector: check
IR Blocking: check
UV blocking: check
also not in the picture was the fans. i'm going to use 2 PC power supply fans on either end of the halogen.
The only thing i'm wondering about now is the cold mirror will let the ir pass through, that ir however is going to cause heat to build up somewhere else in the case. I'm not digging the idea of cutting another hole for another fan to vent that heat..... Any ideas on that one. considering this is going into a metal pc case and metal transmits heat well, this could be an issue.
Hmm.... now i'm wishing i bought that giant peltier i found on ebay last week.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=294&item=5747294610&rd=1
And just to point out, the halogen is a stand in for a metal hallide. This is proof of concept if it works, it'll end up being replaced by a 400 watt hqi.
Last question, anyone know the particulars of the lexan at home depot? brand that kinda thing.
... after i posted that image, i went out to run some errands and stopped at "bed,bath and beyond" and picked up a mirror finish stainless ladle for use as a reflector.
Also, I should've mentioned that it was rough diagram of the setup. very little is to scale and the condenser would be very close to the halogen.
Moose: thanks for the mention of the built in uv filter. It may save me a trip to Home depot. I'd planned on using the saftey glass as a uv filter, considering it is the same kind of glass they use in cars, and has excellent uv filtering properties. Though I may pick up some lexan just to be on the safe side.
Guy: The slide projector lense I dont think would be an issue. it has plenty of throw distance, and there is a lot of space between the slide and the lense. I'm figureing that the second fresnel will make the light converge. and it it converges enough it will be much brighter and would project just fine. I've been looking at the fujinon projection lense and others at surplus shed, and i cant really see using such a large lense. BTw, your right, i will put the glass, or lexan , below the fresnel. The fresnel i'm going to use is going to be chopped down a bit. It's from a 3m OHP I used as my first projector.
So I think i got all the bases covered.
Closer condenser: check
chrome sherical reflector: check
IR Blocking: check
UV blocking: check
also not in the picture was the fans. i'm going to use 2 PC power supply fans on either end of the halogen.
The only thing i'm wondering about now is the cold mirror will let the ir pass through, that ir however is going to cause heat to build up somewhere else in the case. I'm not digging the idea of cutting another hole for another fan to vent that heat..... Any ideas on that one. considering this is going into a metal pc case and metal transmits heat well, this could be an issue.
Hmm.... now i'm wishing i bought that giant peltier i found on ebay last week.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=294&item=5747294610&rd=1
And just to point out, the halogen is a stand in for a metal hallide. This is proof of concept if it works, it'll end up being replaced by a 400 watt hqi.
Last question, anyone know the particulars of the lexan at home depot? brand that kinda thing.
on another note...
I have 2 identical slide projectors, one being cannibalized for this projector, the other is going to become the home of a 1.5 inch lcd from a tv. i've heard lotsa talk about these little tv based pj's but no images. any ideas?
I have 2 identical slide projectors, one being cannibalized for this projector, the other is going to become the home of a 1.5 inch lcd from a tv. i've heard lotsa talk about these little tv based pj's but no images. any ideas?
lexan
All the Home Depot's around here stock Lexan XL10, which is 0.093" thick very transparent window glass replacement with a UV blocking coat on one side. They have various precut sizes for <$10, so it is very cheap and accessible. Lexan alone (just like acrylic) will do a pretty good job of absorbing UV, but it will turn yellow over time from damage to the polymer strands. That's why they add the UV blocker: To protect the lexan resin. Make sure you install it with the UV blocker toward the lamp!
Some people claim to be able to score it with a razor knife and then snap it like glass. Never worked for me. I tried to snap it with all my weight, and it just broke the rig I had holding it down. Very tough material! It is sold for replacing glass in security windows, since you can beat it with a hammer and barely dent it. Cuts beautifully with a hacksaw or a metal-cutting blade in a power jigsaw. Doesn't crack like acrylic.
While you are at Home Depot, look at their other halogen bulbs. They have a 250 Watt wide pin capsule bulb with a pretty short filament. The 100 Watt wide pin capsule bulb filament is less than 1" long, and the bulbs are small enough that you could put three of them together in a triangular stack. But that would be about $20 total for a lamp rated for only 2000 hours.
