Soooo... How 'bout that Cubic Zirconia, eh? [Most Likely DANGEROUS]

So I was just browsing Wikipedia when i fell upon the page about Cubic Zirconia. It turns out, that the basic principles of synthesis don't look all that complicated. So I was wondering, if anyone knew of any plans for a small skull crucible that were floating around the net.. I probably wouldn't use it for zirconiua, seeing as it needs around 2700 degrees Celsius to change structure (this is the dangerous bit), but it might be a fun introduction to induction heating. Also, it's a pretty awesome way of eliminating the need for a refractory when melting stuff (keeping a solid layer of the material as a shell instead). I think I could build most of the parts, but i don't know what frequency, how many windings and such would be needed for the coils. Also, if anyone knows of any other risks than the obvious burn hazards, I'd be thankful if you'd tell me before i go off and get killed trying to make this. Let's discuss! :D (Also, Skull Crucible is just about the most awesome name for anything ever).

Posted by huldumadurin 8 years ago

DIY Hatchback Subaru Legacy

Check out this DIY Hatchback I caught a few pictures of coming off the Bay Bridge in Oakland, CA. I think the guy driving was a woodworker, and needed a couple extra cubic feet to fit things like dressers and wardrobes.

Posted by ewilhelm 10 years ago

blimp coming soon! but need help

I have restarted the blimp project and it will be coming soon....i hope. i need to know how many cubic feet of helium does it take to lift 1 pound (16 ounces). also need to know if mylar will melt to. please respond

Posted by Sun Gear 10 years ago

blimp coming soon! but need help

I have restarted the blimp project and it will be coming soon....i hope. i need to know how many cubic feet of helium does it take to lift 1 pound (16 ounces). also need to know if mylar will melt to. please respond

Posted by Sun Gear 10 years ago

Contest:Save Houston, Recycle Ike

Calling all instructables utilizing millions of cubic yards of wood mulch.The city of Houston is sponsoring a nationwide contest to utilize the 5.6 million cubic yards of tree waste collected since Hurricane Ike hit the scene.The city is already considering a number of ways to use the waste, including for erosion control, boiler fuel and electric generation, but the mayor said he hopes others will come forward with large-scale possibilities.So get creative! Redesign the paradigm! Think long-term and quick to implement. All participants must submit all information on the "Participate" page by Midnight October 31, 2008Need a brain jolt to get the creative juices flowing?Whet your appetite with some simple ideas from the community:Reclaimed Wood TableSalvage Old Barn WoodExpandable Hydroponics System from JunkCheck out Make's coverage and the official site: Recycle Ike for more information.

Posted by scoochmaroo 9 years ago

How about a teeny tiny power supply??

I've seen some pretty good power supply projects on here. Here's a challenge: Make a 5 to 12 volt power supply that can fit into a 1 cubic inch space, of any dimensions, i.e. 1"x 1" x 1" or 1/2" x 2" x 1", etc, including any enclosure. It must put out at least 300ma sustained and must have a fairly smooth voltage regulation for use with other electronics (of course). It must have clear schematics without the use of special programs to view, i.e. it shouldn't be in an eagle format or rather can be viewed with paint, or any of the other picture viewers. It must be powered from the mains and NOT use a microcontroller or any custom chips. The smaller it is, the better, and less than 1 cubic inch is excellent. I've seen real genius on here. Is this genius ready to try this?

Posted by Pazzerz 9 years ago

Rf motion sensor connected to USB receiver

I am JUST getting into home builds and i want someone that can help me or make one for me.. I want a motion sensor device that can send a signal to a USB receiver.. I then want the usb receiver to inturpert the signal and do something .. - like open or toggle a program on that computer... ultimately it would be a cubical boss alert device.. when it detects motion it automatically flips my application! :) Any takers? Ryan

Posted by rmwilson 11 years ago

Smoking machine Specs, for hot smoky girl interactive sculpture ? (and ventilator)

Hi I want a smoke machine that pumps low cubic meters or that imitates this picture. It`s for a huge 123dmaker face sculpture Can i get this sort of effect? And can I get a ventilator that "inhales" the smoke  and makes it disapear?;=vg%2bScmVq&id;=153762409D14BE46E36C32C4027CD224EF895C32&thid;;=inhaling+smoke+girl&simid;=608020036307845272&selectedIndex;=2&ajaxhist;=0

Posted by DIAGONALLIS 10 months ago

Solar Air Con for animal shelter

I am thinking of moving to a warmer country ( SW France ) than England but I have a small pack of huskies that I would like to keep cool in the warmest weather. I was wondering if it is possible to use the solar energy available in abundance to provide an air cooling system for them. I realise that aircon normally requires a lot of electricity but I am only looking to keep a small space ( block built shelter of about maybe 7-800 cubic feet ) cool and hoped that this might be possible. Any ideas ?

Posted by ukpicker 7 years ago

Make supercapacitors from graphite in a DVD burner

The outline is that you can deposit graphite oxide (a cheap bulk material) onto a film of PET (the plastic used in Coke bottles), hit it with a commodity infra-red laser (such as the one in a $30 LightScribe DVD burner) and end up with a form of activated carbon material that can be used as the electrode in an electrolytic capacitor.  Add some aluminium foil, separator membrane and electrolyte and you've got cheap, robust energy storage.  The headline numbers are a few hundred milliFarads per cubic centimetre at a few volts, which works out to 1.36kWh per cubic metre of stacked capacitors.  It's still about 50 times less energy per volume than lead acid batteries, but you could store as much energy as your house will need overnight in the size of a garden shed or a set of bunk beds.  They charge/discharge in seconds and retain >95% capacity at 10,000 cycles so seem suitable for storage to even out intermittent energy generation from, for example, solar or wind power. I'm really thinking about cost here- unless I'm missing something fundamental it doesn't seem like producing these on a high volume roll-to-roll process would be excessively difficult, and the cycle life means the replacement time would be many years even in heavy usage.  Could you get sufficient kWh per dollar to make these a viable storage mechanism for home-scale renewables? There's a more informative article here.

Posted by PKM 6 years ago

Solar oven theory

When looking at various solar oven on instructables, they almost all use refective coating of some sort on the inside. That to me makes sense for the concentrators/parabolic/funnel ovens, etc. I am just wondering if the regular box ovens if it really makes as much difference or if the heating factor there is more so just the still air in the box being heated and not able to escape. I want to start making solar ovens to get an idea of how they work. I have a square piece of 1/4 inch glass, probably 4 ft by 3 ft. I thought about just digging a cubic hole in the ground and laying the glass over top.

