DIY Multimedia LED Projector (video manual)

Step 13 Cutting the Fresnel Lens

 
When cutting the fresnel lens you could use many tools. I decided to use the angle grinder to be quicker, but this is not a toy, is very dangerous if you don't know how to use it. You should wear a mask (the fumes from the fresnel when cutting aren't very healthy), safety glasses and gloves. But you could cut the fresnel with a dremel or some other thing.

1.- Mark the centre of the fresnel. (see the video to know how to)

2.- Use some masking tape to protect the fresnel as any big marks on the fresnel will be visible on the projected image.

3.- Now that we know the centre of the LCD, we want to do the same on the fresnel. So measure the space from the base of the projector and the circuit, paying good attention to the center (see the video to know what I mean. Do your best, if its not right right on the center is still ok)

4.- After cutting the fresnel, tape the borders to stop the fresnel coming apart, or dust getting in between them.

Comments

[aekara]

hi newtoon :) i was thinking of buying this


http://cgi.ebay.com/XL-Full-Page-3-Power-Fresnel-Magnifier-Magnifying-Sheet-/300390430052?pt=LH_DefaultDomain_0&hash=item45f0aa3564


will it work or i need to buy a OHP fresnel lens?

please help me

thank you in advice

[newtonn2]

I don't know. I never try it before. If you want to make sure.. buy the OHP lens. Or you can try the magnifier glass, it's not too expensive anyway.

[aekara]

thank you

i am going to buy a OHP fresnel lens becouse i want to make sure that it will work

[aqueel125]

Can I use magnifying sheet instead of fresnel lens?

[Ngdbud]

I have yet to try it, but that's what i'm going to use. Magnifying sheets are Fresnel lenses. The sheets can be pretty flimzy though. Make sure you come up with a mounting bracket to hold it straight. Any warping will probably distort the image. I'm still waiting on the screen and LED I ordered to come in, but I'm going to use a sheet of plywood or sheet aluminum to hold it flat.

[Ngdbud]

I don't completely understand, is there a lens on either side of the LCD? and is there any space between the LCD and lens?

[007.sammy112]

 i cant find fresnel lens , so can i used ordinary magnifying lens

[jonathansinkimee]

well done newtonn2...   i`m doing one soon.. diy projector... By the way great instructables!!!! :P

[newtonn2]

 Thank you very much!

[KcPower]

Is there anything else that I can use because i can't find  any fresnel lens?

[newtonn2]

 Not that I know? Are you sure you can find any fresnel lens? They are call sometime magnifying lens.

[KcPower]

(removed by author or community request)

[newtonn2]

Try to find one that is made of hard plastic.

[jj.inc]

 So you have one lens a little way in front of the LCD?

[newtonn2]

 
The fresnel lens goes just before the LCD.