All the Home Depot's around here stock Lexan XL10, which is 0.093" thick very transparent window glass replacement with a UV blocking coat on one side. They have various precut sizes for <$10, so it is very cheap and accessible. Lexan alone (just like acrylic) will do a pretty good job of absorbing UV, but it will turn yellow over time from damage to the polymer strands. That's why they add the UV blocker: To protect the lexan resin. Make sure you install it with the UV blocker toward the lamp!
Some people claim to be able to score it with a razor knife and then snap it like glass. Never worked for me. I tried to snap it with all my weight, and it just broke the rig I had holding it down. Very tough material! It is sold for replacing glass in security windows, since you can beat it with a hammer and barely dent it. Cuts beautifully with a hacksaw or a metal-cutting blade in a power jigsaw. Doesn't crack like acrylic.
While you are at Home Depot, look at their other halogen bulbs. They have a 250 Watt wide pin capsule bulb with a pretty short filament. The 100 Watt wide pin capsule bulb filament is less than 1" long, and the bulbs are small enough that you could put three of them together in a triangular stack. But that would be about $20 total for a lamp rated for only 2000 hours.
stopped before i started.
So, my project came to a nasty stop before i started. Grabbed my stuff on sunday and headed to the shop. (I have access to a full machine shop with electronic testing capabilities on the weekends.) grabbed my antistatic wrist strap and a screw driver and tore into the lcd.
What a *****. it was put to gether in such a way as to be useless for projection. too many ffc, to bother with not to mention it was mounted to a piece of metal that i couldnt figure out how to remove. so with no useable lcd, my project is dead until i buy another one. on the upside though, the screen as is is kinda nifty. I think i'll nstall it in my car next weekend. (now to buy a mobile dvd player)
well, i figured i'd start building the light engine and did that ok, but a mistake with a drill press scratched the heck outta my condesner lense. (Stupid mistake on my part, I take the blame, and dont want to talk about it.) so the project is being shelved for a while until i order a new lcd, new condenser, and probably new light source (the halogen i bought is real yellow, noticed it when we fired it up after wiring it up to test the light source).
On, the upside though, i did play a bit with the light pathes (had nothing else to do) and looks like my design is sound. Wish me luck on my next attempt.
So, my project came to a nasty stop before i started. Grabbed my stuff on sunday and headed to the shop. (I have access to a full machine shop with electronic testing capabilities on the weekends.) grabbed my antistatic wrist strap and a screw driver and tore into the lcd.
What a *****. it was put to gether in such a way as to be useless for projection. too many ffc, to bother with not to mention it was mounted to a piece of metal that i couldnt figure out how to remove. so with no useable lcd, my project is dead until i buy another one. on the upside though, the screen as is is kinda nifty. I think i'll nstall it in my car next weekend. (now to buy a mobile dvd player)
well, i figured i'd start building the light engine and did that ok, but a mistake with a drill press scratched the heck outta my condesner lense. (Stupid mistake on my part, I take the blame, and dont want to talk about it.) so the project is being shelved for a while until i order a new lcd, new condenser, and probably new light source (the halogen i bought is real yellow, noticed it when we fired it up after wiring it up to test the light source).
On, the upside though, i did play a bit with the light pathes (had nothing else to do) and looks like my design is sound. Wish me luck on my next attempt.
DOH! now i get it.....
After some thought and reconsideration... I figured out the whole focal length on the objective length thing. after playing with the calculator at lumen labs i figured it out. 80-100mm would be very very wrong unless i was going to try to build a rear projection tv (which isnt out of the question). I have since ordered a new projection lense from surplus shed, its a new fujinon lense with a fl of 290 mm. maybe a bit higher than i wanted but why not. i'll set the thing up to have replaceable lenses or something. shouldnt be too hard.
Also had a really neat idea. Instead of running a cable to the projector for the video signal, i'll use one of those rf video transmitters like they sell on x10 and everywhere else. I had thought of building into the design a portablt dvd player like they have at www.mp3playerstore.com but then i'd still need to run a cable for sound. plus this way i can use a simple av switch to go back and forth betwen my tv and pj.
A new idea i have is I am going to try to cannabilize the focusing motor out of my slide projecter for use here with the new lense. I mean i could just make a focussing box or something but this just seems cooler. And maybe use a motor and threaded rod system on the second fresnel to do a sort of motorized keystone correction systerm. just need to find a proper gear box.
