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


Overheating Car - Causes and Short - Term Solutions

Overheating of the engine not only occurs in the summer, but can also occur in daily driving. In particularly, high-speed running cars, engines, and air-conditioning systems can cause boiling phenomenon when the water temperature is too high. It's dangerous to overheat the engine. It may hard luck that what can damage the engine. When driving on highways at a higher speed, or when climbing a car, if the pointer of the water temperature gauge enters the red zone and stays high, appropriate measures should be taken at this time. Here's how to handle the engine overheating.There are many causes of overheating, including insufficient coolant, cooling fan cooling the coolant has failed, thermostat failure, and coolant temperature sensor failure. If you deal with it improperly, it can lead to an expensive engine failure. Therefore, timely detection and proper disposal of overheating can effectively reduce losses.First, poor engine cooling: Poor engine cooling can cause the water temperature in the tank to be too high. When longer the water tank is used, the more internal scale will build up, resulting in poor heat dissipation in the radiator. The water with too high temperature will not release heat, and it will evolve into a "pan". In addition, the ventilation hole of the radiator is also a common cause of poor heat dissipation. If the external blockage is not ventilated, use a water gun to clean it up. If the inside of the radiator is blocked, then clean it with a cleaning solution. Second, the cooling system is not working properly, resulting in poor heat dissipation. At this time, check the tightness of the fan belt and whether the fan blades are deformed or broken.Third, the thermostat automatically adjusts the amount of water entering in to the radiator according to the temperature of the cooling water, so as to ensure that the engine works within a suitable temperature range, which can play a role in saving energy consumption. If the engine is overheated, check that the thermostat is working properly. Starts at 70°C and fully open at 83°C. When the height of the fully opened valve is not less than 9 mm, the thermostat can be put into the water for heating inspection. If the thermostat can't be opened or the opening degree is not enough, the thermostat needs to be replaced.

Topic by violantez   |  last reply


Contest Judges Needed

Hi everyone! We need to update our judge list with some new names!To be eligible to judge, you must have posted at least ONE instructable. Let us know which contest categories you're interested to judge in the comments below: CookingWorkshopCircuitsCraftLivingOutsideTeachersThe judging process is fairly simple and involves looking at contest finalists and rating them on a scale from 0-9. Judging is open Friday afternoon through Monday night. Time spent judging is around 30 minutes to two hours - it all depends on how thorough you are!If it’s not a good time for you to judge when we contact you, no worries. We always try to assign more judges than we need in case something comes up.You can find out more about the judging process here.Don't worry! Judges are selected after finalists are selected, so volunteering to judge will not affect your chances of being a finalist in any contest you enter.Thanks for helping us keep the site awesome!

Topic by jessyratfink   |  last reply


What kinds of contests do YOU want to see on Instructables?

Hi everyone! As we're planning contests for the next year, we wanted to get suggestions and feedback on the types of contests we're running. :DIs there a contest we ran years ago you'd like to see again? Any contests you're sick of? A weekly challenge you'd like us to expand on? Do you want the contests to be more specific or more open ended?We're trying to shake things up in contest-land - so any and all suggestions are welcome! I'm especially interested in what types of tech contests you guys would like to see, as well as ideas for food contests. P.S. For anyone wondering about weekly challenges - we're still trying to figure out a way to do it that makes it easy for you guys to enter and easy for the editors here to run. But I promise we are discussing it! :)Have prize suggestions? Check this topic. Want to get a preview of some of our upcoming contests?

Topic by randofo   |  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


Removing Broken Pin from an RCA Jack

I recieved a free, working TV the other day. The only problem with it was the pin from an RCA video cable had broken off inside the socket. I didn't want to spend money on an RF modulator for my DVD Player, so I figured out a pretty solid way of getting the pin out. 1.) Find a needle 2.) On a hard surface, bend the very tip of the needle slightly so that it forms a tiny barb. 3.) heat the tip of the needle with a lighter until it glows red hot. 4.) stick the needle into the plastic core of the broken RCA pin 5.) wait a few seconds for it to cool 6.) pull the needle out, and the broken tip should follow!

