How to test the power output on a wind turbine?

I'm on a team prototyping a water filtration system powered by a Savonius wind turbine; the energy from the spinning turbine is mechanically transferred to a reverse osmosis filter/pump setup. We're doing tests of various blade configurations and are trying to determine the power output by hooking up a small DC motor (1-3V, 5000+ RPM) to the shaft. We're seeing only mW outputs though and were expecting something significantly larger. How do we pick a motor for the job? Do we need to match the RPMs of the motor to the expected RPMs of the shaft (~150)? Any other ideas for testing power? Thanks for any help!

Posted by moisture 9 years ago


I wnt to build a directional speaker that can send more than 25mghz to my neighbors dog?

I have two german shepards next door who are driving me crazy with their barking all day and all night

Asked by 9 years ago


Researching DIY Projects, Cultures and Communities

Sorry for the double post, but there are only a few days left before we close the survey, so I thought I'd post it to a different forum.We are researchers at Carnegie Mellon University, conducting a brief 10 min survey to further our understanding of DIY projects and communities. In the name of science (and for fun) please complete the survey located at the website below:http://tinyurl.com/DIYCommunitiesWe hope to share the collected data at the end of the study. We thank you for your time and effort.Stacey Kuznetsovstace@cs.cmu.eduEric Paulospaulos@cs.cmu.edu

Posted by staceyk 9 years ago


Slideshow Delay

When I edit a slide show it takes about a day to show the new pictures. Is this normal?

Posted by Wafflicious 9 years ago



Resistance is Futile

Do you agree with the saying, Resistance is Futile? It can be applied in anything, politics, electronics, etc.

Posted by starwing123 9 years ago


gyroscopic underwater camera stabalisation

Hi does anyone know if it possible to create a stabilisation platform to make a video camera point directly down all the time underwater. the ultimate goal is to attach one to the front of a Diver Propulsion Vehicle to map small sections of the sea floor. at the moment we planning to just have a guy being towed on a rope behind the main diver keeping the camera down Thanks for any advise Tom

Posted by tawcnysc 9 years ago



Can Someone Explain The Game 'Conkers'

I've seen variants of the game on different UK shows, but never knew how to properly play it. Could someone explain to me how its played, rules and such? An instructable would be much admired. :D

Posted by bumpus 9 years ago


How should I protect my eyes when working with a laser?

I want to built a laser cutter and have bought a 7W laser for it. How should I protect my eyes? What is important in building it to make it safe / have no risk left to hurt my eyes...

Asked by macmoritz 9 years ago


Regulated pwr supply using one pwr source to supply 3 lasers w/ diff amounts of V and adjstable mA (info in Details)?

I am working on a multicolored laser unit combining 3 different colored lasers (violet, red, and green) and i would like it so that they can all be supplied with power from one source (such as a AC-DC wall transformer). But each one runs at a different amount of mA's and Volts. I cannot figure out how to get the exact voltages and mA's that i need to run each laser from one power source. here is what the circuit needs to do: --- Use one power source to simultaneously supply 3 lasers with constant voltage and adjustable (using a POT) current. --- Be able to continue to supply constant voltage and current to the other lasers if one is turned off (i dont want the mA or volts to suddenly rise and blow one laser if i turn the other off). --- Use 3 seperate POTs be able to individually adjust the mA delivered to each laser (all of them will run at max mA and if i want to turn down the green i would up the resistance of one of the POT's to reduce the mA flow to the green laser) the 3 lasers that i will be running each have different power specs. below is the max power that i will want to run each laser at. the voltage delivered to each laser this circuit must always remain CONSTANT. the mA's delivered to each laser must be able to be LOWERED from the below specs using a potentiometer or variable resistor. 6V 120mA 4.5V 420mA 3V 340mA If anyone could figure out a circuit or design that delivered these 3 voltages and the same or similar ampages to the lasers from lets say a 12v 1amp power source (it could be more or less as long as i can buy it online), i would be eternally gratefull. i could allways change the resistor and POT values to make the mA's match what i need exactly. I have been looking for somebody to help me out with this and i can find absolutely nobody who knows how to do this. thanks for the time. -Jakob

Asked by pianoman2011 9 years ago


no images? is it just me?