Posted by avocadostains 3 years ago

Universal 3d printer cabinet

Hi everyone... just wanted to share with you a new campaign we launched live today on Kick Starter. Its a universal 3d printer cabinet we have been working on for a while... Its got almost 4 cubic feet of storage and can be accessed from a front door and the top of the cabinet...its ready to be customized with multiple knock out's to really get the results you want... We are producing in Black, White and solid Stainless Steel... I appreciate you taking a look and your time! Regards, Brian McLoughlin Maker Kase

Posted by bmc.loughlin 4 years ago

Battery charger help

As some of you may already know, I'm planning on building an electric car this summer. Its all planned out, but instead of using regular transformer based chargers I was wondering if someone could help me design a transistor based charger to reduce weight. Requirements 48 or 72 volts Needs to charge marine deep cycle batteries over night Needs to not have a transformer. Needs to be relatively small (under 1 cubic foot) Needs to be simple enough for me to build myself (I can do it if you can design it) Can anyone give me some links or some good schematics for this? Thanks

Posted by LinuxH4x0r 10 years ago

Small beach transport device ideas

Hello everybody I have quite a tall order for you my family is going to the beach in  a couple months and it is my custom to bring a fun and unique contraption along specifically a transportation based contraption I would normally bring a modified bicycle or something of that nature but since my entire family ( a family of four) has to fit into a ford explorer with all our stuff to last the week  the contraption must either be a board of some type or occupy a space of no more that 1.5 cubic feet so please let me know what you come up with and if I think of anything I will post it too  Thank you fidgety2

Posted by fidgety2 6 years ago

Really easy multi use desktop machine

I need a multi purpose machine that can fit in a one cubic foot area. I need it to do most or all of the following; 1.) Have a "3rd and 4th hand" 2.) Fit in a 1'x1' space 3.) Light 4.) A controlable .1-24 volts DC output 5.) Small Storage 6.) Large magnifier on a flexible mount. 7.) Built in ruler 8.) Wire reel holder Im Sorry for being so picky, but I need to somehow cram all of that in to a small space. Pics or drawing would be nice. But comments and ideas would be better. P.S. Pic isn't related to machine

Posted by ry25920 10 years ago

Warehouse House

Ever since i was 12, i've wanted to live in a warehouse, 1000+ square feet. my plan would be to build an apartment (myself) on the inside, out or 2x4s, etc. I would build the inner house to code, insulate and heat it (so i wouldnt have to heat a million cubic feet), and just do all the stuff you can only do when you live in a warehouse. like ride a go-kart between your bedroom and kitchen, and have a trampoline in your living room. Now that i'm approaching the age of "hey, you're gonna be 23 soon, you'd better start thinking about a house", this is becoming more and more appealing to me. Anyone have any input on procedures, policies, zoning regulations, bills, etc? If (when) i do it, i'll most assuredly post an 'ible.

Posted by falcotheimpaler 9 years ago

How to identify a metal ?

Hi ! Into a terrain near a very old volcano and a river, my brother found fragments of obsidian of various sizes and colors. Some of them are "glued" to metallic stones, and some others contain marbles of metals ... He also found a heavy metallic rocks (encrusted with obsidian) who reacts with magnet, and an other light one (without obsidian) who does not react with magnet. Do you know a mean to identify those metals ? (I Googled but found nothing very useful so far) Or do you have a clue of what it could be ? #1 is a metallic rock encrusted with obsidian. It must be iron because it's heavy, the rust is red, and it reacts to magnet. #2 and #3 is obsidian with marble of metal who reacts to magnet. #4 is an unknown (metallic ?) rock. It is light (150 grams for 200 cm3 - 0.33 pounds for 12 cubic inches), of the color of silicon (or the graphite of paper pen !), does not react to magnet but is (electric) conductor with resistance near 0 ohm.

Posted by chooseausername 10 years ago

Australians! Urgent help needed!

Hi everyone! I don't really know what category this should be put under, if anyone think it's in the wrong place feel free to move it. I am a guy from Sweden who are backpacking around the world and I am currently in Perth, Western Australia. I'm going abroad to Laos tomorrow and I will stay in south east Asia for about a month and then come back. My problem right now is that I have some luggage (extra clothes and camping gear) that I need to store somewhere during that time. I called a self storage company a couple of days ago from Coral Bay and booked a locker at their facility, however they forgot to mention that I needed to be there before five p.m. when the office closes even though I explicitly asked if I could come by later since I would arrive with the Greyhound bus. Does anyone know any fairly cheap (the lockers in the airport cost 8$ a day, and that is a bit too much) place  that is open at this time, or even someone in the area who could could spare some space for about 1/2 cubic meter of luggage until I come back? If so, please contact me asap either here or on 0405682652.

Posted by Jur 7 years ago

Led light & switch

Hi, I've purchased a wooden toy kitchen, for my daughter. I want to add a couple of special effects to it, for realism. There's one part I don't know exactly how to do and I don't know the correct terminology for the parts I need. So any advice would be greatly appreciated. basically, the pretend oven part of the kitchen, I'd like to add a push to make, illuminated switch to the panel that houses the pretend dials. I want this switch to be connected to a battery, hidden inside the play oven & upon pressing it, not only does the switch itself light up, it powers some red led lights. This is so when my daughter presses the button, it'll light up red inside, to give the impression it's hot, the oven has a Perspex panel, so the red light will be noticeable. I'm unsure how many led lights I'd need, it's probably 1 cubic foot in volume & doesn't need to be overly bright. So what type of push button switch, what types of LED & how many, what batteries and what other components would I need?   Sorry for the lack of knowledge & thanks for any advice.

Posted by dlee60 4 years ago

what do you think

Every one is going "green" these days and I myself am planning on going head on the opposite direction this is what I have, let me know what you think. I am building a GMC 3/4 ton 4wd. my first priority was what motor to use. so I asked around and a family friend said he had a 2 ton grain truck that has been sitting for years and was looking to get rid of it, he said it had a big block in it. so I took it because it was a big block. it is a 366 cubic inch big block tall deck (NOT A BORED OUT 350) I figured if its good enough for a two ton truck its good enough for my 3/4 ton. I also pulled out the transmission and it is the sm 465great transmission, and my dad gave me the transfer case its the np 205 the king of transfer cases. now I need better axels all i have are the factory 12 and 14 bolt. I am sure they will do but I am looking at getting the Rockwell 2 and 1/2 ton planetary gear set. you know the axels in the duce and a halves .I have a predicted fuel mileage of three to five miles to the gallon. but I could challenge anyone to try to out pull me because I have the gearing and the power

