Welcome to Instructables

On this page you can find links to some of our most frequently asked questions. What is this site? Instructables is a place that lets you explore, document, and share your creations. How do I post an Instructable? We offer a free and easy online class to coach you through posting your first Instructable or you can just wing it and start a new one today. How do I get help improving my Instructable?Ask the community for help in The Clinic. How does my Instructable get featured? The best way to get your projects featured is by following the Featuring Guidelines. Where can I learn more about contests? Our Contest FAQ has all of the information that you need to know about contests. What contests are launching soon? Check out our list of upcoming contests. Are you on social media? Yes! Follow us on Pinterest, Instagram and Twitter. How do I contact Instructables directly? The best way to contact us is through our Contact Page.

Topic by randofo   |  last reply

Are you going to ISTE?

Anyone going to ISTE this year in Philadelphia? Is there anything you are excited to see or do there?Instructables will be at the Autodesk booth along with our friends from the Tinkercad and Fusion 360 teams. Come find us and say hello, and learn about some of our new teacher-friendly features. You can also decorate a tote bag and grab some cool swag!

Topic by randofo   |  last reply

Welcome to the Instructables Teachers Hub!

Welcome to the new home for all things Teacher related on Instructables. We hope you'll explore the new features and come back often to find and share projects, inspiration, and classroom resources. As you explore the new Teachers Hub, you'll see it's easy to find projects by subject or grade level and sort them to find all the best and freshest projects.Be sure to spend some time in the new Teacher Forum. It's a great place to connect with fellow teachers and make new friends! You could start by introducing yourself here or finding a topic that interests you and join the conversation there. :)We'll be working to continuously update and support your needs in this new area of the Instructables community, so thank you in advance for your valued feedback and suggestions.

Topic by WeTeachThemSTEM   |  last reply

The Clinic // Get help with your Instructables!

Hello and welcome to the newest version of The Clinic! If you have an instructable that's not getting the attention you think it deserves, post it in the comments below for honest feedback and suggestions to improve it from fellow authors and Instructables staff. We want to help you create the best instructables you can! Curious about the basics of creating an instructable? Check out my FREE How to Write an Instructable Class! You can also read through our Featuring Checklist. Posting a great instructable has many benefits, including:More viewsMore comments and followersHaving your instructable Featured on the site Having your instructable featured on our social media accounts (Facebook, Instagram, Twitter, Pinterest)Better chance to win contests Driving traffic to your websiteP.S. While I know the goal for any instructable is to get Featured, it's not the end goal here! We're sure to hand out features, but please keep in mind not every instructable is feature-worthy. Even the most popular authors have unfeatured instructables! Don't let it get you down - you're still amazing! :D

Topic by jessyratfink   |  last reply

Be aware of the new LED light-door knocking scam!

It might just be a local thing for now here in AU but history shows a good scam often is picked up globally...The topic of the scam is a FREE upgrade of your old incandescent lights to modern and cost efficient LED lights.Down here we have these government sponsored and energy related initiatives for home owners and landlords on a more or less regular base.Sometimes it is solar cells, then solar hot water systems or better insulation, now we again have LED lights as last time not everyone took the offer.The offical way to benefit is to apply for it, usually a quick online process.After that a certified guy or girl makes an appointment and replaces the number of lights you specified.But to address more people and get around landlords door knockers are also used.These offcial guys provide you with some flyers highlighting the program, details about the process and so on.And if you are interested sign you up on a list for your replacement.It means you don't sign anything, you just confirm your ID and end on a list.A a week or two later you see a bunch of students running with little ladders and boxes of lightbulbs knocking on doors.So far so good and sometimes you even get older people replacing the bulbs for free.You can quite easy identify the official guys down here as the display ID tags with picture and those tags not just look professional but also contain all vital info and signs that correspond to the official government initiative.The scammers jumping on the money train however show a slightly different approach.Usually students with good language and promotional skills come in a nice dress and knock on your door.They come with a more less well made copy of the government flyer, usually not in the right format and not on nice, glossy paper.They also usually only show you a badge after you ask then to but won't follow the official code and have it displayed on the dress.Said badge, in my case, was of bad quality and was just an ink jet print laminated in bulk and cut straight, not even with the standard rounded edges...I played along anyway and showed interest, so I was asked if it is ok to have a quick look to check how many lights are required.Keep in mind here that the official guys won't need that info - they take this info by the actual amount of lights the students replace later on!I told the guy I only need 6 lights as the rest was already replaced by myself.Needless to say he insisted stating that he needs to confrim the amount as a requirement for the free replacment because the installer needs to know how many light are required...You would expect now to see someone walking through your house with the head tilted to the ceiling....2 minutes, maybe three...It took almost 10 minutes, for each light he filled a bit out on his form.Like lvining room, 3 lights, ladder required, toilet, one light, cover needs to be removed.....This time was used to get an impression of what is visibly available in the rooms...Once done the nice guy wanted me to sign his now filled out form and asked for my name so he can put it in the form.Don't know why I felt this urgent need but I asked nicely if I could actually have a quick read of the form before I sign.Reluctantly he agreed and handed my the form.What I spotted right away was that it was two pages that were not connected in any way, like with a stapler, not numbered either.The first page had all the details of my lights and requirements plus some not really clear looking government inignias.Like what you would end up with if you embed in a word document from a web page.Low quality instead of coming from a proper and official print shop.Page two then only needed my name, address and signature under the long list of fineprints.I did not even have to read it all to know it indeed is a bdly made scam.The FREE LED lights are still free, but each one comes with an installation fee of $35.This fee covers checking the fittings and light switches and if required their replacement at the costs of the occupant plus of course the disposal of the old lights.The offcial cooling off period for this type of contract is honored though.Well, that is until you read it all and double check the first page.14 days are granted for this officially and in the contract I was supposed to sign.With the exception that I automatically agree to have the replacement done at the convinience of the installer.Also added was a clause that states the contract is binding and the payment is required within 7 days once the lights are replaced.Page 1 though already had next Friday listed for the replacements of my lights....Means my cooling off period is reduced to 7 days....To cancel the contract I would have to send it in writing and with confirmation.And the arrival needs to be confirmed at least 48 hours prior to the installation date so the installer can shedule accordingly.Basically means I have to send this cancellation letter the same day I sign the contract to have any chance at all to avoid paying at least $35 per LED light.Needless to say I refused to provide my name and did not sign despite all well meant attempts to convince me otherwise.And although I can neither deny nor confirm to have made a specific phone call, some cop car picked the guy up shortly after when he was knocking on another door further down the street...Be aware if some really nice guy or girl offers you a FREE service after you opened your door!Be suspicious if they "require" entry to confirm or check certain things!It is quite possible this requirement is only to check for valuables!Do the smart thing and take what they offer in paperwork and ask them to come back a few days later so you can have a good read.Don't let them pressure you in any way!!!If it is a free service then you don't need to rush things and any official door knocker will be happy to give you the parperwork and tell you if you want to have it done you can simple use the details on the info material and register yourself online.And if you go that route you will see an official government portal for it.Even if a scammer goes as far as creating a website for the scam it won't provide you any of the standards you expect from your government.If you really decide to sign something on the spot or to provide personal details then at least read all the fineprints and everything else on all the documents!That means unless you know legal talk that you should have someone check it for you!