I don't know if this is just me, but I have a lot of problems viewing instructables on my computer in Firefox 3. I don't remember when this started because I use my boyfriends computer a lot, and his has no trouble with it. Thumbnails, images in the instructables themselves, and background images don't show up. Some of the text of the site is white and i can't see it without the background images, unless I select it. (also there is no problem in IE) I have tried deleting the browser cache and I've looked through FAQs but haven't found anything which works.

Posted by incessant_steph 9 years ago


How do watch glow backlights work???

I recently took apart a digital watch that had a green glow type of backlight. Looks like there was a backplate, behind the LCD screen, with what seems two contacts on opposite ends. No matter how I hook up these contacts to a 1.5V battery, I can't get it to glow. Any ideas????

Posted by tinkernaut 9 years ago



Is there a cheap way to make my own vinyl records?

Is there a cheap way to make my own vinyl records? Like, not just copy records, make new ones from computer recordings?

Asked by Eric95 9 years ago


Knex gun arsenals! ****UPDATE****

I would like people to post pictures of your arsenals! This is mine.

Posted by Vynash 9 years ago


Xbox live ... halo 3 UzUmAkI ClaN

Hey well for all of you Halo 3 anboys(or girls...hehe) i am making an halo 3 xbox live clan names the UZUMAKI CLAN! We only have 3 people in it so far but with your guyses help that could SKYROCKET! So for any halo3/ naruto fans who wish to join add me in your freinds list ill tell you what to do from there... here is my gamertag : HeLl x FiRe 55 and here is my bungie .net profile... :http://www.bungie.net/Stats/Halo3/Default.aspx?player=hell+x+fire+55&sg=0 THX! P.S. here is the clan pic!

Posted by tobi-kun 9 years ago


whats a good way to get more power from a knex gun without adding just rubber bands? Answered

I would like to know if the are ways to make knex guns have more power without have loads of rubber bands

Asked by nutty guy 9 years ago


Should all crossbows have handles? Answered

Should all crossbows have handles? DJRADIO NO VOTING =)

Asked by Wafflicious 9 years ago



iv been trying to creat an igniter for my spud gun that's small and portible i didnt know if enybody could help.

My gun is 4 ft with a 1" barrel and a 3" tank for hair spray.....this is just for funn not to kill animals..etc all i need is a spark it dosent have to be big just a little strong.

Asked by benderc 9 years ago


my jg m16 a4 airsoft gun is double feeding whats causing it.? Answered

My jg m16 a4 airsoft gun is double feeding whats causing it.?help

Asked by coolpizzadude 9 years ago




how often do you feed a leopard gecko?

I want to buy a gecko but i don't know when to feed it.

Asked by Martin White 9 years ago



is it possible to charge my laptop with the power present in the carrier wave which i recieve.

Ie.by storring it in accumulator till enough power is obtained?

Asked by 9 years ago



how can I print text on a t shirt? Answered

I do not want to use the iron on t shirt transfer, I am looking for more like screen printing?

Asked by 9 years ago


How do you make a lamp from 4w lightbulbs? Answered

Need to know soon.

Asked by cd41 9 years ago


Low hot water pressure

I the past 4 months I have replaced the water heater, water softener, and the pressure tank. Everything was working fine until I developed a leak in a PVC elbow from the outside water supply As soon as that was replaced and I turned the wter supply back on my hot water pressure dropped to almost nothing in all of the faucets. I am thinking some scale got lodged in the outflow pipe from the water heater and I need to apply high pressure air from one of the faucets to force this out.

Asked by 9 years ago


How do I replace a broken LCD in my Kodak M753 Digital Camera?

While the camera is physically fine, the LCD of the Kodak M753 is showing black / white and is unusable. The glass isn't cracked, and still takes pics perfectly, too. Was quoted £100 UKP for the repair in a camera shop, but would rather fix it myself, as replacement LCD screens are readily (and cheaply) available - but I would like to know more before attacking the Kodak M753 with a screwdriver! Can someone please point me in the right direction? Thanks for reading!

Asked by Coz_UK 9 years ago



How to make an illuminated planter?

How can I duplicate the illuminated planter from Design Within Reach for less than their exorbitant $525? http://www.dwr.com/product/outdoor/planters/bordato-30.do?sortby=ourPickshttp://www.dwr.com/text/viewer.htm?id=15067#

Asked by misabella 9 years ago


Kiteman, I would never expect this from you!