Topic by spenjmn   |  last reply


Electronic Circuit- Help

Hello,My name is Daniela, I'm student and I need help to anyone who can help me :DProject goal: Control the temperature inside a closed chamberI need help to connect the all components and I don't know how because I'm new in this . I don't know how to amplify and to maintain the current, voltage so as to the whole circuit should work, what value is need for resistance, capacitors and other necessary components.I use a launchpad MSP-EXP430FR4133. I prefer to use power supply 3.3V (not 5V). To amplify the voltage I use a DC Boost Converter 2A power supply module MT3608 where the module output voltage can be adjusted.The temperature sensors it for hot side and cold side of Peltier element. A good size to have on the hot side is about 3 times as big a heatsink than on the cold side to don't find that both sides are getting hot. I have attached below a Block diagram, a List of Components, Description and What it looks like the final project. Please help me :D :) Datasheet: MSP-EXP430FR4133 :http://www.ti.com/lit/ug/slau595b/slau595b.pdfs FAN-BM5115-04W-B50-L00 : :http://www.farnell.com/datasheets/2266998.pdf?_ga=2.72941011.1375318338.1566287615-2140457824.1565329371 LM35DZ/NOPB :https://www.ti.com/lit/ds/symlink/lm35.pdf LMT86LP :https://www.ti.com/lit/ds/symlink/lmt86.pdf TMP112AIDRLT :https://www.ti.com/lit/ds/symlink/tmp112.pdf TEC-40-33-127 :https://eu.mouser.com/datasheet/2/433/Wakefield_Vette_Thermoelectric_Cooler_Full_Data_Sh-1501217.pdf MT3608 :https://www.olimex.com/Products/Breadboarding/BB-PWR-3608/resources/MT3608.pdf

Topic by Daniela1111   |  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


Login-Credentials BUG: Cookie Mishandling leads to possible website-vulnerability

I posted, Reposted and Re-linked over and over again. Nothing happened, not even a notification "we are on it" from the team.THIS IS A SECURITY ISSUE! People on a no longer logged in PC can see things they arent supposed to!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" - "Computer" which was the closest i could find to a website-problem... Geez...

Topic by Orngrimm   |  last reply


Vacuum tube amp help

I just bought a lot of 125 vacuum tubes on ebay for 30 dollars including shipping (the seller didn't list what tubes were there, just said a crate) I got the following (if the same name is listed 2 times in a row, then I got 2): 10JA8 12AD6 12AE6 12AF6 12AU6 12AX4GTA 12BD6 12BE6 12BG6 12C5 12CN5 12CU6 12J8 12K7GT 12RS 12X4 17AX4GT 17BR3 18FW6 18FX6 18FY6 1B3GT 1G3GT 1G3GT 1S4 1S4 1S5 1T4 1U5 1U5 1X2B 21LR8 2BN4 2BN4A 2CW4 2CY5 32ET5 3S4 3S4 3V4 4BQ7A 4BZ6 4BZ7 4BZ7 50B5 5AT8 5AT8 5AT8 5AT8 5BR8 5T8 5T8 5T8 5T8 5U8 5U8 5U8 5U8 654A 6AB4 6AF4A 6AG5 6AG5 6AL5 6AL5 6AM8 6AQ5 6AQ5A 6AS8 6AT6A 6AU6A 6AU6A 6AU6A 6AV6 6AV6 6AX4GTB 6BA6 6BA6 6BA6 6BA6 6BA6 6BE6 6BE6 6BJ6 6BK7B 6BN4A 6BN4A 6BN6 6BQ7A 6BQ7A 6BQ7A 6BQ7A 6BQ7A 6BU8 6BZ7 6BZ7 6BZ7 6BZT 6CB6 6CB6A 6CF6 6CG8A 6CN7 6CY5 6CY7 6CY7 6CY7 6DQ6A 6DQ6B 6EA8 6FM7 6GN8 6H6GT 6J6A 6J6A 6J6A 6S4A 6SA7 6SJ7 6SK7GT 6U8 6U8A 8FQ7 9A8 I'm thinking about making a small amp (below 5 watts) for my ipod, which one of these would be best?