Posted by vince 09 9 years ago

My idea for the iRobot Challenge

Okay, I hope this is good :-D!Well, my idea is actually several ideas, but they all share the same theme:Chumby + iRobot's Create(And yes, I already have a Chumby)This might sound crazy, like adding speakers to an iPod, but it is defiantly possible.Since I don't have one, I can't say, for 100% sure, exactly how I'm going to make it work, but I have plenty of ideas. (I'll work backwards)The robot has 25 inputs. My last resort would to be to hook up the headphone jack to 2 of those inputs, and send signals by pulsing sound, similar to the way TV remotes pulse light. This is guaranteed to work, because Flash (which I'll be using in the project itself), can access the speaker. For robot-to-Chumby communication, there is the Microphone.Next up, is building this Sensor Package module that you can use with your Chumby. This would also work great, since it has 8 digital outputs, 8 digital inputs, and 12 motor drivers (which I could probably use as more outputs). However, I haven't found out yet if you can access this from flash, so it may become an issue. However, it seems more likely than the following:My first attempt is to tap into unused (in my setup) pins on the "Chumbilical", the main wire that connects the sensors to the main unit. This includes a USB port. Again, I am doubtful that Flash can access these, but I may be able to figure something out in Java or Phython.So I've hooked this up to the Chumby, now what? There are so many possibilities, because my new robot will now have various sensors from the Chumby, along with it's touch-screen display and WiFi.One could start with the "physical alarm clock", an alarm clock that you'd chase down to turn off. (As seen on ThinkGeek, it's "Clocky") Although, this is very much underusing it's capabilities. Next, of course, is the email alert system. When you're not on the computer, sometimes something external is a nice reminder :P In a workplace, lets assume someone gets an email every minute. This should be perfect timing for it to drive from cubical-to-cubical on every email. It would, however, be forced to rely on relative positioning.After the frivolous, this could be set up as a system where the Chumby would display images of me, streamed form a webcam, as I control the robot. Attached, would also be a webcam, streaming from the robot to my computer. (This was done with the Make: controller and a MacBook) (And yes, the Chumby has a HTTP server in it, and can support some webcams!)Heck! Why not have all three running at once :PI defiantly think the first 2 are not Instructable-worthy, but I wanted to give some other examples. The 3rd would be the one I do ;-) It would be much lest costly than the full-sized version, this being under $350. (I'm guessing that's about 1/3rd the cost?)Thanks for considering me as someone worthy of this "scholarship", I know I will use it over and over again if I end up getting it :D

Posted by zachninme 11 years ago

Living in a box, living in an expensive box...

Four Europeans are in the final stages of selection to be locked into a series of sealed boxes for a year and a half. They are competing for two of the six places in Mars500 - a full-scale simulation of a short-stay Mars mission (a year and a half each way, a month on the surface - don't get me started on how wasteful that is...). The Mars500 facility, which is located on the IBMP site in Moscow, comprises four sealed modules. The total interior volume is about 550 cubic metres. There are no windows. The walls in the living quarters have been covered with a wooden panelling to make them feel slightly less austere. Looking after the participants' needs will be a mission control-room sited just outside the containers. But the experiment's designers are determined to make the training exercise as realistic as possible, so they will introduce a time delay in communications after two months. Because it can take about 20 minutes for a message to travel from Mars to Earth, it will take this amount of time in the simulation also. Message delay The crew and their ground controllers will send text messages to each other and then have to wait for the replies. It means there can be no real-time conversations with friends and family - and, in moments of crisis, it will mean the crew will have to make crucial decisions themselves. I think the biggest test will be the social side - how will six humans, no matter how well-selected, deal with having nobody but each other for years on end, and being in each others' faces twenty-four hours a day? Could we end up looking at the first murder in space? BBC Story ESA article Institute for Biomedical Problems

Posted by Kiteman 8 years ago

[newsletter] Light Bulb Lamp, Predicting the Weather, Chocolate Speed of Light...

June 19, 2008 Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup1","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); } Welcome back! Want to put some insanely cool, lights on your bike? Then enter our Let It Glow! Contest. The prizes are super sweet and blinky, so enter before the contest closes this weekend! RoboGames 2008 is over for this year, but you can still enter our Robot Contest to win a trip to RoboGames 2009! Air fare, hotel, and entry fee are included!Winners have been announced for the Discover Green Science Fair for a Better Planet Contest. See who won, and bookmark some Earth-friendly summer projects! Check out these cool Instructables! DIY Vinyl Wall Art Liven up your apartment, without risking your deposit, by putting up some slick-looking ConTact paper designs to decorate your walls. posted by britsteiner on Jun 17, 2008 How To Measure the Speed of Light... Using Chocolate! Enjoy some gooey warm chocolate and learn some science at the same time! posted by bradpowers on Jun 13, 2008 Building Small Robots: Making One Cubic Inch Micro-Sumo Robots and Smaller With only cubic inch, you'll learn to be efficient in your robotic design. posted by mikey77 on Jun 12, 2008 How to make a piano keyboard Build piano keys from raw materials and make a piano you can truly call your own. posted by threesixesinarow on Jun 19, 2008 Steampunk Style Fan Cool off in neo-Victorian style with a custom built fan. posted by reluctant_paladin on Jun 13, 2008 Steel Centipede Turn that scrap metal and chain into a unique sculpture with nothing more than a welder and a bit of creativity. posted by Mikey D on Jun 15, 2008 LED matrix using shift registers Play with patterns of light and display messages on a custom LED matrix. posted by barney_1 on Jun 15, 2008 Predicting the Weather with Clouds Learn to understand what the sky is trying to tell you. posted by randofo on Jun 12, 2008 Instructables Robot -- Paper Model Print and cut out this template to make a papercraft robot of your very own! posted by =SMART= on Jun 13, 2008 Central Vacuum Retrofit Install a central vacuum system in an existing house to have quieter vacuuming and an external exhaust. posted by a.doovz on Jun 13, 2008 Rock Band Guitar Stand/Drum Support Tidy up your virtual rock star gear and keep your drums steady with this PVC setup. posted by evilbunnee on Jun 12, 2008 Win great books for your travel tips! Closes on June 29! Winners are up! Animating Multi Layered Engravings Take glowing etched acrylic to the next level with animated frames. posted by japala on Jun 18, 2008 10-minute electronic leather band Enhance a leather bracelet with a flashing light that can record and play back patterns. posted by craft-tech on Jun 14, 2008 The Lucid Dream Machine Control of your dreams with the power of flashing lights. posted by guyfrom7up on Jun 18, 2008 SketchUp, Inkscape, and Ponoko Laser Cutting Install this plugin and you'll have a free way to design in 3D and export your files to be laser cut! posted by flightsofideas on Jun 19, 2008 Light Bulb Lamp Put your dead bulbs to use by turning them into stylish oil lamps. Just be sure to put them in a safe place. posted by CYNICALifornia on Jun 14, 2008 Now go make something awesome, and I'll see you next week! - Eric Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup2","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); }