Topic by Downunder35m 

chainmaile aspect ratio

First of all , I welcome all . I fell in love with chainmail . I love its simple complexity , its beauty . I respect the time it takes to create a piece of jewelry . I made a couple of bracelets and necklaces for my kids and for my wife. I had no idea about the aspect ratio , or how a pattern should be loose or tight. Once the AR is firmly determined and once in range . I'm having fun , but I would like to know what your AR experience with certain patterns. Anybody willing to share some wisdom? DP ( Croatia )

Topic by Damir Podvinski   |  last reply

What kind of repetitive elements can you use on a surface with a gluing material inbetween to decorate it and look luxurious?

What kind of materials/repetitive elements/items can you use on a surface with a gluing material inbetween to decorate it and look luxurious?Check my pinterest folder, I want to make a parametric/curved wall ( https://i.pinimg.com/564x/34/e4/04/34e4045e39debc... ) and put plaster on it and some bounding agent to attach the repetitive elements https://i.pinimg.com/564x/34/e4/04/34e4045e39debc... what can I use?

Topic by DIAGONALLIS   |  last reply

Axial Flux Wind Turbine

24 pole, 3 phase alternator. 18 coils of #20 wire 80 turns each, 6 coils in each phase connected in series, then wired 3 phases in star config. Put out lethal voltages at a very low rpm. Using N45 2" x 1" x 1/2" Neo Mags, two discs of 24 each attracting each other through coils. I need to know what the number of turns would be for #13 wire, same configuration for charging batteries.

Topic by dna11207   |  last reply

I'm about ready to give up

For many years I have been a great follower of Instructables, and have contributed something like 70 instructables of my own. Prior to the recent site "upgrade," I would normally visit the site 3-4 times each day to see new submissions. Since the "upgrade," however, it has become so unstable that lately I only try to get to the "recent" items about once/day, and on most days that results in an error. In fact, over the past 7 days I've tried several times to submit this to the forum, but that would error out also. I'm now down to trying to launch Instructables about once/week, and that turns out to be a very iffy proposition. This was once a great site. It's sad that it has become so unstable.Note: Since there was not an appropriate category listed, I just selected "workshop."

Topic by knife141   |  last reply

what to do with a 50,000 volt Tesla coil?!

I just got a 50,000 volt Tesla coil (Oudin coil) for Christmas. I dont have a clue what i could use it for, i need inspiration. My uncle likes to surprise me with semi random things so other than shocking metal tables i just dont know what to do with it. ---from teachersource.com (where he ordered it)While more accurately called an Oudin Coil, these are commonly referred to as a hand-held "Tesla Coil." This coil is self-contained in a heavy duty Bakelite case which forms a convenient handle. The spark is adjustable from 10,000 to 50,000 volts at frequencies of approximately 1/2 megahertz. The high frequency spark produced is about 1" long and can be used for a wide array of applications. An instrument like this is intended for intermittent use only and must be turned off after 10 minutes of use. The electrode furnished is approximately 2" long and the instrument is furnished with an intensity adjusting knob. For 115v, 50/60 Hz. An improved SAFETY FEATURE is the ON/OFF momentary switch which is in the handle. This makes our Oudin Coil extra safe for classroom use. (Runs on standard North American line current, 110 volts 60 Hz)

Topic by i make shooting things   |  last reply

How To Unscrew Three-Pronged Screws Without a Three-Pronged Screwdriver?

I have a Gamecube controller I want to take apart, but it has triangle screws. They're like Phillips (four-pronged) but only have 3 prongs instead. I don't have a screwdriver for this, so I need a way to unscrew them.EXAMPLEUPDATE: Not trying to be impolite, but I am NOT looking for a place to buy this kind of screwdriver. I am looking for a way to unscrew them WITHOUT the specific screw driver.

Topic by Aeshir   |  last reply

what paintball gun do you have

What paintball gun do you have?

Topic by nerfer192   |  last reply

Methods for Powering 8 LEDs?

Hey Guys - My daughter has a small Little Tikes car which I'm adding 8 LEDs (3 per headlight & 1 per taillight) to. Each LED is a 2v 20ma. I've already started, but hit a snag. For testing the LEDs, I used a 9v battery with a 330ohm resistor on positive. This lit individual LEDs as well as 3 LEDs in parallel. My plan was to wire them all in sequentially then figure out what was needed resistor wise when done - bad decision. I have almost everything installed except power and now stuck as to what do do. Having 8 LEDs which are 2V / 20ma, exceeds the voltage a 9V battery can produce. Afraid to try connecting the 8 directly to 9V as don't want to risk burning them out. Just wanted to post to see what my best option would be - especially one where I wouldn't have to rewire everything again in parallel if at all possible. Thanks!

Topic by bzowk   |  last reply

How to make a waterproof clock?

I really hope someone can help me. I really need a clock I can have outside. I teach classes outside and I need to know what time it is. Waterproof clock prices are exorbitant... I bet they're easy to make. Nothing comes up when I google waterproof clock works. I have this huge metal disk I found by the side of the road and it would be cool to make that into a gigantic outdoor clock. But how to make sure it's not destroyed the first time it rains...? Can anyone help? THANK YOU!

Topic by kwilt   |  last reply

Native iOS and Android App Retirement

Hello Community! In an ongoing effort to make sure that Instructables is able to focus its product development efforts where they count most for existing an new authors, we are officially retiring our native iOS and Android apps. Note that this does not affect mobile web. I expect continued investment in mobile technologies for years to come, but we will focus on the experience of people using Instructables through their mobile web browsers, rather than through downloaded apps. For those keeping score, this isn't exactly news. We have not released new versions of either app in over two years, and they have become steadily buggier and buggier during that time due primarily to changes in their respective environments. Android 2 and iOS 5 were current when we released them originally, and Android 7 and iOS 10 are very different beasts. Simply keeping up -- even without adding anything new or fixing any bugs -- requires a constant investment of development time from Instructables, and prevents that time from going to projects with greater impact. The original purposes for the apps were: 1) To lower the bar to Instructables authorship by providing direct access to upload photos taken on smart phones 2) To improve the browsing experience by making it faster Since they were released, mobile technologies have progressed to the point that #1 is no longer a concern. Our mobile web editor already has full support for uploading images directly from your phone. #2 is also coming into striking distance soon, as browser manufacturers begin to standardize their implementation of offline content for mobile web sites, sometimes referred to collectively as "progressive web apps". We'll be watching these technologies closely, and we'll be among the first to speed up your browsing experience with offline components when cross-browser solutions become available. We have already developed (and will continue to expand on) Accelerated Mobile Pages, which mean we display nearly instantaneously when you tap an AMP result on mobile from Google. You can identify these pages via a lightning bolt in mobile search results: In short, the reasons that we developed the native apps no longer apply, and we're dropping support for them in favor of putting those energies where they are able to have greater impact for the community: Mobile Web. The apps will soon be removed from sale from their respective download stores. For existing users who have downloaded these apps and are using them currently: feel free to continue doing so, though we would urge you to upload your Instructable Drafts to the website as soon as possible. While we don't expect the editing process to break, no support is available should you experience issues in the future. You can also use the apps to browse Instructables, though I believe there are already some issues that have started adding friction to this experience. Thanks, all, for your continued support of our vibrant community! ~Devs