I've seen DJ Radio, Keith Kid, and GorrilazMiko up to these shenanigans, but Kiteman?? Honestly, now.Thoughts, my fellow Iblians?

Posted by Labot2001 9 years ago


The It Is Cute Blog seeks Cute Things

Hello fellow makers! I created a blog devoted to cute things and their skilled makers. It is located at: http://itiscute.blogspot.com/ Perhaps you know an artist / maker whose work we should feature? Maybe your own? If so, please leave a comment on the blog with a link to the artist's site! Thanks!

Posted by floorwaxdesserttopping 9 years ago


Fantastic clock (and other items) made from recycled circuit boards **UPDATED with photos**

Flickr user debbyaremdesigns has been building clocks, decorative items, jewelry and functional objects using recycled circuit boards and electronic parts. My favorite is here and shown below by popular demand (with other examples of her work):http://flickr.com/photos/debbyaremdesigns/2131590364/I love the marbleized effect on the CD -- how did she do it?Where can one get recycled circuit boards?

Posted by tinkernaut 9 years ago



Has Trauts left?

I haven't seen Trauts around in a while, has anyone heard from him? I know he took a lot of flaming from people who find basic physics to be too complicated; did he leave because of that?

Posted by knexguy 9 years ago


Didn't there used to be a i'ble for a hacked printer that prints directly on to circuit boards?

I searched and couldn't find it.? I did find a thread on cnczone.com about it, but i thought there was one here.

Asked by Scurge 9 years ago


Help for Android

Google has an operating system called Android. Click here to check it out. Anyways, I downloaded the desktop emulator and cannot get it to run!! I just get a mobile phone shaped window that says Android right in the middle of it. Can anyone give me any advice?

Posted by dla888 9 years ago



Inkjet printer question

I need help, making an ink jet printer think that there is paper in the loader when there is not, there is a small switch with a leaver which tells the printer that paper is going through the roller but if it is taped down then the rollers go for a while and then the printer realities that there is no paper, is there an easy way to fix this? Also on my ink cartridges there are 7 pins, does any one know what these do? I'm trying to build a laser cutter out of this printer where the laser is controlled by when the black ink would be spraying. Thanks in advance.

Posted by kcedgerton 9 years ago




Question on wind turbine design

Are the poles on the top face of your magnets or at the ends? The former arrangement exists in circular disc magnets and the small bar mags used in brushless motors. You may find that you can get more coils in your motor by winding multiple winds around a piece of stiff plastic. Similarly with disc magnets, alternating N/S with a smaller gap between them you may have more magnets and more coils. Also in many hobby brushless motors, the gap between mags and coils is small, 1-2mm. Do you have the mag coil arrangement on both the top and bottom? I am assuming that you have centering bearings top and bottom, but do you have thrust bearings? These are cheap and are simply balls in a nylon ring at the cheapest end of the market. You would have to sandwich these between big washers or metal plate. I think if all of this was done, the efficiency and output would increase. Dave

Asked by 9 years ago


My halo map (MODDED)

This is my halo map *Pistol: shoots sniper rounds zooms as much as sniper (infin ammo) *Shotgun: shoots more pellets and zooms in as much as sniper (infin ammo) *Rocket launcher: zooms as much as sniper (infin ammo) *Frag 'nade: is basicly a rocket round flies straight (TO USE THIS FILE YOU MUST FIRST BACK UP YOUR ORIGINAL BLOOD GULCH MAP) -THIS IS MY WEPON MOD DONT STEAL IT!!!-

Posted by goeon 9 years ago



how do I make super big sparks? Answered

I want to make super giant sparks to imppressive my friends because they don't think I'm really advacned And i am But I don't have time to think Of how to make somthing to impresvive them. I don't want any critism I just want answers.Sorry if I sound a little rude. Really sorry If i sound rude. I would like it to be like 1-2' long. Thanxs a ton

Asked by miiwii3 9 years ago


how do I make super huge sparks? Answered

I want to make sparks that can go up to 1-2' long to impressive my friend. My friends don't think I am good with electricity and I would like to Reall impressive them

Asked by miiwii3 9 years ago