Posted by fungus amungus 10 years ago

Ice Art Alaska: San Francisco Art Institute Team

INTRODUCTION:In March 2008, a team of five graduate students from the San Francisco Art Institute (SFAI) are determined to participate in the World Ice Art Championships in Fairbanks, Alaska. Four sculptors will compete in the Multi-Block Classic event, which involves carving over 700 cubic feet of ice in under 132 hours. Additionally, we are bringing one archivist who will record and write about our experience. We seriously consider Ice Art as an opportunity to enhance our artistic knowledge and ingenuity, as well as to positively impact the communities involved.TEAM:Jesse Hensel, Team CaptainEric ReyesStephanie InagakiJesse WaltonLaura Rogers, ArchivistCONTEXTIce Art brings together communities from various countries -consistently from Canada, Norway, Russia, Japan, and China - and at all career levels including professional artists, students, and local residents. Each team has a different approach. Some will celebrate traditional craft while others will pursue edgy artistic expressions. Some will produce monumental forms while others will carve small-scale objects. For six long days, the SFAI team will work intensely together in the harsh Alaskan environment. During morning and evening meals they will reenergize and discuss different carving techniques and landscape traditions with other participants. This experience will undoubtedly benefit those in the competition in addition to educating and entertaining audiences worldwide.For general information about the competition visit: PARTNERS1. San Francisco Art Institute2. Make Magazine3. Morrow and Hensel Consulting4. Instructables

Posted by jesse.hensel 10 years ago

RoboGames Robot Contest Winners

Instructables and RoboGames are happy to announce the winners of the Robogames Robot Contest! With all of the fantastic robot entries out there, the task of creating your own robot army has just gotten a lot easier. We'd like to send a big "thank you" to everyone who took the time to share their knowledge and expertise with the rest of the world.Judging was done by David Calkins, Simone Davalos, Eric Wilhelm, Robin Lemieux, Robots Dreams, and Sb.And now, on with the winners! Second Prize The authors of these Instructables will each receive a Robot prize package including both Instructables Robot and RoboGames t-shirts, and a selection of robot-themed stickers. Category: Locomotion Pneumatic Animatronic Lego Snake Inchie BiPed robot V-3 The Manta Drive: proof-of-concept for an ROV propulsion system How to build the one motor walker! Category: Manipulators Mechanical Dry Erase Board How to build a simple robotic arm from Lego Mindstorms NXT? extendo hand Rubber band shooter / minifigure launcher Really, REALLY Easy USB Motor! Category: Brain Experimental Robot Platform Building Small Robots: Making One Cubic Inch Micro-Sumo Robots and Smaller RC truck robot conversion Ard-e: The robot with an Arduino as a brain Beginning LCDs Category: Sensors Ultrasonic Batgoggles DIY lego light sensor infrared ground/object sensor for robot navigation robot movement distance control fischertechnik Easter Egg Robot Category: Aesthetics WowWee's Elvis Alive to The Elivinator Project Wall-E Robot How to design and build a combat robot K'nex Programmable Automaton How To Build Your Own Instructables Robot Assistant Category: Reuse & Recycling Individuality Bot Build Your Own Butler Robot!!! - Tutorial,Photos, and Video How to Build a Robot - The BeetleBot v2 ( Revisited ) The Rock SOCBOT - the next generation vibrobot First PrizeThe author of this Instructable will receive a RoboPhilo Walking Android kit! Plus the Robot prize package including both the Instructables Robot and RoboGames t-shirts, and a selection of robot-themed stickers. Wall-E by 4mem8 Grand Prize The author of this Instructables will receive a trip to the June 2009 RoboGames in San Francisco, CA! Includes airfare for one from anywhere within the continental US, 4 nights in a hotel near the event, and VIP access/entry fees. Experimental Robot Platform by societyofrobots

Posted by fungus amungus 10 years ago

"Ride" by Michael Cooper - My Favorite Thing From the Maker Faire

This was, by far, my favorite thing at the 2008 Maker Faire. From Make's Description:Ride is a custom single rider helicopter with eight engines conceived & created by sculptor, Michael Cooper. It looks like more like a time machine invented by Dr. Seuss for George Jetson than anything you've seen in the air (or on land) recently.Michael Cooper is a sculptor who combines wood, metal, kinetics and mechanics with a twisted imagination resulting in beautiful, unique works of art that roll, spin, hop, contort and make people laugh while simultaneously scratching their heads. After 34 years as an art instructor at Foothill and DeAnza Colleges, he has now "retired" to his studio in Sebastopol where he spends his days devoted to sculpting, inventing and pushing the boundaries of form and function with a heavy does of humor.I know the pictures don't do it justice, and it's really hard to see everything, but take a long look and answer this question before you continue: Do you think it does/could fly? (Scroll down below the line and look at the pictures.)... did you look at the pictures first?There are so many reasons why it can't fly that I won't bother to discuss them here. However, the truly fascinating thing I liked so much was standing around Ride and listening to the conversations, and particularly watching its creator stage-manage the discussion. Lots of people wanted to discuss why they thought it could or couldn't fly - remember that this was the Maker Faire, so lots people here were builders or tinkerers (or at least thought of themselves as such). There were half-hour long heated debates about the tiniest of minutiae -- fuel line diameters and spiral exhaust ports, for example.Periodically, someone would gain the courage to think about the system as a whole and would approach the creator to ask, "So it flies, right?" He'd answer truthfully enough by saying, "Well, it's not done yet," and then launch into a detail, like the difficulty in synchronizing 8 engines; this would get the whole group rolling again. Later Saturday evening, when most of the kids had gone home and everyone else was outside listening to a band, a group of particularly crotchety old tinkerer-types were showing off their smarts and trying to outwit each other. After one onlooker had finished with his unnecessarily loud pronouncement of "based on my extensive experience building 1/6th-scale steam locomotive engines, I absolutely sure it can fly," another of the group tentatively approached the creator, and asked the inevitable question.Michael Cooper took his cue, dodged, and redirected into a discussion of how the transmission linking the 8 engines to the propellor was open, and the first time he ran it, he was probably going to get covered in grease. I burst out laughing.After they were all rolling again on how many cubic feet of compressed air the vehicle should optimally carry for its four pneumatic lifter feet, I quietly asked Michael how many people "got it" and how many people asked if it could fly. He confided that I was very much in the minority. Further, he got a big kick out of removing his name tag, and listening in to the can-it-fly conversations, too.I really hope I get a change one day to work with Michael Cooper to design and build a gorgeous Ride-like vehicle for me, so I get the chance to answer the question, "So, does it really fly?"