Topic by pseaton   |  last reply

Middle School Teachers

Are you a Middle School teacher? If so, say hello and connect with other 6th-8th grade educators. Feel free to share where you are from, what grade level(s) and subjects you teach, and anything exciting you did with your students this year or plans you have for next year. :)

Topic by WeTeachThemSTEM   |  last reply

High School Teachers

Do you teach 9th-12th grade? If so, say hello and connect with other High School educators. Feel free to share where you are from, what grade level(s) and subjects you teach, and any exciting projects you did with your students this year or fun plans you have for your classes next year. :)

Topic by WeTeachThemSTEM   |  last reply

Site update?

What happened to the instructables site? I can't find anything, no "recent" "featured" "topics" or "question" good luck finding this post. Is it an update or does my computer just hate me?

Topic by liquidhandwash   |  last reply

10 Best Electronics Suppliers

First off, I would like to give notice to Electronics Projects for Dummies for most of this info.I wanted to make a site with many of the best sites to buy Electrical Parts, because it can sometimes be a strenuous activity. I have 10 here, because if you can't find something on one online store, you might be able to find it on the next.Reynolds ElectronicsReynolds Electronics is a good supplier of remote control components, micro controllers, and robot kits and parts. One feature that stands out on Reynolds Web site is the clear and helpful project/circuit tutorials. You can also find links for educational books on topics such as robotics and microcontrollers.Hobby EngineeringHobby Engineering is a sit slanted towards the hobbyist. This site carries some useful items that can be harder to find from other providers who are catered towards the corporate customer. it also has a good supply of micro-controllers, robot kits, parts, ad miscellaneous components and tools.All ElectronicsAll Electronics has an incredible selection of many of the useful items you would use to build your project. They are very inexpensive and it is easy to find your way around the site. This site also has a "consumer comments" section where the consumers get to talk about the quality of the product and more. (Thank you westfw)BG MicroBG Micro is a cool site for rare and pretty neat gadgets as well as a nice selection of alot of the items one will need for a weekend project. There is also a very nice search engine at the top which lets you search for an item you can't find on the left. (Thank you Las Vegas)Jameco ElectronicsJameco has a very nice site catalog. It's not very big that you sspect a forest was sacrificed in its making. I has great color photos with relatively easy to find components. This is one supplier wih a low price fuarantee which means that if you can show a part offered for less, the lesser price is honored. jameco also provides lower priced generic products as well as name brands.DigiKeyDigi-Key is a large distrbutor of components from various manufacturers, offering a very large catalog with lots and lots of choices. However, the site uses small print that might be hard to ead. The catalog includes line drawings but o part photos, but it does do an excellant job of labeling the parts. Overall, Digi-Key has a huge selection of products, but they might need a little looking to find them.loading...Mouser ElectronicsMouser ElectronicsAnother large distributor of components from various manufacturers is Mouser. I like how Mouser's site allows you to compile separate orders for different projects. You can come backa s many times as you like to complete your order and make your purchase. We also like how Mouser label parts because the labels are easy to read and provide alot of information about the specific part.Like Digi-Key, Mouser provides a very large catalog.RadioshackRadioshackEveryone knows Radioshack!. This electronics convenience store is pretty much like any food convenience store: CONVENIENT BUT EXPENSIVE. If you are stuck at 4:30 on a Sunday afteroon needing a small part to keep working on your project, this store is right for you. Be aware that not all radioshack are equal.Fry's ElectronicsFry's ElectronicsFry's has stores in nine states, and if you are lucky enough to live near one you can browse the isles in person. Fry's stocks all kinds of electronics and parts including an EXCELLANT selection of IC chips.Goldmine ElectronicsGoldmine ElectronicsIf you are in the market for bargains, try Electronic Goldmine.. This online store often offers sepcials that can save you money. Based in Scottsdale, Arizona, Electronics Goldmine offers great help with international orders and also offers wholesale items on auction on eBay.Quick Tip: Try clicking Electronic Goldmine Treasure Ball for the best deals!FuturlecFuturelec offers a very nicely done site with color photos of the parts that makes for easy browsin. Futurelec also offers semicnductor news links and also links to recently added parts to help you keep on the top of the latest and greatest as well as PCB design and manufacturing services.[htpp://maplin.co.uk Maplin]MaplinThe British suppplier Maplin has stores scattered around the U.K. and also offers an online store.Unlike electronic gadgets and appliances that operate on different voltages in European contries, electornic components are pretty standard. Although Maplin will ship overseas, you might want to check out U.S. Suppliers first.SparkfunSparkfun was originally a PCB Manufacturer, and turned in to a company well beyond their expectations! They have a large variety of PCBs, LEDs, and MANY more everyday electronics components. The site is well organized with so much to choose from!

Topic by Brennn10   |  last reply

Sand carving

I’m new here and just wanted to share what I do. I have been glass sandcarving for over 20 years and used to teach it.

Topic by 1Sandman   |  last reply

555 monostable timer

I've no idea what I'm talking about here but can only explain what im looking for which is help. I'm basically looking for a relay or multifunction relay not really sure but here's the plan. When my smart plug is turned on (at certain programmed times through the smart plug app) to provide power to a 12v 6amp pump (I have 240v ac to 12v DC transformer pluged into smart plug I'm in uk) I would like for this pump to turn itself back off after 10 or 15 seconds. I cannot for the life of me find an analogue or digital timer that can do seconds. The smart plug can work down to minutes and not seconds. So basically smart plug on = pump run for 15 seconds cuts itself off and then the smart plug turns off once the minute is up and when plug is on again at next programmed interval it does same thing. Any help would be great as I've no idea what I can buy or try to make thanks When trying to research I hear about 555 monostable circuit but I don't know how to wire something up or what to buy to make this work.

Topic by croyf85   |  last reply

Last update make this site pointless.

Tanks for making this site pointless by removing RECENT option.

Topic by gonzzo   |  last reply

Moon light timer

I would like to build a led light that switches on and off with the moon. On when the moon rises and off when the moon sets. Would also like no leds on at new moon and an additional led comes on until full moon is reached. The process then reverses an an led goes off until new moon with no leds on. I would also love the light output to be 4150k the colour of moon light and about 1 lumen at 1metre distance.

Topic by Ausie Steam   |  last reply

Rotary Tool neck thread size

I have several ideas for rotary tool accessories that would make my life easier, but they would have to be attached at the neck. So I need to cut out a hole, and tap it out to the right thread size. Anyone know what that is?

