Lilliput projector from Toronto, Canada

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go77306

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Joined 2004
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#1
Hi, finally I started to build my first DIY projector!!!

7" lilliput (800X480) VGA input
150W Philips CDM bulb
200 mm fresnel
240mm FUJICON copy lens (bought it one month ago, haven't received it yet :-(((

The design is vey much similar to Chasse's desing.

here is a few pictures of the light box (not finished yet):
 

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#7
This is the reflector I am using... bought from home depot.

Do you guys thing the surface is ok? Do I need to stick some aluminium duct tape on the inner surface? I am worry about the heat. 5 minutes after I turned on the light, the reflector is hot. If the inner surface get hot, I am afraid the aluminium duct tape will get loose... will it?
 
#9
heya buddy lets take a look at somthing, what can handle more heat? the duct tape or the metal reflector?

Dont go putting duct tape in there or you will have a fire, period, just leave the metal reflector the way it is, polish it if you want a better surface, duct tape is crap man and a fire hazzard. Dont go putting anything near that light that cant handle atleast 300 deg c.

Trev🙂
 
#11
Still waiting for the frenels, mirror and lens to coming from DIYBUILDERGROUP. Ordered on July 29th, today is Sept 04, haven't received yet! Probably I am just in bad luck! I don't know where is the original order sent via USPS, apparently the second order sent via UPS disappeared too!!!
The status on UPS' website isn't get changed since Aug 31st!

Status: Billing Information Received

Shipped to: TORONTO, ON, CA
Shipped or Billed on: 31 Aug 2004



Tracking Number: 1Z 69T *** 68 **** *** 0
Service Type: STANDARD
Weight: 3.00 Lbs
Note: UPS has received shipper's billing information electronically. Billing information received does not indicate shipment pickup or drop-off. Please contact the shipper for more details.


I AM SO FRUSTRATING!!! I orderred it on July 29, I hoped I could receive it in the first week of Aug, I dreamed! After jcb sent the replacement order, I thought I couldn't be able to work on my project this long weekend, I dreamed AGAIN!

I AM DYING!!!!!
 
#13
Finally got it!

Fresnel: 200mm (9inch) FL
Lens: 240mm FL
PAR reflector: 5 inch
lamp: 150W cdmt

I built the lcd mount and fresnel mount yesterday. I have 3 problems:

PAR reflector -> lamp -> fresnel -> lcd -> projection lens

1: I am using a 120mm computer fan (>80cfm I guess), I still feel the LCD is kind of warm, the fresnel is fine.

2: the image is dull. (I don't have a box yet, so there are some indirect/direct light on the screen). Will put all things into a box help a lot?

3: what is the best distance btw lamp and fresnel? I think the lamp shouldn't be put on the focus length of the fresnel, since I am using single frsnel design, right?

4: what is the best distance btw fresnel and lcd? 1-2 cm or 5cm?

5: I have another piece of fresnel (same focus length, 200mm/9inch). can I put this between lcd and projection lens? Will this give me a brighter image?

Thanks
 
#18
ace3000_1 said:
Heya GO, are you using a single page mag? if so wrong frensel and configeration.

Trev🙂
Click to expand...


I am using single piece of the fresnel bought from diybuildergroup. It actually is this:

http://www.3dlens.com/enter.html?target=Large_Fresnel_Lens.html

[quote from 3dlens]
260mm x 260mm
Item: #A260
Transmittance: 93%
Thickness: 1.8mm
Weight: 160 grams
Material: optical acrylic
Groove pitch: 0.2mm
Focal length: 200mm

The most efficient and high groove density large fresnel lens is excellent for 100-150" TV projector home theater with very clear projection image. Lens can provide superior overall efficiency in the collection and focus of light..
The lens is also excellent for reading.
[/quote from 3dlens]


I have seen people using the same optics to built projectors with good results:


http://www.diyaudio.com/forums/showthread.php?s=&threadid=33384&highlight=
 
#20
I have another piece laying around... you mean I need to put 2 piece fresnels together and put it between lamp and lcd?
Click to expand...

Well....... in your case it may be best too, this is because that reflector of yours has probally got crapy specs for producing paralelle light, im not saying its crap but you need to find a way to make it work, id start by atleast polishing the inside of the reflector to a mirror shine.

Next thing is the frensels, 93% transmisive? not very transmisive for the price, are they hard page maggs or are they actual split frensels? cos hard page maggs loose you light just like the thin ones and they dont work to well.

200mm focal is also too short for the copy lens, its better to have a frensel with a longer focal then having it too short, the longer ones seem to work better on a projection lens with that focal, ( i asume it the copy lens). 210mm focal frensels are fine cos we can actually get the frensel to work at 210mm from the projection lens with having the frensels split.

Trev🙂
 
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