Posted by ewilhelm 10 years ago

Instructables Book Contest Winners

Instructables is happy to announce the winners of the Book Contest. All of these Instructables will receive a mention in the Best of Instructables Volume 1 and the authors will receive a copy of the book when it comes out this fall.Some of the Instructables here have also been selected by O'Reilly editors to be fully reproduced in the book as well.Congratulations to all the winners! Thank you for making great Instructables that inspire everyone else.InstructableAuthorLED ThrowiesQ-BranchInvisible Book ShelfdorxincandelandLaser Flashlight Hack!!KipkayMintyBoost! - Small battery-powered USB chargerladyadaDIY Compact Survival KitledzeppieHow to make a cardboard costume helmetHonusturn signal biking jacketleahbuechleyAudio Visual Art....FOTC Stylescooter76Wall-E Robot4mem8Paper WallettheRIAAScreen Printing: Cheap, Dirty, and At Hometracy_the_astonishingMunny Speakersfungus amungusKnex Heavy CannonI_am_CanadianHow to Make Playdough (Play-doh)canidaLED Chess SetTetranitrateSew your own Instructables Robot Plushie!jessyratfinkDIY Vinyl Wall ArtbritsteinerBluetooth Handgun Handset for your iPhone: iGiveUpManaEnergyPotionEasy to Build Desk Top 3 Axis CNC Milling MachineTom McWireBuild Your Own Butler Robot!!! - Tutorial,Photos, and VideoErobotsHow to build a 96-Volt Electric MotorcycleKentucky-bumHow To: Make Bath BombsSoapyHollowSteampunk Dystopian Sniper Rifle (Mercury Bow)gmjhoweSave $200 in 2 minutes and have the worlds best writing penkingantConcrete Lightbulb Wall HookwhamodyneLight Bulb LampbumpusLightbulb "green"houseLinuxH4x0rInstructables Robot -- Paper Model=SMART=How to Build a Robot - The BeetleBot v2 ( Revisited )robomaniacWallet made from a computer keyboardzieakhow to add EL wire to a coat or other garmentenlightedGandhi: 17' Tall Cardboard AvatardelappeTure Trigger, 10 Round, Auto-Loading, Knex Concept Rifle, by bannana inventorbannana inventorHow to build your own Jet EnginerusswmooreShake it like a Tic-Tac!MrMunkiCyber/Steampunk Futuresque Sci-Fi Hand GungmjhoweHow to Make a Marshmallow Gun or Marshmallow ShooterewilhelmHow to build a 72Volt electric motorcycleStrykerFriends Are Easy To MakecuteaznprincesssBuilding Small Robots: Making One Cubic Inch Micro-Sumo Robots and Smallermikey77Portable 12V Air Conditioner --Cheap and easy!CameronSSHow to Make a TRON Style Lamp: The MADYLIGHTGreg MadisonGiant MatchTetranitrateMagnetic Rubik's Dice CubeburzvingionHow to build a wood fired hot tubveloboyIron Man HelmetpmaggotHome-made Sun Jarcre8torGrow Your Own Bioluminescent Algae ScaryBunnyManConstruction of Two Portuguese Style Dinghies (Small Boats)rook999Uni-Directional WIFI Range Extendertm36usa"1UP Mushroom" Mushroom Burger!momo!Open Any PadlockTetranitrateCoilgun Handgunrwilsford07Electroforming an Iris Seed PodMaggieJs100 Ways to Reduce Your ImpactBrennn10Lego USB StickianhamptonSolar Powered Trikedpearce1How to Make a Three Axis CNC Machine (Cheaply and Easily)Stuart.McfarlanAirgun with eXplosive air-Release ValvechluaidChapStick LED FlashlightBCatAwesome led cubeAlexTheGreatBarbie Doll Electric Chair Science Fair Project!jessyratfinkDIY 3D ControllerkylemcdonaldThe Stirling Engine, absorb energy from candles, coffee, and more!thecheatscalcBuild a World's Smallest Electronic Shocker!PlasmanaSimulated woodgrain for metal boxesamz-fxHow to Grow Pineappleswoofboy111Creating a 3D effect with image editing software (GIMP or Photoshop)Andrew546S.P.R.E.E. (Solar Photovoltaic Renewable Electron Encapsulator), a Compact, Durable, and Portable Solar Energy GeneratorcharlitronHow to get a Tshirt for GoodHartRocketScientist2015Grow a square watermelonwatermelonBuild a 4 Color T-Shirt Printing PressProgfellowElectromagnetic FloaterJ_HodgieThe accidental pocket jet engine...killerjackalopeDigital Picture Framemicahdear

Posted by fungus amungus 9 years ago

Question on using a Peltier/TEC device for air temperature control - Help please.

I want to have some control over the temperature inside the Orchidium I'm designing and I thought it might be cool :) to use a Peltier Device (device aka module) (Peltier aka TEC or Thermoelectric Cooler). I find I need a lot of help! (Please!) Alright, this isn't a completed Instructable, it's a plea for help, and maybe if the subjects lie in some of your fields of knowledge then we can all enjoy and learn from it. So, the Orchidium I'm designing is an acrylic case 24"W x 18"D x 30"High. It's to grow species orchids indoors in a microclimate, with LED grow lights, proper humidity, air movement and temperature control. (Of course, other critters would like the case, too: poison dart frogs, newts, carniverous plants, etc.. But I'm going to call it the Orchidium.) I've got it all pretty well planned out so that it can be built for a very reasonable price (yes, including the LEDs) and still be aesthetically pleasing and real purdy, too. All planned out EXCEPT FOR THE TEMPERATURE