Topic by BoomGuy   |  last reply

Feeding baby praying mantis (newly hatched)

FYI to anyone who has or wants to know what you can feed praying mantis babies right after they hatch. The egg sack i have been "protecting" (i thought) til spring has just hatched a day ago and its only december, my plan was to let them go after they hatched in the spring, but since i didnt keep the sack cold, it hatched now. After i freaked out for abit seeing i have about 50 or more TINY mantis all over the container i put the sack in, i called and called ALL over but no one would take them, and i cant let them just die. Everything i read about them says they only eat LIVE bugs..and they have to be small...really really small..like pinhead crickets or fruit flies...well...YUCK..i dont want that in the house...but if thats what they need then so be it..UNTIL...i called a bait store and the guy (i wanted to KISS him for this info) told me to put RAW MEAT on a string so it sticks in small peices and hang it in the container..IT WORKS!! they went right for it!! SOOOO.........if you dont want or cant get tiny live food for them...FEED THEM RAW HAMBURER MEAT on a string!! this picture is the mom, isnt she beautiful! haha..i mean it!

Topic by Chiana   |  last reply

Laser Cutting in the Classroom

After creating a makerspace at my elementary school, I was always on the lookout for fresh projects and new tools and a laser cutter was that one big item at the top of my wishlist that I just never got... but, I know some teachers and librarians who are brand new to the world of laser cutting and would love pointers from other teachers who have already worked through some of the challenges of starting something new. :) So, if you have a laser cutter in your classroom or school makerspace, please share any tips or suggestions you might have for any teachers who are just starting out with one at their school. Also, feel free to share any cool projects you and your students have done or programs you use.

Topic by WeTeachThemSTEM   |  last reply

Q: Others having difficulties about reading private messages in istructables profile page?

HiI just wonder, is it just me.. Or is there some known, wider issues on istructables page, that prevents reading private messages?I have tried couple days to read my messages, but when i click "Inbox", i end to the front page of the instructables, instead to my mail. :( ThanksTuomas

Topic by The other Finnish guy   |  last reply

Water-damaged PCB repair

So water leaked in to the General Electronic Module (GEM) on my pickup and now it's acting all funny. A/C runs when the ignition is off, randomly switching to 4L, airbag light chattering on and off, etc. I want to try and repair it. My intuition is that it just acts up when there's stray conductivity between traces/elements, so if I give it a good clean and keep it dry it should work like new.However, I noticed upon pulling it apart that there's some corrosion taking place. Can anyone suggest a good way to repair these traces/SMD resistors? I have a soldering iron but heavily oxidized things don't take solder well in my experience. Or should I just put some lacquer on it and not worry about it?Thanks!

Topic by RelaxedSoup   |  last reply

What is going on? I want to see ALL the instructables, not a "homepage"

What is going on? I want to see ALL the instructables, not a "homepage". Stop messing with what works.

Topic by carlos66ba   |  last reply

TV antennas and what is possible indoors

Back in my young years a TV antenna was on the roof, quite big and only required to get 3 or 4 channels at best.The basic design of these Yagi antennas has not really changed since then.Same for the antennas required to get UHF and VHF channels at the same time.They either comes as two seperate antennas with a mixer or as a UHF antenna with some added loops for UHF.To talk some basics:For UHF you can get away with quite small dimensions for your antenna bits.After all a quarter wavelengths here is only around 15cm long.With VHF though we get already 30 to 40cm here depending on the channels.So called bradband antennas claim to be able to get a wide range of frequencies.That however is only true for their dedicated frequency band.If you take a normal whip style antenna then this becomes obvious - just compare the lenghts required and you realise "going the middle way" will mean neither UHF nor VHF would get any usable reception.For a long time now there is the option of so called "fractal antennas" to get better TV reception....Fractal antenna? What the heck is that?The theories behind them are about as old as fractal antenna designs that were not even considered to be fractals.Let me explain with the example of a standard FM radio antenna.For them we use frequencies from about 88 to 108MHz.And of course, for our cars they are always on the roof or mounted somewhere around the wheel arches.Some cars however does not seem to have any antenna depsite having a working radio.In this special case rest ensured they do have one, usually behind the plastic bumper bar ;)I like to go off road every now and then and lost count how many times I had to replace my antenna after getting to close to some bushes and trees.As a solution I used some thin wire to create a L-style anteanna on the inside of my windscreen.And funny enough it picks up more stations than a "proper" antenna outside.Really old design and if you think about it then an antenna with a kink that looks like L is ""self similar" - the definition of a fractal ;)More complex shapes like the Sierpinski models do exactly the same just in one more dimension.Cell phones use them as well as you WiFi router that has no external antenna anymore.Their designs and looks are so different that it is next to impossible to list the currently used shapes here.What it comes down to, when you just take a very basic flat or wire shape is that the straight single segment of the active antenna is split into one or many shorter segments that change the angle.They all have similar relations to the wavelenght still.Means really long segments might be half of a wavelength while the shortest bits are just 1/64 of a wavelength.Think of it (far too simple of course) like amny matched antennas combined into a single one.With that often comes a destinct radiation pattern, usually with a quite narrow beam angle that provides a quite high gain.Are fractal antennas any better than for example a proper Yagi antenna?You can ask 100 people and you get 100 different opinions for this one.This is mostly due to some simple facts like:Not caring about actual comparisons.Not being accurate enough when building the fractal antenna.Using just very basic equippment to compare results.For example when you have a 30 year old and quite small TV antenna on your roof and struggle with digital TV reception than you might want to just replace it all.In some case even the old rabbit ears on your TV set will work better.But take modern Yagi antenna with 12 or more segments and even station that are 100 miles away have a good chance.Comes down to possible gain, frequency match and of course how well the antenna is aimed at the transmitter.Then why is it that some fractal antennas still seem to perform so much better?The big antenna scam....If you paid attention during the intial DVB-T rollout in your country then noticed two things.a) You were told you need a TV or set top box capable of receiving DVB-T signals.b) You need a suitable antenna.Well, A is obvious but for B a lot of people got scammed badly.You see, in almost all cases the frequencies allocated for TV signal did not change at all.And an antenna really does not care if the incoming signal is analog or digital - it only cares about the frequency.But more and more local stations often meant that the trnsmit power is limited.After all it makes no sense to have a 500kW transmitter if the area to cover is only about 20 square km big.So people were told they need new antennas once the noticed digital TV is more like playing Tetris, blocks everywhere....You analog TV had no problem with a slightly weak signal, you did not really notice it unless the weather was really bad as well.All the benefits of digital TV however only work with a proper signal strength.If your areas still has both analog and digital TV channels then have a look on how your local transmitter provides the signals ;)Part of the big scam was hiding a very simple fact:All analog TV is transmitted in a horizontal orientation while almost all digital TV is transmitted in a VERTICAL orientation.Ok, we already gain and ignored it but why would the orientation be important?Your radio antenna is vertical because the FM signal is transmitted the same way - the "waves" if you like go up and down like a sine wave.You still get reception if you turn the antenna 90° to make it a horizontal one but you will realise that weak station are no longer available.The same happened with digital TV.And if there is only digital TV left in your area then simple turning your antenna 90 on the mast to have the single elements vertical instead of horizontal gives you top reception again ;)If you struggle to get all station then just try it out before buying a new antenna ;)Modern fractal TV antennas come paper thin and often with rediculous claims in terms of gain and range.On Fleabuy you can even find models claiming to get stations from over 2000 miles away LOLSome even come with the fake claim of being omnidirectional, meaning it does not matter where you place them or how you orient them.A fractal antenna can't change basic phsyics though...High gain mean highly directional or at least with a very flat radiation pattern instead of being more like a sphere.A high bandwidth means you compromise on the gain and/or the phsical dimensions.For example a thin whip antenna is quite limited in the optimum bandwidth while a piece of tubing provides amuch higher bandwidth but at the expense of gain (and some other problems).A fractal antenna can compromise between the two worlds much better than anything straight.And you would even need to make the traces on the plastic extremely wide because you can simply add different lengths for different frequencies.Means a wideband fractal antenna for FM, VHF and UHF basically is three different antennas combined into a single one.It also means that there is usually always more than just one single element of the antenna that is receiving a signal.If you experimented with WiFi antennas for your router or modem than you certainly found the famous Pringles can antenna - highly directional and with an insane amount of gain.Works exactly like a simple directional microphone.And you could, at least in theory do the same with a TV antenna - if there wouldn't be the problem of the wavelenght.A pringles can works for WiFi because the wavelenght only requires an antenna of about 3cm in lenght.You might not want a row of steel drums with a diameter of around 80cm on your roof just to watch the news though...Ok, if I need a new antenna anyway then should I get a fractal antenna or not?I try to make it simple:Roof option not possible or too costly AND your transmitter is not too far away then try one of the cheap paper thin antennas you find online.If you already have an antenna on the roof that is suitable for the frequencies you need then check it to know if it is still any good.With age and weather comes corrosion and some antennas are connected badly in this regard.Sometimes you are lucky and all it takes is to cut off a few cm of cable to get back to clean copper and to give the terminals on the antenna a good fine sanding or a wire brush treatment.In other cases you might find an amplifier under the roof that has faulty power supply ;)And well, certain animals love to chew through your cable...If all is goo from antenna to TV then as said try to flip the antenna 90° to get it vertical.No, I did not mean to point it up to the sky..... ;)I mean rotate it around the x-axis if X is pointing in the direction of the transmitter...

