| Skeeter-MTI |
Hello everyone.
I have been reading the fourm for about a month and have been picking up parts along the way. I have gotten about nine fans. Four 12v and the rest are 120v. I have four older OHP to get parts from.
My plan is to build an enclosure of some type.
Only one of the OHP has a working lamp inside. It's lamp assmbly is a 600W, double ended, Halogen bulb and it is BRIGHT:cool:
I have read that the 250W MH is the bulb of choice, however poor men have poor ways.
Will my 600W Halogen be too much light or too hot for this type of project?
Any help is greatly appreciated.
MTI stands for:
M=multi T=talented I=individual |
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| Video Freak |
| Hey Skeeter, Hummm there isnt really a way to know, you just will have to try it out without a lcd kae the temp and then decide what amount of fans you will need Im thinking 2 would be good, But its a experamant type deal. Good luck. |
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| Dwiel |
If I were you, I'd make sure you put a piece of UVA and glass in there before the LCD to protect it. The UVA is plexiglass, you can get for real cheap that stands for Ultra-Violet Absorbant, and will obviously block the ultra violet from getting to your LCD and damaging it. The glass will block IR (heat). With such a high wattage bulb, I am not sure how much IR and UV it will put out, but I would guess that it is more than normaly, and so should definately be protected against.
Also, I have a 250w HQI and a cmv1512 and have a setup right now that, believe it or not, is almoast too bright. All of the bright colors are very bright. I think I need to adjust the gamma or something, but if anything you can put something before the LCD to block some light right? you can always block some out... much harder too add ;-)
Hope I've helped. |
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| Lori |
My overhead had a 600W halogen in it and it didn't get extremely hot as long as the fan was running. It was the original fan that was in the unit. It did overheat when the fan quit, but I knew it before any damage was done because the fresnel started to get hot and warp, when I saw the picture getting screwy because of the warping, I got it shut down before any damage was done.
I replaced the fan and things were fine. The halogen lamp was not too bright even with a brand new bulb. Actually I am positive it is brighter (and whiter light) with the 400W MH I replaced it with. Again, I just have one fan and it gets warm, but not hot as long as the fan is running. I would say two fans would be sufficient.
Edit - I say no damage was done. I mean to the lcd. The fresnel was toast. |
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| troymasons |
Mate have you got a 400MH inside your ohp??
Im a newbie and would like also to do this have you got any pics you can post???
TROYBOY |
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| Lori |
| Yes, the 400 watt is inside the overhead and it was no small feat to get it there either. This is all temporary until I can purchase the lcd monitor I want to tear down and build an enclosure, but it does extremely well for what it is. Are you wanting pics of the projection or of how I stuffed that big old bad boy lamp in that projector? |
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| troymasons |
Both would be awsome???
Thanks Heaps!!
Troy |
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| Lori |
Ok, you asked for it.
Disclaimer****
I never said this setup was pretty. I said it gets the job done, your mileage may vary.....
I threw up a quick and dirty page with current pictures and a link so some pics before I swapped the halogen for the halide. Colors are much better with the halide.
It's about as ugly as a box can get, but we are pleased with the image when running through the laptop. There's quite a bit of commentary on the page, but I figure more info is better so you can compare apples to apples.
Either way, I know I'm gonna get dogged for the way this thing is put together.
http://www.lovemyoldhome.com/projector |
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| troymasons |
| You absolute legend!!!!!!!!!!!!!!!!!!!!!!!! |
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| troymasons |
This is nothing to be ashamed of, good job!!!!!
That is definitly what i will do as my first attempt!
iI am running a qa1200 with an old 250watt halogen lamp Bell & Howell OHP not bad results but im sure the 400wattmhu will kick its butt!!
Thanks Troy!!!!! |
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| Lori |
In retrospect, a few things to do differently than I did if you think you want an ugly monster like this, but it is a cost effective way of reaching a goal...
Mount the ballast on the outside rather than inside with the bulb and run your wiring outside. I'm afraid my wiring is going to get brittle sooner or later in there with the bulb, and it may have some bad effects on the ballust. If I were to do it again, I'd put all that stuff outside the case, but you need to find a way to shield it from someome accidentally getting zapped, so make some adjustments on those points. Also, unless you can put something protective around the holes you put through the case, make sure to protect your wiring to keep it from getting cut or wearing on the rough edges where it goes through the case.
If you aren't worried about looks at this point, fine, I'm living in a glass house on that point, but do make sure it's wired up and shielded so you and others are safe from electrical components.
That lamp and ballust was around $68.00. It was a commercial fixture I purchased as a whole unit and tore it out of it's case. |
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| troymasons |
Mate cost $135au for all the gear over here! Ithink ill go with gear on the inside but shield it!
Do you mind if i email you any questions if i get stuck??
Will probably start next weekend.
Any idea of lumens after LCD??
What ie the heat like??
Mate there is nothing like the brute force approach!!!
Thanks for you assistance.. |
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| Lori |
of course you can mail me. lori@lovemyoldhome.com or lehd@sctelcom.net
I will help all I can, but there are others here who do a much better job than I did....... but I will answer anything I can.
Not like I'm worried about someone stealing my design or something....... ;) |
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| Skeeter-MTI |
I went with the 600W halogen bulb and installed it in a OHP that had a very good fan in it. I also added 2 12v compuret fans blowing in on the bulb.
I am using a passive matrix LCD and an older computer for testing it out.
Upon first starting everything up the image is fantastic.
NOW for the BUT!