CONTROL. I was looking for some way to cool my case and I stumbled across Peltier devices in eBay. They are CHEAP, costing about $5 or more, depending on the Wattage, etc. The eBay sellers intimated that all you have to do is plug them in and the device gets ice cold. Later, with diligent web-study I learned that actually ONE SIDE of the peltier gets cold, while the other side gets hot. Also, you MUST attach a heat sink and fan to both (?) sides of the peltier. Also, that these devices are not ready to be plugged in; you must attach a DC power supply to them. Oh, another trick that these miraculous devices do is reverse their hot & cold sides when you reverse the polarity of their juice. Ideally, I would like a Peltier device with heatsinks, fans, a thermostat and a DC wall transformer attached... the Peltier/heatsinks/fans would measure about 2" x 2" x 6" and would be mounted in the sidewall of the Orchidium. When the temperature is 65-85F degrees the orchids are happy and the device is Off. But when the thermostat senses the internal temp going over 85F it turns on the Peltier, cold side inside, and so the inside of the case doesn't go up to 90-95F like mine does now; it cools the case a little. Conversely, for someone with chilly orchids or sneezing newts the thermostat would switch the Peltier to hot-side-in to heat the Orchidium a bit. The retail cost for us to buy a Peltier device, 2 heatsinks w/fans and a DC transformer is cheap... roughly $30. The thermostat might be cheap, but I don't know enough about what's needed. If it's too expensive then the Orchidium can do without it. I was hoping I could find an off-the-shelf Orchidium cooler/heater. No such luck. These miraculous Peltier devices are still practically undiscovered -- relatively speaking. People want to use them to cool their computer chips but are hampered by condensation; my orchids welcome condensation. Pathetically, it seems the most common use for Peltiers now is to cool/heat the little boxes on your car seat... they plug into your cigarette lighter and keep your 6-pack cold. Come on! You folks at Instructables can surely help me figure out how to best make an Orchidium cooler with this barely-discovered and poorly-utilized device. I started out a few weeks ago writing to many of the Peltier manufacturers around the world in hopes they might help me in choosing which of their modules I might purchase for my Orchidium. None of them was any help. They wanted to know how many million Orchidiums I planned per year. They told me my basic plan was hopeless or inefficient cost-wise. A Swedish company wanted $800. An American company wanted $500. Some other company wanted $5,000 to $8,000. I wrote back and said I could get a Peltier on eBay for five bucks. The Swedes snottily claimed that their Peltiers were very high quality. No. No way is any svensker Peltier $795 better than ANY other Peltier in the known universe. They both get cold and grow ice crystals on one side. I just need to cool the case A LITTLE BIT, like from 90 to 80 degrees Fahrenheit. I am not trying to make a refrigerator or freezer. The case (Orchidium) is large, at about 7.5 cubic feet, and there is practically no insulation. Acrylic provides a little insulation, that's all. The temp of the interior of the case is derived from the ambient room temperature of your house... and the lights... which is why I designed it with LEDs. There is a constantly-operating muffin fan inside the case to provide air movement for the plants, but it does not provide any evaporative cooling since it's a closed case. So, first off what size Peltier do you recommend... do you think a 40 Watt would be enough, or what? Next, the placement. I envision the Peltier device mounted vertically through a hole in the side of the case. It might be a plan to mount it in the ceiling, but remember that the LEDs take up most of the ceiling. Next, the heatsinks. I confess I'm not totally clear on this, but I "think" that 2 heatsinks-with-fans may be needed, with one sticking out the outside and the other inside the case. I went ahead and got 2 heatsink/fans from Newegg for supercheap ($1 after rebate), but they aren't really what I want. They're actually shaped to fit some AMD chip. What I think I need is a copper heatsink with a flat bottom a little bigger than the Peltier, and fins... and a heatsink fan attached... and some way to attach it to the Peltier, and through the case to the other heatsink. See? Simple... well it should be but I can find nothing. Next, the power supply. I know it has to be DC, but I don't know which brick to get. I did find a bunch of DC or AC Wall Transformers for sale at alltronics... around $10 or so. All that stuff would be enough... at least to test the cooling power. But if we want to go whole hog then the icing on the cake would be thermostatic control of the Peltier. Well, I throw that out in case one of you is sharp in that field.