Topic by Downunder35m 

Where is the induction kettle or hot water system?

No modern kitchen these days is complete without at least a single induction cooktop.Convient to even place on the table to keep things warm but also nice to have 4 or 6 "hotplates" to cook on that are actually not getting hot at all.When it comes to efficiency induction cooking tops all others as no heat is wasted.Which brings me to the point...A single cooktop goes now often for well under 50 bucks.Although the base might end up slightly higher than a normal kettle I fail to see why we don't have induction kettles in our kitchen.Why wait 12 minutes to have the thing boil if you can do it cheaper and faster?Way more convinient too as there is no pesky contacts and heating elements anymore, no failure due to leaks either...But what really got me wondering is the hot water systems or heating options like prefered in Europe.Here you have a central "boiler" so to say and water circulates through valves into finned radiators, usually located under windows.We have oil filled radiators of this kind as free standing units that are now being phased out because they waste too much energy with their heating elements.Same story for just hot water :(On demand systems are getting more popular now outside Europe but still the common solution is to have a few hundret liters of water in a tank that is kept hot no matter how much of it we use.Be is gas or electric both types have their drawbacks and to get ahead of the corrosion that always kills them we now opt for expensive stainless steel tanks...Using induction it would be very easy to have a fully sealed tank and to actually only heat what needs to be heated without wasting too much energy.The "heating" element could be just a steel plate inside the tank with no connections to the outside.The gap between wall and element doubles to make the water circulate.And changing from a fixed timer to a temperatur control system to turn the induction element on and off is not hard either.Do you have an induction based hot water system, heater or maybe kettle already?Would love to see it...

Topic by Downunder35m 

Elementary School (K-5) Teachers

Do you teach at the elementary level? If so, this is the place for you to introduce yourself and connect with other K-5 educators. Where are you from and what grade level(s) do you teach? Say hi and share something exciting you did with your students this year or project ideas you have for next year. :)

Topic by WeTeachThemSTEM 

List of Upcoming Contests (updated 6/4/19)

Hello everyone! Below is a partial list of the 2019 contest calendar. Keep in mind that this list is subject to change and contests will continue to be added throughout the year. The contests below are already in planning, and I've left off ones that we're still trying to decide on. The months indicate when the contests will be launching. All contests will launch near the beginning of each month. Keep in mind that the list below is not set in stone. All contests and dates are subject to change!JulyPlanter Challenge Design and create a planter or potPaint Challenge Painting tutorials, tips and tricks, using paint to refresh old itemsBBQ Challenge Share your best grilling recipes ands favorite sidesSew Tough Challenge Sewing projects, but extra rugged and practicalGame ContestOpen to all games and gaming inspired projects: cosplay, props, tabletop games, arcade machines, controller mods, etc.DIY Summer Camp ContestPitch a tent, learn archery, build a boat, get campyStone, Concrete & Cement ContestGet stuck between a rock and a hard place and make cool stuffAugustFlying ChallengeIf your project flies, we want to see itSpicy ChallengeFeeling hot, hot, hot... when it comes to these recipesClassroom Organization ChallengeShow us your favorite solutions to tame the craft and work supply madnessMake it Move ContestAny project that moves is eligibleMetal ContestUse metal in your project - head banging optionalIndoor Lighting ContestWe love lampTeacher ContestTeach us your ways, oh educators!SeptemberMotor Vehicle ContestCars, trucks, vans, motorcycles... you get the ideaMaps ChallengeMake cartography great againKitchen Skills ChallengeShare your kitchen knowledgeCNC ContestBuild a project using a CNCMultidiscipline ContestOpen to projects that combine two or more disciplines, like woodworking AND sewingSkateboarding ContestBuild a board, share tricks, wax every ledgeHalloween ContestCostumes, props, decorations, food and moreOctoberAfter School ChallengeAfter school projects and activities Book Character Costume ChallengeLet your imagination run wild and bring your favorite book characters to lifeCandy ChallengeSugar and spice and everything niceArt Skills ChallengeDrawing, painting, sculpting, animation and moreMade with Math ContestCombine math with makingRobots ContestMake yourself a robotic friendNovemberMeal Prep ChallengeGet a gold star in being an adult and teach us how to meal prepFashion ContestIt's called fashion sweetie, look it upInvention ContestSolve everyday problems by creating something newAssistive Tech ContestUse technology to make life easierHome Decor ContestRefresh and restyle the DIY wayReuse ContestWork with what you've got instead of buying newDecemberPCB Badge ChallengeCreate custom PCB badges using EagleCrazy 4 Coding ChallengeShare fun coding projectsCookies ChallengeC is for cookie, and cookie is for meFiber Arts ChallengeThe challenge for all textile arts: weaving, crochet, embroidery, sewing, etc.Instrument ContestMake some noiseMad Science Fair ContestOpen to all science fair projects and experimentsShelving ContestGet creative with shelvingMake it Glow ContestAdd LEDs to all the things! *All contests and dates are subject to change. Please leave suggestions for prizes here. You can also leave suggestions about contests here. Have a contest question? Check the Contest FAQ!

