Fresnel Lens Project based on Urban Survivalist

[Matt In Oklahoma]

Fresnel Lens
This post is based on the idea presented by Urban Survivalist and his Fresnel lens post which motivated me to begin a project. https://www.survivalandpreparednessf...t=fresnal+lens
Much to my surprise my wife got onboard and my son as always was up for the challenge.
My wife brought home a broken overhead projector from work that was being discarded.


We took it apart and got several useful lenses and a mirror out of it.

We began using scrap wood for this because truthfully we don

[Matt In Oklahoma]

Ok finally obtained a boil. It has been hazy and partly cloudy and took me almost 4 hrs to get there but I ended up painting the back of a half filled water bottle black. Conditions were less than perfect but what I would consider “normal”. This is a must try. Thanks again urban for posting it and showing us how! Now to get a projection TV……

Right at the end you can see some of the bubbles on the camera. The camera didn’t pickup a lot of what I could see.

[Urban Survivalist]

Congradulations Matt. You are on track and once you get a large rear projection big screen fresnal lens you are going to be burning everything in sight like a kid with his first magnifing glass. LOL. Hey good job and keep up the great work. Next I will get you in to large parabolic mirrors and see what we can do with that. hehe.
PS you can see bubbles rising in the water bottle indicating a boil which is far past pasturazation.

[Urban Survivalist]

One thing I forgot to mention is to run your finger nial on both sides of the lense the smooth side is the side that faces your project the side with the ridges is the side that collects the light. both sides will burn but the smooth to your project will be hotter and have a better focal point. I guesas that was kinda important and should have been stated before. Sorry about that I just thought of it.

[Matt In Oklahoma]

One thing I forgot to mention is to run your finger nial on both sides of the lense the smooth side is the side that faces your project the side with the ridges is the side that collects the light. both sides will burn but the smooth to your project will be hotter and have a better focal point. I guesas that was kinda important and should have been stated before. Sorry about that I just thought of it.

Good to know, we just played with it till we figured out which side and wrote "This Side Up" on the board holding the lens for whoever in the family uses it next. Getting this busted projector for free and using scrap wood and screws/bolts from my leftover bin made the whole project pretty much free.
One thing I can say, don't leave it laying around or uncovered, this aint no toy. This puppy will set the yard on fire in about 1-2minutes!
We also cooked some ultimate survival food on it too. Marshmellows!!! Can't be running around all uncivialized eatin raw marshmellows like savages now can we. LOL

[TyrannyUnleashed]

This is great advice from the both of you. I am now going to keep an eye out for old projectors.

As always, Thanks for the great tips, and help.

[barfife]

Good to know, we just played with it till we figured out which side and wrote "This Side Up" on the board holding the lens for whoever in the family uses it next. Getting this busted projector for free and using scrap wood and screws/bolts from my leftover bin made the whole project pretty much free.
One thing I can say, don't leave it laying around or uncovered, this aint no toy. This puppy will set the yard on fire in about 1-2minutes!
We also cooked some ultimate survival food on it too. Marshmellows!!! Can't be running around all uncivialized eatin raw marshmellows like savages now can we. LOL

Hope to get "Godzilla the Fresnal Lense" (63 inch!) up and running this weekend.

[Matt In Oklahoma]

Hope to get "Godzilla the Fresnal Lense" (63 inch!) up and running this weekend.

Can't wait to see it!!

[Cimarron]

So will this work with any lens? If not what characteristics should I look for in a lens? Like if i'm looking through it does it need some magnification?
Obviously you guys aren't talking about any piece of glass but will any screen lens work?

[Matt In Oklahoma]

So will this work with any lens? If not what characteristics should I look for in a lens? Like if i'm looking through it does it need some magnification?
Obviously you guys aren't talking about any piece of glass but will any screen lens work?

On the TV it needs to be the projection type that has the sngle bulb in the back or something like this projector that has a magnifying lens.

[claymore]

Nice project everyone, congrats. You might want to check out American Science and Surplus (www.sciplus.com). This place use to have giant fresnel lenses, but looks like only smaller stuff now. Lots of items here (much of it cheaply made, be careful).

[Jeremiah2913]

So will this work with any lens? If not what characteristics should I look for in a lens? Like if i'm looking through it does it need some magnification?
Obviously you guys aren't talking about any piece of glass but will any screen lens work?

don't quote me on this but I believe any tv greater than 36" before the hd age should have one with the possible exception of DLP units. They are also probably very abundant in stores marketed as magnifying lenses, they will be flexible and as mentioned have a rough and smooth side.

[Jeremiah2913]

Fresnel Lens
This post is based on the idea presented by Urban Survivalist and his Fresnel lens post which motivated me to begin a project. https://www.survivalandpreparednessf...t=fresnal+lens
Much to my surprise my wife got onboard and my son as always was up for the challenge.
My wife brought home a broken overhead projector from work that was being discarded.


We took it apart and got several useful lenses and a mirror out of it.


We began using scrap wood for this because truthfully we don’t have a clue what we are doing. We may build a better model at a later date.


The other lenses we are playing with and they are very good!



I have a black pot of water with a lid on. We will see how long it takes. Today it’s cloudy so it’s touch and go this morning, but I’m not complaining the rain and cooler temps are wonderful! The lens is smaller than Urban’s TV lens but I can tell you to use caution when doing this. My son was holding it and when the clouds moved away the sun burned his arm in seconds! It was kinda funny and I’m glad this lens is a plastic rather than glass. The focal point on this appears to be around 5-6 inches away from the lens. I can tell you it will burn a wet leaf in less than 1 second and raise a blister in under 2 seconds.
Thanks Urban, this is a great DIY project!

nice work on the experimentation. Your son getting burnt a bit reminds me of Hank from king of the hill. "Do you want Bobby to get burnt?" "well maybe just a little!"

[Matt In Oklahoma]

nice work on the videos and experimentation. Your son getting burnt a bit reminds me of Hank from king of the hill. "Do you want Bobby to get burnt?" "well maybe just a little!"

hahahahahaha cant say I didnt enjoy it some hehehehe

[Jeremiah2913]

hahahahahaha cant say I didnt enjoy it some hehehehe

lol, someone will want to call DCSF on us both but a valuable lesson was learned with minimal damage done. He has respect for mother nature and could quite literally save his life one day. Good to see him involved and learning from you!