Posted by Knuten 10 years ago

Top 50 2008: Instructables

Yesterday we looked at the Top 50 commenters for 2008 and today we'll be looking at the numbers for the top 50 Instructables of 2008. Since there's no one way of declaring a list of Instructables, we created three top 50 lists. These cover Instructables in order of rating, pageviews, and comments. Instructables on these lists were all published in 2008.Let's go to the graphs and charts!Top 50 Instructables: Pageviews   Instructable Views 1   Body-Mod: Elf Ears 347738 2   Use your laptop as an Xbox/Xbox 360 "Wireless Adapter" on Windows XP/Vista, and Mac OSX 220780 3   Fix the Red Ring of Death! (without towels!) 177285 4   Laser cutter, start slicing stuff for under 50 dollars 159647 5   Run Backups on any Wii Without a Modchip 159408 6   How to build a 72Volt electric motorcycle 159261 7   How to make out 145713 8   Inverted Bookshelf 137198 9   Munny Speakers 124736 10   Awesome led cube 118293 11   Firefox Pranks! 117449 12   How to make an Iron Man Arc Reactor 116481 13   How to French Kiss 115958 14   How To: Make Bath Bombs 108287 15   Gift Ideas 107914 16   DIY USB "Hard Drive" 96588 17   Safely Shaving Your Pubic Hair 96144 18   WinXP Overhaul Guide: How to make it look like Vista, run like lightning, and stay productive, fast & smooth 94980 19   Laser Tattoo 94705 20   DIY Vinyl Wall Art 92752 21   How to refill a "disposable" Brita brand water pitcher filter with activated carbon. 89724 22   Make your own Roll-Up Keyboard 89558 23   Hidden USB Storage 86430 24   how to add EL wire to a coat or other garment 84340 25   Build a 60 Watt Solar Panel 82286 26   Grow a square watermelon 82275 27   LeGummies brick shaped gummy candies 81368 28   USB 80875 29   How to remove most of the seeds when cutting up a watermelon 80822 30   How to Make a TRON Style Lamp: The MADYLIGHT 80281 31   LED Cube 4x4x4 78936 32   Covert Spy Sunglasses 78633 33   Build a water mortar 77090 34   Super Nightvision Headset Hack! 76634 35   A better laptop stand for bed 76101 36   Amazing plasma globe tricks that you never knew before!!! 74842 37   How to get a Free Itunes Account (No Credit Card Needed) 74490 38   Make an iPod Video Projector 74026 39   Homemade Gifts 73478 40   Lasers 73242 41   Remote shutter trigger for Digital Cameras 72911 42   Ergonomic Laptop Stand Made From a Coat Hanger 72321 43   MAKE A HIGH VOLTAGE SUPPLY IN 5 MINUTES 71744 44   Protect Your Home with Laserbeams! 71387 45   Iron Man Helmet 71358 46   Get Big Money for Dead Batteries 70261 47   How to Put on a Condom 69805 48   How to make an Iron Man Mask 69617 49   How to build a 96-Volt Electric Motorcycle 68924 50   Nintendo Lunchbox 68164 Top 50 Instructables: Ratings   Instructable Rating 1   Build A Plasma Speaker 4.64 2   Build A Net Gun 4.62 3   Wall-E Robot 4.60 4   Sew your own Instructables Robot Plushie! 4.60 5   How to Make a Portable Game System 4.54 6   Build Your Own Butler Robot!!! - Tutorial,Photos, and Video 4.54 7   Electromagnetic Floater 4.52 8   LED Cube 4x4x4 4.50 9   LeGummies brick shaped gummy candies 4.49 10   DIY Vinyl Wall Art 4.49 11   5-minute Chocolate Cake 4.48 12   When a Phillips is not a Phillips! 4.48 13   Airgun with eXplosive air-Release Valve 4.47 14   How to Build a Robot - The BeetleBot v2 ( Revisited ) 4.45 15   How to Start a Business 4.45 16   Gandhi: 17' Tall Cardboard Avatar 4.44 17   turn signal biking jacket 4.44 18   Hidden USB Storage 4.44 19   Cyber/Steampunk Futuresque Sci-Fi Hand Gun 4.43 20   LED Chess Set 4.41 21   Build your own Electric Car! 4.41 22   LCS-1M - A Full-Featured, Low-Cost Hobby Oscilloscope 4.40 23   Build a World's Smallest Electronic Shocker! 4.39 24   Lego USB Stick 4.38 25   MAKE A PILLAR WITH A DECORATIVE CAPITOL AND BASE 4.38 26   EGG FLOWER VASE 4.38 27   Aliens Powerloader Halloween Costume 4.38 28   Munny Speakers 4.37 29   Giant 100mm LED 4.37 30   Coilgun Handgun 4.37 31   How to Thank Instructables 4.36 32   Guitar Tube Amp 4.36 33   How to get a Tshirt for GoodHart 4.34 34   Creepy Cobweb Shooter! 4.34 35   Grow Your Own Bioluminescent Algae 4.32 36   How to make a Portal Gun 4.31 37   how to add EL wire to a coat or other garment 4.30 38   Duct Tape Messenger Bag + Hardware 4.30 39   Firearm Safety: The "do's" and "don'ts" of enjoying guns safely. 4.29 40   The Stirling Engine, absorb energy from candles, coffee, and more! 4.29 41   Recycle Old Light Bulb 4.28 42   USB Batman Spotlight 4.28 43   Coffee table upgrade! 4.27 44   Steampunk Dystopian Sniper Rifle (Mercury Bow) 4.27 45   Building Small Robots: Making One Cubic Inch Micro-Sumo Robots and Smaller 4.27 46   How to grow flowers on a military base in Iraq 4.26 47   How to make your own LED lightbulbs 4.26 48   Iron Man Helmet 4.25 49   Cardboard/Fiberglass Halo 3 inspired Master Chief Costume 4.25 50   Build Halo Armor 4.25 Top 50 Instructables: Comments   Instructable Comments 1   Build a World's Smallest Electronic Shocker! 812 2   Knex Heavy Cannon 645 3   Awesome led cube 637 4   Simple Xbox 360 Rapid Fire Mod 591 5   Build A Plasma Speaker 494 6   DD-27 V2.75 compact AST rifle 454 7   WinXP Overhaul Guide: How to make it look like Vista, run like lightning, and stay productive, fast & smooth 453 8   The accidental pocket jet engine... 427 9   Scavenge free electronics, food, and help the environment 400 10   How to make your PSP "Better" or how to have more fun on a Sony PSP 379 11   Laser Tattoo 376 12   Amazing plasma globe tricks that you never knew before!!! 376 13   DSman195276's sidearm --updated-- v1.5 is here! 371 14   MAKE A HIGH VOLTAGE SUPPLY IN 5 MINUTES 363 15   Wall-E Robot 352 16   Knex Heavy Cannon v5 - Handheld 342 17   Fix the Red Ring of Death! (without towels!) 341 18   How to Build a Time Machine (Vortex Distortion Space and Time Dilating Device) 340 19   Knex Heavy Cannon v2 - Mini 339 20   How to get a Tshirt for GoodHart 338 21   Run Backups on any Wii Without a Modchip 336 22   Make A Water Leyden Jar 331 23   Park 52 knex sniper 327 24   Build a simple Marx Generator 323 25   Knex Guinea Pig Trap 318 26   TRUELY semi-auto knex gun 315 27   L96 308 28   How to Build a Knife 307 29   Pineapplebob's Sniper Rifle 306 30   True Trigger, 10 Round, Auto-Loading, Knex Concept Rifle 299 31   Fire Shaving 290 32   DJ Radio's knex SPEC-9 sniper rifle 285 33   How to UPGRADE from Vista to Windows XP on an Acer laptop 283 34   How to dodge a draft 279 35   Protect Your Home with Laserbeams! 279 36   Hidden USB Storage 277 37   Knex Compact AST Pistol 276 38   Cyber/Steampunk Futuresque Sci-Fi Hand Gun 276 39   Steampunk Dystopian Sniper Rifle (Mercury Bow) 275 40   Pocket sized survival kit 274 41   Knex Pistol "TDS" With Simple Slide Action *Updated as of 8/26/08* 271 42   Use your laptop as an Xbox/Xbox 360 "Wireless Adapter" on Windows XP/Vista, and Mac OSX 269 43   Body-Mod: Elf Ears 266 44   Knex M4 Carbine (True Trigger) 257 45   How to make a Portal Gun 255 46   DSman195276's sniper rifle 254 47   Reaper Crossbow 254 48   fully automatic knex gun (UPDATED) 252 49   Build your own computer 252 50   LeGummies brick shaped gummy candies 252