Topic by randofo   |  last reply

How Instructables Hooked Me Up

Has posting a project on Instructables and being a member of our community helped you nail an interview / get your dream job / propose to your partner /  get an A on a school project / muster up the courage to ask someone out?? We want to hear your stories! Please share them below

Topic by kazmataz   |  last reply

Website-BUG: Login-Cookie-Handling over multiple PCs with feed

I had this problem in the past sporadically but never saw a pattern till recently:I come to instructables.com, i am already logged in and click on "feed" at the top.After a while an error pops up telling me a Rerouting-error happened. (Umleitungsfehler in German).I noticed, this always happens after the following action-pattern:- I visit instructables.com and log in on computer A and i DONT log out there but only close the browse.- I visit instructables.com on computer B. I am seemingly already signed in from the last visit here on Computer B at instructables.com. - If i now click feed (On Computer B), the error happens.- If i logout and log back in on Computer B, the error is gone on this computer B, even over Firefox-restartsAs far as i undestand, as soon as i log in on computer A, a new login-cookie is created on Computer A and the cookie on Computer B will no longer be valid next time.Now, if i come to instructables with computer B, the cookie somehow still is interpreted valid and logs me in (I appear to be logged in with my avatar visible at the top right). However, if i want to go to my feed, it seems Instructables checks again the cookie and figures out that i have a no longer valid login-cookie on this Computer B due to my login on Computer A and refuses to redirect me to my feed. This gets sorted with Re-Log on Computer B, creating a NEW login-cookie on Computer B and all is well again on Computer B. Now i can play the same game on Computer A with re-log. :)I hope, this error-report helps you guys in pinpointing and fixing an issue with a Login-bug as it seemsAnd Why to hell do i have to define in which channel this belongs and you dont have a channel "website of Instructables"?!? I hope this is not lost in "Circuits" - "Software" which was the closest i could find to a website-problem... Geez...

Topic by Orngrimm   |  last reply

Recent Feed Page

We have heard your feedback loud and clear, and we will be bringing back an easy way to see all recently published instructables. This requires some dev time because we changed things under the hood and need to do a little work to re-create this page. We hope to have it back shortly.We appreciate your patience as we continue refining the site after this release.Update:The recent feed has been released and can be found at this link:https://www.instructables.com/feed/recent/You can also find a link to it on your feed page.

Topic by randofo   |  last reply

Change yarn colors ?

How do I change yarn colors in crochet With pictures?

Topic by Godloveus1962   |  last reply

Heavy duty UHF CB radio antennas and why cheap can be much better....