As I'm playing freecell the cards are sharp at the edges of the screen but the center starts to wash out like it is getting a hot spot. I read about hot spots in some of the other threads but they are getting them from the start. Mine dosen't do it untill it has been running for about ten to fifteen minutes.
I cheked the heat inside the case and it is not getting that warm. I don't want to put a good panel on this thing untill I figure out what's going on.
All comments welcome.
Skeeter:cool: |
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| Lori |
I get hotspots when:
Poor screen material.
Improper focusing light/fresnel/lens (combinations thereof)
Reflector angels off
Fresnel warped
My 400 watt halide blows the 600 watt halogen I had all to bits. |
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| 18wheeler |
| probably your lcd was overheat. different LCD act differently when overheat. Mine will get dark when it is overheat. add a few fans for the lcd. |
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| Lori |
Maybe I should also add, like 18wheeler said, that halogen, if you don't have good cooling is going to be hotter than a halide bulb, I got dark spots when the fresnel got too hot before and warped. That was with the halogen, but it can also happen with the halide bulb when you throw in other variables....
I tried adding what turned out to be a poorly shaped reflector that concentrated so much heat/light that even the fans didn't help, it started to melt the middle of the fresnel and I got dark spots again. So, even with cooling that is sufficient for one situation, you can still have problems if you change other variables. |
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| ace3000_1 |
| quote: | | As I'm playing freecell the cards are sharp at the edges of the screen but the center starts to wash out like it is getting a hot spot. I read about hot spots in some of the other threads but they are getting them from the start. Mine dosen't do it untill it has been running for about ten to fifteen minutes. |
Heya buddy, thats the lcd's center getting too hot, i bet it gets abit darker in the center too, its also normal to have hot spots, all projectors have them, its the way lenses work, to help take away a hot spot either a small ajustment can be made on the condenser or changing the condenser with another condenser that has a closer matched focal length, most hot spots are due to the condenser having the wrong focal, the frensels focal is out with the condenser, or its miss alighed, reflectors can also play a roll in this but the condenser is the main culprit.
Trev |
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| Skeeter-MTI |
Thanx Trev,
What if I don't have any condenser lends? Cause I don't. The light points straight up at the frensel. It had a louvered box around it that could swing open for buld replacement. I left the box open for a test and it did not get as hot inside the bulb area.
The box works good to prevent light leak but I think I'm going to cut it down to where it barley comes up to the edge of the light. So that the air flow can go accross the top of the light area and help keep it cooler.
I will place the light as far to the bottom of the OHP and adjust it up until I acheave the desired results.
Can you tell me how to obtain copy's of you plans and how much they are? I've read all kinds of things in this fourm and yours and crusers projectors is kinda where I would like to end up. Using allen's 250W MH light engin.
One last question. How do I attach pictures like I've seen. I would post pictures but I can't seem to get it right. Is there a POSTING PICTURES FOR DUMMIES located somewhere in the fourm?
Keep up the good work everyone this is TOO much fun!!!!!:D |
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| ace3000_1 |
| quote: | | What if I don't have any condenser lends? Cause I don't. The light points straight up at the frensel. It had a louvered box around it that could swing open for buld replacement. I left the box open for a test and it did not get as hot inside the bulb area. |
heya buddy, ok no condenser lens, then in this case the focal must be out from the frensel lens to the light, im not saying this is the problem 100% but this is what it seems like to me, i would recomend a condenser lens, the image will be much brighter and condensers do eliminate hotspots if its the right one. Get the image brightness as even as possible and then id be inclined to run a couple of fans over the lcd to cool the area as 18wheeler sujested.
| quote: | | I will place the light as far to the bottom of the OHP and adjust it up until I acheave the desired results. |
Yep, try this to see if you can get it any better then what it is now, its not that hard to find a sweet spot on a frensel's focal length. just make sure u do fine ajustments and not big increcments lol.
| quote: | | Can you tell me how to obtain copy's of you plans and how much they are? I've read all kinds of things in this fourm and yours and crusers projectors is kinda where I would like to end up. Using allen's 250W MH light engin. |
Ok the plans of mine arent finnished as of yet, im hoping very soon, they will be $45 and very comprohensive. They will cover guidlines for noobies and for the more advanced with a few hints along the way. They will also have all sizes and angles to make an exact copy of the one that im still currently making today, but it shouldnt be too much longer until all is done. The plans at this stage are for a 150w CDM-T metal halide bulb, but i will have an update very soon after for the 250w HQI lamp.
| quote: | | One last question. How do I attach pictures like I've seen. I would post pictures but I can't seem to get it right. Is there a POSTING PICTURES FOR DUMMIES located somewhere in the fourm? |
lol ive taken a screen shot for you, at the bottom of the posting page you need to browse for a pic that you intend on sending, the size should be about 640x480 pixels, or it wont be allowed to be posted and will get rejected. It says to the far left attachments, ive circled this for you so its easyier to follow.
Trev |
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| Skeeter-MTI |
Thank ya'll for the help.
I've tried adding an extra fan blowing air on the bulb and cutting down the metal box around the light engin. But it still gets hot. I guess it is time to change to a MH 250W system and build an enlouser. I was unable to find some uv glass as of this date. I'll keep looking while I check on the MH bulb set-up.
Here is a pict of the current light engin set-up as tested. |
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| Skeeter-MTI |
I followed the instructions from ace's reply. It did not work. Here's my second attempt.
It did not work; me not smart. |
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| Skeeter-MTI |
Hey it works! :) The pictures came out on the screen!:)
I are smart:cheerful: |
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| ace3000_1 |
LOL somtimes it can take abit to come up, but u got it going now. :)
Trev |
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