I'm also going to save myself the problem of building inot a pc case for now and just build a custom box outta wood. Probably next week i'm going to order a innovatek 7" xga lcd. The last step will be something like finding a suitable light source. maybe the 400 watt kit at lumen labs. given it will bump the price up to more like 425 instead of 125, but why not.
everything should still work out ok.
Anythoughts comments etc?
After some thought and reconsideration... I figured out the whole focal length on the objective length thing. after playing with the calculator at lumen labs i figured it out. 80-100mm would be very very wrong unless i was going to try to build a rear projection tv (which isnt out of the question). I have since ordered a new projection lense from surplus shed, its a new fujinon lense with a fl of 290 mm. maybe a bit higher than i wanted but why not. i'll set the thing up to have replaceable lenses or something. shouldnt be too hard.
Also had a really neat idea. Instead of running a cable to the projector for the video signal, i'll use one of those rf video transmitters like they sell on x10 and everywhere else. I had thought of building into the design a portablt dvd player like they have at www.mp3playerstore.com but then i'd still need to run a cable for sound. plus this way i can use a simple av switch to go back and forth betwen my tv and pj.
A new idea i have is I am going to try to cannabilize the focusing motor out of my slide projecter for use here with the new lense. I mean i could just make a focussing box or something but this just seems cooler. And maybe use a motor and threaded rod system on the second fresnel to do a sort of motorized keystone correction systerm. just need to find a proper gear box.
I'm also going to save myself the problem of building inot a pc case for now and just build a custom box outta wood. Probably next week i'm going to order a innovatek 7" xga lcd. The last step will be something like finding a suitable light source. maybe the 400 watt kit at lumen labs. given it will bump the price up to more like 425 instead of 125, but why not.
everything should still work out ok.
Anythoughts comments etc?
ok, my lenses came in yesterday and they look great. the fujinon won't fit into the motorized focusing housing, but i'm sure a bit of work with the dremel, and maybe a hose clamp should get it mounted no problem. nice lense, this thing has some real weight to it, looks much better built than my lense from the slide pj.
should start building this thing this weekend or so. Maybe just get the case started after i fine tune my lense distances this week.
should start building this thing this weekend or so. Maybe just get the case started after i fine tune my lense distances this week.
You wouldnt happen to have any more links to 500W Haligens would you?
I have looked almost everywhere around my town. I just dont know alot of places on the web.
I have looked almost everywhere around my town. I just dont know alot of places on the web.
I just picked mine up at home depot for like 15 bucks or so. Not a good light for this project though. Wrong color by far. never noticed how yellow the light was until i tried to use it for this project.
Everyone here seems to like the MH bulbs and i dont blame them. if you purchase from 1000bulbs.com you could get every thing you need for about 100 bucks. Thats the route i think i'm going to go.
Everyone here seems to like the MH bulbs and i dont blame them. if you purchase from 1000bulbs.com you could get every thing you need for about 100 bucks. Thats the route i think i'm going to go.
decided against using the pc case for now and built myself a modified pico case. It's 12 inches wide instead of 9 to allow more testing with different light sources.
Here's some of my components
Here's the ohp I'm stealing the fresnels and light source from, the light source may be temporary I also have the slide projector light source to mess with too.
Here's the case sofar
Here's the case a bit closer
Here's the mess i made while building 😀
Here's some of my components
An externally hosted image should be here but it was not working when we last tested it.
Here's the ohp I'm stealing the fresnels and light source from, the light source may be temporary I also have the slide projector light source to mess with too.
An externally hosted image should be here but it was not working when we last tested it.
Here's the case sofar
An externally hosted image should be here but it was not working when we last tested it.
Here's the case a bit closer
An externally hosted image should be here but it was not working when we last tested it.
Here's the mess i made while building 😀
An externally hosted image should be here but it was not working when we last tested it.
Ok, got my condenser mounted. And fresnels cut. I forgot how nice the smell of melting plastic or acrylic in this case is.
Condenser.
Condenser again
Yup, another of the condenser
The fresnels, cut to the dimensions of my stage, the edges arent pretty but it works.
More as i progress.
Condenser.
An externally hosted image should be here but it was not working when we last tested it.
Condenser again
An externally hosted image should be here but it was not working when we last tested it.
Yup, another of the condenser
An externally hosted image should be here but it was not working when we last tested it.
The fresnels, cut to the dimensions of my stage, the edges arent pretty but it works.
An externally hosted image should be here but it was not working when we last tested it.
More as i progress.
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