If you not a fan of normal road cars then you might get some 4WD and go off road every now and then.There are even those doing trips to remote locations that take a few weeks.An essential piece of equippment these days is a UHF radio.In a convoy you might get away with a handheld one if the cars are not too far apart and the terrain suitable.Most peole however opt for a permanent installation in the dash or roof console.After that decision comes the hardest and often costly part: What antenna to use....If you trust certain online reviews and manufacturer claims then one thing becomes quickly obvious.If you need a sturdy and powerful antenna then you have to pay top dollar.Some come with heavy spring bases claiming to protect the heavy fibreglass rod if you hit a bush or trees branch.There is always a compromise between weight and stability.And trust me, on the right corrugations you prefer not to look at your antenna....So how are these expensive antennas made?As I don't have any own pictures and don't want to steal them from the net: Please search for the terms used if you don't know them already.To answer this let me go to the other types of antennas you can get for your UHF radio.There is the famous rubber ducky - a stubby antenna best suited for short range on difficult terrian.Then we have the fibreglass whip antennas that have more or less coils integrated or even consist of one single coil with different spacings in sections.Good for normal road use, not so much off road as they won't tolerate too much vibration, they often snap off the base screw.Most people now just ignore the short whip antennas of 15 to 30cm length as they usually only come with a gain of around 4.5-6db.I will explain later why that might be a misconception.The last ones are those steel whips with one or two "loading" coils.These coils electrically shorten the antenna.They also provide a matching to the 50 Ohm required for most transmitters and antenna cables.Usually they are designed to be 5/8 Lambda antennas.A good antenna for just receiving, like when using a scanner is not critical in length.Transmitting however means you need a proper Standing Wave Reflection or SWR ratio.For this the antenna needs to be tuned.To be of any good use your antenna needs to match the transmitting frequency.This works best if the antenna length is at 1/2, 1/4 or 5/8 of the corresponging frequencies wavelength.Also called Lambda if you look for antennas.In the good old 27-MHz days we were used to quite long antennas in our backyard, for the car we then opted for 1/4 of this - usually around 2m in length.For UHF however 1/4 wavelength already means you are down to about 16cm...Going for 1/2 is a good thing here as it is still quite short at about 34cm.Real difference when it comes to these Lambda factors is the radion angle produced.You can imagine a 1/4 to look like a huge donut with no hole, about 25° for the radiation angle.At 1/2 this will be flattened out to around 20°.A 5/8 Lambda ntenna can get as low as 16°.Imagine it like a flashligh that has adjustable focus.The light source is of fixed output as your transmitter.The lens does the job of the antenna.If you make the beam more narrow then the light intensity of a certain areas at a certain distance will increase.Means for the radio you get a longer distance your signal can travel with enough energy.This however comes at a price!Imagine you are at the bottom of quite stepp mountain and your mate is up on the top about 2km above you.A high gain antenna with a narrow radion pattern might not even reach up there, while a short stubbie with just 3db still has a chance due to the more spherical radiation.Also explain why low gain and with that short antennas work best in hilly terrain...Back to the thick ones...As you can see you can basically hide any type of whip antenna into a fibreglass rod.But most of the are as said "ground independent", means unlike your normal whip they don't need the spring or foot to be of low resistance to your car's body.How does that work?Well, exactly like these ground independent whip antennas with a spring base or metal pole base work.You know the earliest antenna was a dipol - look it up on Wiki ;)For our CB radios that means you have a metal rod or spring that is about 1/4 or in some cases 1/4 of the wavelenght long.This is connected to the shielding of the coax cable and provides the required ground for the mounted antenna.The big difference is that only too often a dirt cheap dipol is hiding in your expensive fibreglass rod ;)The complete antenna might bring over 2kg on a scale, but the actual thing allowing you to receive and transmit is a few grams of coax cable...HOLD ON A MINUTE!! Some will say now...My whip is 70cm long and my expensive heavy duty one with 9db is 2m long - how does that work with your wavelength theory??Well, it is not my theory, just a fact ;)Imagine a 1/4 Lambda dipol, then it would be all up around 35cm long.And funny enough, that is about the length of a $180 heavy duty stubby if you just tak the rod itself.Go 1/2 of Lambda and you get an overall length of the dipol of around 65cm - add the metal rod making the crew that holds the fibreglass rod and you have the common 70-75cm heavy duty antenna...Anything above this length usually is either just a long rod with noting above the 75cm mark or simple has the 75cm long dipol made from the coax cable at the top with the antenna cable going down the otherwise empty rod.Ok, I got it, either 1/2 of the wavelength or 1/4, so about 35 or 16cm long.Ground independent we add either 1/4 for the spring base and rod or 1/2 for the longer ones.And how again does it work with the gain of an antenna?If you trust Wiki then it comes down to the radiation pattern.These heavy duty antennas usually come with around 6 or 9db, the short ones with 3-4.5db.These values might give you an indication about the theoretically possible distance you can transmit but nothing about the terrain it is suited for.Common rules of thumb created by those selling antennas and radios is that you a high gain antenna on flat terrain and a low gain antenna in a hilly area.Around 4.5-6db seems to be the golden ratio here as these anteannas are equally bad for both extremes in terms of terrain options.What you really would need to know is the actual radiation patterns in a three dimensional plane.A straight whip or dipol as a more or less donut shapead radiation pattern.However, location affects this!Mounted in the middle of the roof it is closest to perfect, while at the corner of your bumper bar you will distord the donut and also block parts out with the body of your car.This is why for this type of mounting elevated antennas are prefered.Makes no sense to have a 16cm long stubbie mounted so the top is still lower than your bonnet...Any antenna with a loading coil (or several) or top load will have a distinctively different pattern.We speak of so called "lobes".If you see it in 2D then for example a 1/2 lambda straight whip will look a bit like the infinity symbol.A 1/4 Lambda of the same style looks more like two ping pong bats joined without the handles.Those with loading coils or linear arrays made from coax cable however can produce multiple, prefered lobes.Usually they are in the 4-6db range and claim to be "universal" or as "allrounder".Here you get a quite narrow main lobe of 12-16° with one or more but much shorter lobes going upwards at about 10-30° depending on the configuration.At short range, like in hilly terrain both lobes overlap while you get a dead area at greater distances.You can sometimes notice that when you are on a low level talking to someone up high.There are cases when with a bit more difference in angle to each other (in terms of height and distance) the signal jumps up a few numbers.You just went from the dead zone into the lobe ;)With just a db value for the anteanna but no details about the actual design, heavy duty antennas can fool you badly.In mayn cases a 1/2 Lambda straight whip on the roof will outperform a costly, heavy duty antenna mounted to your bullbar.This is the reason why the expensive ones are the biggest cheat - they just elevate a quite small antenna above your roof line.And since it is heavy it needs a big spring and you hope it will not break if you hit something on a narrow track.All while the thin stainless stell whip with the cheap magnetic base just flexes under all obstacles with no damage at all.Plus, if you really get into the thick jungle you can just take the magnet off until you are through LOLWhy is a SWR and power meter still an important tool to invest into?Those remembering or still using 27-MHz radios only know too well why you need a proper SWR and power meter.With the lenght of the antenna at these low frequencies and affecting factors new the antenna proper tuning is a must.The bandwidth of the channels also means you have to tune the lowest and highest channel so the are basically even, anything else and the old guys would scream "UNACCEPTABLE!" ;)Especially it you want to get the last out of your system without going illegal.For some reason we accepted the claims that an SWR reading of around 1:2 is fine and acceptable.Most of the radios lower the power output to protect the transmitter if the SWR goes to far out.Allows for simple mass production of antennas with fixed cable lengths that are usually well overpriced.The most expensive bit is the cable itself here...I had no time to build an analog SWR and pwoer meter that works properly on 27 and 470MHz, so I ordered cheap SW30 from China.With that I first checked my little collection of antennas then those of some of my friends.This includes everything from short rubber duckies over loaded and straight whips to heavy duty models.One thing that was obvious right away: most are far away from an SWR readin anyone with a 27MHz groundplane antenna on a long mast would accept.And only one heavy duty antenna had a SWR readin of below 1:1.6 for channel 1 AND channel 40!That one was relatively cheap noname brand.With that sorted I decided to tune at least my steel whip antennas.To my utter disappointment they were all just a tiny bit too short - a thing that would have caused a proper 27MHz antenna manufacturer to to keep a large stockpile of his antennas...I had one though that was longer than needed.And before you ask: Yes, I tested them on both my elevated bullbar mount AND a direct mount on the roof rack.Did not change much for the bad ones so I ignored the mounting position for the tuning.I checked the power once for both channels on my prefered antenna and got 4.4W.Mind you that one has a SWR reading of 1:2.2 and will no longer be used as I can't be bothered to make it longer.For some reason I thought I check the SWR and power everytime I cut a bit off the antenna instead of just watching the SWR reading.At original length I had a SWR of 1:1.9 on ch40 and 1:1.75 on ch1 with 4.6W.I kept trimming down by about 2mm increments until I got an even readin of 1:1.07 on both channels.And with every trim the power went up a little bit.I have a friend that is or better, was just at the brink of being unable to reach from my driveway when he is parked in front of his house.A radio check after the tuning revealed that instead of coming with a lot of static noise and sometimes cut out I got a solid reading of 2 on his end with a much more acceptable level of noise.However, I still struggles as badly to hear him...Funny thing is that test was with just a plain and straight whip of 1/2 Lambda, in my case the tuning resulted in a length of 38cm from the base of antenna screw to the tip.My fancy 9db high gain antenna that is just over 70cm long did not even reach him while I could hear him slightly better than on my tuned one.Changing the mounting to the roof rack gave me a clear reception and a signal strength of 4 at my friends end with no noise.Elevation and nothing around the antenna does matter...After all this, would I still bother to buy a ready to go antenna for 470MHz?Only if I had to.Getting some RG58 cable or re-using it from on old antenna is cheap enough.A standard screw mount with a grub screw to hold a steel whip sets you back less than 10 bucks, from China even cheaper.And most will find a soldered on connector on the other end of an old antenna to be salvaged if required.If you don't have any sring steel wire of about 40cm length then think out of the box ;)The packing of pillows and such often come with a sring steel wire to make the plasitc floil keep its shape, some old suitaces have thicker wire doing the same.And if you ask nicely you might get a bristle or two for free from a street sweeping machine at your councils depot ;)After all we only need a maximum of 40cm to have enough left to trim and tune down.What is left to do?Of course some distance tests to check how well such a simple antenna really really works in comparison to commercial models.I only have one 9db antenna and will check it first to see if on flat terrain there is much difference in distance for transmitting.Unless this difference is well above one kilometer I will not bother with a high gain antenna like this anymore and instead opt for a longer mast and 1/2 Lambda.Another thing on the to do list to try a ground plane antenna with topload to squeeze the radion lobe down to under 15°.The resulting antenna would be quite short here and using an elevated mast is a must have to get over roof level with at leat a few wavelengths of distance to the roof.I guesstimate that an optimised antenna of this style should result in a distance increase of about 10-15km of flat terrain while being utterly useless in a hilly areas.Plus, such a design is not really suited for a vehicle going fast on a freeway, so it will go on my house instead.

