PART 2 PARABOLIC TROUGH DIY reflective mirror HUGE SOLAR REFLECTOR

[sibalogh]

Hi Dan, can you, or anyone, tell what is a cheap yet good black coating on sufaces to collect sunlight with that is also reasonably durable?

[athlon866]

Obviously you skipped your high school functions. You only need a quadratic function, and you draw a graph. That's it!

[MrSirPhase3]

@athlon866 Obviously you have a much better solution, So, Don't just tell him what he did wrong........Get out yer video camera and show us yer quadratic function and draw a graph...............You've made er Sound easy, so show us how........

[73roadrunner1]

Man, Youn sure do this the Hard way !!!

[MrSirPhase3]

@RB13240 We look forward to your video showing us an easier alternative.

Dan has at least given the viewer an idea to start with. It's good to have people like him and his Wife sharing their idea's. Can't wait to see your video's RB13240.

[MrSirPhase3]

@RB13240 Hey Aerospace engineer, I like the pretentious attitude. Don't get yer panties in a bunch.

[MrSirPhase3]

@RB13240 LOL...I spend all this time tryin to get ya all riled up and it just aint working. Darn Pantie wearing Aerospace Engineers.....

:)



[harmonicgrunt]

is he taking DRUGS?☺

[PhysicsGuerrilla]

To find the depth of a parabola that corresponds to each radius point along a straight line... Depth =Radius point squared divided by 4 times the desired focal point distance. d=R²/(4*f). See Dan's website for my Excel Spreadsheet

[algae1000]

Hi Dan- Rather than trying to transfer a known parabola from a dish to make a duplicate, look up parabola in Wikipedia, you will find some illustrations showing you exactly how to draw a parabola with any focal length you choose. Much easier and quicker than trying to match a dish that may not be the focal length you want. You can also reduce the weight by using just half the number of pegs if you use bender board on the pegs first, as a backer, then the acrylic goes on. Even stronger.

[GREENPOWERSCIENCE]

Check our website, I have an excel doc that works really good.

[blckjade05]

Question if you can, whats more reflective, aluminum, mylar or a parabolic mirror?

[GREENPOWERSCIENCE]

@blckjade05 Mirror, Reflective Adhesive, Aluminum Polished, Mylar, Foil, Spray paint.

IN THAT ORDER>

[blckjade05]

Thanks, one last question thou

Cost Vs Reflectivity Vs Weight

which material would have the best balance of all these?

i would like the mirror, but not if its too expensive, someone told me mylar would be the way to go.

i would like to redirect largest amounts of light possible and im trying to figure out which material would produce the best light, not too heavy while being very economical

thanks for the answers again, your vids help alot.

[Jas0nphilly]

could you show me how to make a telescope that size :)

[tbenefi33]

Where you get the dish that would be a good parabolic microphone.

[unknotmiguel]

i like your way of being... natural and this is school..

[RMCrowley]

I wonder if I could cast iron with the Fresnel lens?

[GREENPOWERSCIENCE]

You can cast hybrid. Electric and solar. Basically use 75% less fuel. The sun alone can do small amounts with a large Spot Lens.

The problem with large amounts of metal, heat sink.

Hybrid works great

[sirnicholson]

is he searing his words?

[md22mint]

Thats a good saw safety tip. What miter saw under $250 would your recommend? Can those saws cut aluminum angles (for a photovoltaic solar panel)? Will you be making a photovoltaic solar panel any time soon? Best regards.

[GREENPOWERSCIENCE]

Hi,

This one is a "Hitachi" that cost $149 10" blade. I like the cheaper ones because they are direct motor vs a belt. For aluminum you swap the blade to an abrasive wheel. It works good for that.

[matrixm777]

Keep up the good work, Dan. Thanks for the post...

[1clevername]

What's the point of showing us all these parabolic mirror vids? Do they have any real use or are they just cool to play with. Let's see one in a practical setting doing something.

[muddymuddymuddmann]

HEY DAN, Nice teaching technique. Thanks for the miter saw safety. This is a cool video with pretty neat way of making the paraboloid trough. Cant wait to see the power results of this much area of collected solar energy.

Is this one for steam or just hot water?

MUDDy

[jab0805]

I really enjoy your videos. I've learned a great deal from you. Thank you Dan.

[squirrelbong]

i love your videos dan, but personally would have just built it like a skateboarding haflpipe, with a parabolic curve....2 end pieces with horizontal beams..seems like a lot less work/weight

[jwwm2]

Dan, I love your videos, but you make some time-consuming mistakes in this one. 1) It's easy to draw a parabolic line using measurements and a straight edge. Far easier than your method, more consistent and easier to know where the focal point is. Goog it. 2) Once the line is drawn on paper, transfer it to plywood, make 3" or 4" parabolic strips of plywood, and support them with far fewer 2 bys. This will be stronger, faster, lighter, easier, and more consistent. Believe me.

[GREENPOWERSCIENCE]

The plywood works but it is heavy if you do it like a skate ramp design, this trough only weighs 70 pounds so it can be raised to the roof with two people.

Each set of peg supports only weigh 2 pounds, 3/4" plywood weighs 12 pounds+ for the same curve. Also the cuts of plywood requires some good jigsaw or band saw skills.

[IdahoViewing]

If you want accurate lengths then use a small block and clamp to establish the length rather than a marked line. You will be assured an EXACT duplicate each time.

[killakobra]

instead of using line on the crop saw fence that you have to look at to line up, you can use a c-clamp and a small block of wood to set the piece against. saves alot of time over 20 pieces

[speedbrew]

Funny, I have used miter saws all my life a never noticed those black lines.

Guess common sense goes along ways.

Learn something everyday.

[VisionQuest2012]

One of the most crucial elements in harnessing the sun is tracking the sun. Will you be doing any tracking with sensors or some other means? That would be some valuable info. Thanks and great video.

[jmincher3]

Jeez...I found an instructional video on Youtube covering exactly that. It looked pretty easy...but I have lost the link. When I find it again, I'll post it for you.

[VisionQuest2012]

Thanks. That would be a crucial piece of the puzzle here.

[OneEyedCyberchicken]

GO DAN!!!!!!.. love em.. ty for your videos!

I hope to share the projects ive done thanks to you sometime

[CTOL1]

You know, we all think differently, I at times go about projects much like you do, so it is refreshing to see this. If it was easy, then anyone could do it.

I had a room mate that was a master craftsman with all things wood and it was just remarkable to watch him.

I am not saying any way is better and we all learn as we go.

Thanks for all of your efforts it really is a blessing to have you to share as you do with the planet.

5* keep em coming

[Duckeieio]

I think this is why GOD created plywood just cut a stack-O-sillouetts and space them at stations works for boats. Just a thought, in no way should you interpret this comment as ingratitude I am a loyal fan love your work but as a boatbuilder it is excrutiating to see someone go through the process without realizing they are reinventing the wheel.

[GREENPOWERSCIENCE]

I used this method because of weight. The pegs only weigh 2 pounds per section. 3/4" sturdy plywood with this cut would weigh about 12 pounds per section. So this saved about 50 pounds. With the mirror the entire trough weighs about 70 pounds. Also the stadium look is prettier.