Posted by fungus amungus 9 years ago

Technology Makes Cheap Drinking Water from Air

INTRODUCTION:   How can we best apply basic technology to help the underprivileged and/or disaster-hit countries like Haiti? Daily hygiene and nourishment are among the top needs for disaster ridden regions!  Simply put, no water means no hygiene. The Romans understood that over two millennia ago and created their complexly beautiful aqueduct networks for handling both fresh and wastewater! Other ingenious water systems like “air wells” have been found in the city of Theodosia (cf: discovered in 1900 by Zibold, see Zibold’s Collectors/Dehumidifiers) dating back to Greco-Roman times during the Byzantine Empire. These were strictly passive systems that naturally dehumidified air, collecting its potable water in underground basins. All air, even in relatively dry desert regions, will precipitate or release its natural water content (initially in the form of vapor) through condensation when it hits its dew-point temperature and below. That means you “chill” it to an appropriate level that is anywhere from 5F to 50F below its current air temperature, depending upon how much water content (relative humidity) it has locally absorbed. The condensation of the water vapor releases its internal latent heat (reheating the cooled air) which must be constantly dissipated (absorbed by something) in order for water formation to steadily continue. So how do we dissipate this resultant vapor-heat and chill our air without any infrastructure or electricity, in an underprivileged or disaster-ridden region? We simply bury a long cast-iron or any metallic drain-pipe sufficiently underground where the temperature of the earth is naturally held to a constant at around 45F to 55F. That’s our “free” chiller gift from nature. One end of the pipe, Figure-1,  sticks out of the ground to suck-in local outside hot air, and the other end dumps cooled dry air and water into an underground cistern where it gets collected and is piped to the surface to both exhaust the cooled dry air and connect to a water pump. We need a hand operated water pump to lift up the water above ground, and we need an electric fan to constantly pump air through the ground-chilled piping system. We can even force the cooled piped air to exhaust into a tent-like structure where it provides air conditioning as an added bonus, but this adds the penalty of both power and the increased fan size necessary to drive our required airflow further into an enclosure! While this concept is not “passive” (requiring electricity to work) like those clever Byzantine air-wells, it will produce much more potable water and within a smaller volume than those elegantly passive historic devices. The electricity for our fan power requirements can be produced by any one of four ways using either “active” or “passive” techniques: 1) An active playground or bike-pedaling-person or oxen-driven mechanism-generator, 2) A passive windmill generator, 3) A passive solar energy collection system that directly generates electricity, or 4) A passive thermo-electric system that directly generates electricity using the Peltier effect, operating solely on temperature differences between the cell’s top and bottom surface (we jury-rig the cool pipe and hot ambient air to contact separate sides of the cell). Depending upon how much water is needed, the required air volume plus pipe length and diameter, together with the fan will be sized accordingly. We can also configure groups of parallel fan-driven air pipes that are radially fed into the cistern. The sizing of this underground network depends upon the ambient air’s local average temperature and relative humidity (how much water gets absorbed into the air) plus buried pipe depth and effective underground temperatures achieved. The basic concept is one where we “wring” water from air at some given humidity content. The higher its relative humidity the more water is recovered from the air. The air-wringing process simply chills the air as it scrubs along the cooled internal pipe surface until it starts to rain inside the pipe from condensation onto its surface. The condensation is like the dew that forms on car windows, grass or any cooled surface in the early morning, before the sun comes out and evaporates the dew back into the heating air. A further bonus is that our dew-formed water is naturally distilled and very clean. It is potable water ready to drink without the need for additional sterilizing agents. Of course, we must make sure that the interior piping and cistern network is biologically cleansed before burying it underground. The hand pump with its 10 to 15 foot extended piping to reach the underground cistern must also be cleansed. The beauty of this constantly replenishable water supply is its convenient underground installation anywhere! After the in-ground installation, we have a virtual, partially passive, no moving parts, non-breakdown system containing above ground total access to all moving parts that could breakdown, namely the water pump and electric fan. Also, it is easily maintained, with few moving parts (water hand-pump and electric fan) and basically lacking any technical complexity which makes it ideal for technologically backward regions. The example below uses a relatively small industrial fan moving air at 1500 CFM (Cubic Feet per Minute) with a DC motor rated at 1kW. This fan together with our underground piping system will conservatively generate 12 GPH (Gallons Per Hour) of potable drinking water without need for any purification chemistry. Based on an average electrical cost of 14-cents per kWh (kilo-Watt hour), the typical commercial distillation of one gallon of drinking water costs roughly 35-cents as compared to our cost of only 1.2-cents. Furthermore, if we decide to go green and use solar energy for generating our water, it would effectively cost us nothing beyond the initial installation! USING A PSYCHROMETRIC CHART TO SIZE OUR WATER SUPPLY: The following gets a little technical and is only provided for those die-hards who are truly interested in how the science works. Those non-technically schooled may skip this part and not miss the basic concept. Figure-2 shows a Psychrometric Chart for air. This chart summarizes some of the basic thermodynamic properties of air throughout its typical range of operating temperature. The chart uses six basic air properties that defines the physical chemistry of water evaporation into air:  (1) the enthalpy or total energy contained within a unit of air which is a combination of its internal and external energy, expressed as the amount of BTU-energy per unit mass of reference dry-air, (2) the specific volume or the ratio of a unit volume of local air to its mass of reference dry-air, (3) the humidity ratio or the amount (mass) of moisture in a local unit of air divided by its reference mass of dry-air, (4) the percent relative humidity per unit of local air, or the mass ratio (expressed in percentage form) of the partial pressure of water vapor in the air-water mixture to the saturated vapor pressure of water at those conditions (the relative humidity depends not only on air temperature but also on the pressure of the system of interest),  (5) the dry-bulb temperature or the locally measured air temperature, and (6) the wet-bulb temperature or saturation temperature which is the local air temperature experienced during constant water evaporation (a wet-bulb thermometer is typically used:   a thermometer that measures resultant temperature while wrapped in a water wet-gauze and spun to generate local air movement and max-evaporation)  1.0   The Process and A Sample Calculation Our Psychrometric Chart uses six thermodynamic properties that help to determine the amount of water available for extraction from the local ambient air as a function of its temperature, pressure and relative humidity.  Let’s assume the following local ambient conditions for the region we plan to construct our water system at:  (1) Typical daily air temperature Td = 106F and one atmosphere pressure assumed at sea-level, (2) Relative Humidity, RH = 55%, and (3) Typical underground temperature down at six feet is measured at Tu=55F (at 12ft. it drops to ~45F). This yields the following calculated results for obtaining a steady-state supply (changes at night) of water to fill the cistern:      1)      In our example, the “local” air (dry-bulb) temperature is Td=106F, at a relative humidity of RH= 55%.  Fig-2 indicates that the resultant Humidity Ratio is HR= 0.0253 Lbs-water/Lb-Dry-Air (intersection of Td=106F line and RH=55% line, then horizontal to HR value).  We then determine the “gulp” of air volume containing the HR Lbs-water which corresponds to the point of intersection of Td and RH. Interpolating on specific volume “mv” yields mv=14.7 ft3/Lb-Dry-Air (this value sets the optimum unit airflow for our given ambient conditions, and creates a ballpark pipe length to diameter ratio needed later). It represents the basic unit of air volume that will enter our underground pipe per given time, and ultimately defines the size of our fan and piping network. For increased water creation, multiples of this unit volume will scale up the additional amounts of water that can be collected. 2)      As the inlet air cools down to a temperature of Tu=55F, from contact with the relatively cold underground pipe, we follow the constant enthalpy line (red upward left-diagonal) from the intersection of Td and RH to its saturated air temperature condition of Ts= ~88F, which is its dew-point temperature where the corresponding local RH=100%.  At this temperature or under, the air precipitates and releases its moisture content, resulting in water condensation onto the pipe walls.  Since our air will chill to a final pipe temperature of Tu=~55F, we follow the RH=100% saturated curve (green) down to yield an HR=~0.009 Lbs-water/Lb-Dry-Air. This is how much water is left in the air when it gets to 55F.  Therefore for every pound of local outside air that enters the pipe, mw=0.0253 – 0.009 = 0.0163 pounds of absolute pure, distilled potable water precipitates onto the inside pipe wall (per pound of dry air that is cooled and dehydrated) to gravity-flow out the pipe exit and into the cistern. 3)      We now convert pounds of air per unit time into a unitized volumetric airflow that yields gallons of hygienically pure potable water production per unit time. For every Va=100 ft3 of local volumetric air movement per minute (CFM) through the pipe, which translates into ma=Va/mv= 100/14.7 = 6.8 lbs. of dry air per minute or 6.8 * 60 = 408 lbs. per hour (PPH), to yield a water-flow of mwf=ma * mw = 408 * 0.0163 = 6.65 PPH or 6.65/8.345 = 0.8 GPH of water.  An industrial fan rated at 1kW DC will typically move 1500 CFM at a pressure of 8-iwc, to continuously produce 15 * 0.8 = 12 GPH of pristine potable water. 4)      Not shown here are the design details of sizing our pipe, fan and solar collection system for electric power requirements using heat transfer principles coupled with a thermodynamic heat balance, and aerodynamic fan performance assessment. These details help to size the electric power generation requirements plus margin used to properly size a solar collector containing further margins for overcast days. The engineering involved here is straight forward but beyond the scope of the current project.

Posted by RT-101 6 years ago