Topic by Downunder35m 

Fun with firecrackers?

Does anyone know how to have a lot of fun with firecrackers, in a weird way kinda, other than putting them in bottles and throwing them?check out my youtube

Topic by halzep   |  last reply


How do you unfollow members? I accidently pushed someone's follow button and I don't want to follow them.

Topic by MissSongbird   |  last reply

(home made lightbox) Keeping backlight on - which pins to bridge on monitor psu board

Thought id seek a bit of pro advice from the forums for my first post as im totally drawing blanks on this one!. i am trying to finish my custom lightbox made from an old hanns.g hh281 monitor. at the moment, when powered on, the backlight turns on then off after a few seconds as no pc signal is being received.  i have taken a picture of the connector to the main board as i cannot figure out which 2 pins to bridge to keep the ccfl backlights on :-( i was guessing one of the ground pin and the on/off  would work but didnt want to mess this up on the first go . any input would be a godsend! thanks all!

Topic by Aikon359   |  last reply

Makey Makey Community Hub

We are stoked to be part of this new teacher community! Thank you, Instructables! We are going to have our own community hub soon, and are hoping you'll want to be a part of it! Do you have a Makey Makey guide that you've created for your classroom? We'd love to see it and share it on our hub! Share a link in this topic to show us what you've made.

Topic by MakeyMakey   |  last reply

whats the best way to open a laptop's ac adapter?

I have a Compaq v2000 laptop with a faulty lead inside the AC adapter's strain relief. I want to cut the cable and resolder it inside the adapter, but I need to get it open... it appears to be heat sealed (no visible screws, but a recessed plastic seam) what is the best way to open it up? btw, I'm quite comfortable working with large capacitors, before you ask. help?

Topic by gschoppe   |  last reply

DIY Scuba Tank (breath underwater)

I need some advice. I have a great idea that would be amazing if it worked. I want a small scuba/air tank whatever you want to call it (like a scuba secondary tank or a paintball co2 tank) that i can use to mess around with in a pool. I dont want to be constantly breathing, just enough to take a deep breath, go underwater and hold it for a minute, release air from the tank-take a breath, hold it, take another breath from the tank, hold it, and so on. Just enough to get a few breaths and be under water to last me for 5 or 10 minutes. The only thing is i dont want to have to fill it at a dive shop or from a tank that has to be filled at a dive shop like scuba secondary tanks. i want to rig it to fit a bike pump (which probably will not have enough psi to get the amount of air i want) or my air compressor. So i would like advice and also would i need an air regulator since im not constantly breathing? what could i use as a regulator if i need one at all? 

Topic by wdemarche   |  last reply

Premium Code

I received a code for a premium Teacher membership.  I have entered the code and logged in, but when I go to download it says I need to upgrade to premium.  Help!

Topic by Zilhaver01   |  last reply

solar light to laser beam ?

Hello, would it be possible to concentrate solar light so to form a laser beam ? In other words would it be possible to apply laser light principles to basic solar light with the help of optics of some sort ?

Topic by gabdab   |  last reply

Not able to access drafts

Whenever I click on the drafts button to edit my ice cream Instructable,, It sends me to the Instructables home page. Is this just a glitch or am I doing something wrong?Thank you!Wozzell11

Topic by Wozzell11 

Is it possible to connect an led in parallel with a lock mechanism?

I am working on a project. I have a keypad panel that unlocks a door and I want to add in the circuit an led indicator(when the lock is released I want the led to turn on. When connecting the lock with the led in parallel the keypad does not work properly. The lock uses 1amp and the led needs less than 350ma. Would a resistor on the led solve the problem? If yes, what resistor should I use? (it's obvious I don't know much about electronics but I wish to learn...). Any ideas or ideas or advice is most welcome! Thanks community!

Topic by DimiLa   |  last reply

Tesla coil antenna?

With the cold and bad weather out there I started again to tinker with my old UHF radio.Trying to build a nice antenna to put on the roof of the hous and such things...While looking up on the various antenna designs I could not help it and followed a few links with antenna designs and specs for all sorts of frequencies.There are things like horizontal or vertical transmission waves or even circular ones.But also some of the basics can be quite different, like whip antennas, dipoles or coiled ones.The later we often see in these keyfob transmitters and receivers for door bells and similar low range, low cost options.Some really old ham radio links got me to the topic or electrically shortening and lenghtening antennas.Things like coils in a whip or added capacitors to match the antenna to frequency and transmitter.A tesla coil usually produces a lot of RF interference, not just on the main frequency it operates on.And from research and physics we learned that for really great distances you need really low frequencies.Like for example the very low bands used for submarine communication around the globe.Here antennas on land can be several km long...The inventor had a few ideas in terms of wireless electricity and communication but I wonder if there is more to it...Despite the broadband EMF a tesla coil produces it is also a really narrow beam antenna.Basically the radiation cone is orientated straight up instead of the usual horizontal patterns we use for communication.The topload again provides a spherical radiation pattern.I am wondering about how a tesla coil would operate as a directional antenna if the topload is replaced with a whip style antenna of a lenght that matches the wavelength...The hip would again provide a more or less spherical beam but the coil underneath would "puch" a directional from underneath.In the classic design the topload is meant to prevent arcing while providing a capacitor so the whole thing is resonant.At lower power arcing is no problem anyways, but what effect in terms of capacitance would a whip style antenna have?Classic pherical or donut style toploads provide little to no gain in terms of antenna properties.If you would use a sphere as an antenna for your CB radio then it would be perfect for very short distance but utterly useless for open range communication.We all know the fun of placing a flourescent light near a tesla coil to show "wireless electricity".Sadly this is more an effect caused by the high frequencies be able to produce the glow in the gas filling.Trying to make an incandescent lighbulb glow is far trickier.Several experiments show that two properly tuned tesla coils can work as transmitter and receiver.But to my knowledge no one ever tried this type of experiment with an antenna on the tesla coil...

Topic by Downunder35m 

Need help simplifying project (Raspberry Pi + Pi Musicbox + NFC Reader)

Hello.I have a desire to build this project - https://github.com/brendandawes/PlasticPlayer.But I'm a total layman in hardware.TL;DR: Media player based on Raspberry Pi and Pi Musicbox (mopidy), with the Espruino + NFC reader used as a track selector (NFC cards store the track id which is then cross-referenced through a database).Upon close examination I think the additional Espruino is redundant (especially in the way author made it, so it talks to Raspberry via wi-fi), and I would like to connect it directly to Raspberry Pi.I've ordered the Raspberry Pi recently, and it hasn't arrived yet, so I can't really tinker with it. So asking the question ahead.Taking into account that Pi Musicbox will used as the base system, what exactly do I need to do, so that it can control NFC reader?How can I create a program to control Raspberry Pi GPIO? Is it possible to make it compatible with common libraries that are available for NFC reader?Thank you.

Topic by beshur