Topic by guyfrom7up   |  last reply


Tempered glass screen protectors - understand and beware!

I recently had the joy of needing a new screen protector for my mobile after being dumb enough to drop it on gravel. The hard cover took all the impact but the film protector on the screen was scratched badly. Was old and partially worn anyway so I decided to upgrade to a Tempered Glass screen protector. Being somewhere rural I had no chance to get one in a shop so I ordered online. With no intention of advertising for some sellers, I collected a few links so you can check what I am talking about: Item1 Item2 Item3 Item4 Item5 Item6 So, what is my concern with these? They all can be found on amazon and other online services as well as on local markets... As I said I ordered a glass screen protector. If you check these listings and even some of the packing you will notice they all have a thing in common - being shatter proof and of 9H hardness. I also love this video showing how to remove and fix a glass screen protector! The last time I checked glass had one very distinct feature: It is hard and before it really bends it breaks - unless you use fibre optics of fibre glass cloth... What is my concern and warning here? Pretty simple: Stay away from expensive scams! Some claim their screen protector is only 0.25mm thick, even the 0.2mm one I measured was over 0.5mm with the glue... The hardness of 9H refers to the so called Moh's hardness - look it up on Wikipedia if you like. That means these tempered glass protectors would have a similr hardness than a diamond, or at least close to it. Problem is that they are made from plastic to start with and not glass at all. They claims that the screen protector is flexible because it is so thin - again a fake! Even the thinnest tempered glass will shatter if you bend it enough, not so these plastic ones. If you think I am making all this up try to use a really sharp knife or deburring tool and cut the thin sides of one of these protectors. All the ones I tested could be cut quite easy - and I though glass can't be cut with a kinfe... A nice website showing that the scratch resistance is far from the claims can be found here. And a video showing how a real glass screen protector sounds and breaks can be found here. So is it really all bad and should I avoid getting one? Not really if it is only for the added protection. To be clear here, and without the intention to blame any of the above sellers, some protectors actually do have a top layer made from glass and you can hear it as in the above video - it sound solid and not like plastic if you tap it with something hard. Another factor is the simple fact that plastic absorbs impact much better than glass. So where a real glass screen protector might shatter and crack like in the above video, the fake ones might one get a nasty dint or scratch. But you should be aware and clear about what you get and what to expect from it. These glass imitations are made from a strong polycarbonate plastic, similar to the stuff used for bullet and explosion proof "glas" windows - if you every watched the Mythbusters you have seen the big sheets I mean. The top layer of these things is specially treated to repell water, oil and dirt, it also gives the surface the good scratch resistance. The technique is nothing new, camera lenses, plastic sheets and the clear covers you see over the timetable at your bus stop all use it. The new thing is to intentionally mislable a product to make the consumer think it is glass ;) What is the real difference for the user? Check this video. Here a guy performs a drop test with a real glass screen protector. Thing is once the protector breaks the screen itself is broken too but until then it was not too bad. Here it is demonstrated how a real glass screen protector reacts to certain types of abuse - one of the reason I decided on glass. Compared to the plastic counterfeits just the sound on the glass is worth it, but I think the hacksaw was best. Another video from XDA gives a bit more info on how the glass is made - if you can't seeing a phone being abused then don't watch the drop tests at the end ;) Glass with these hardness levels and types of surface protection will give the user a long and worry free use of the phone. The plastic fakes will perform at a similar level for some time but will show signs of wear long before even the top coat of the glass one fails. Both types have their uses and if the fakes would be labeled correctly the user would actually benefit from that. On bigger screens like a tablet I would actually prefer the plastic ones to prevent damage once it needs replacing. On a mobile used in less than perfect conditions I would also go for plastic as it usually is a bit thinner and will fit better within quality hard covers. But when it comes to real abuse like using with dirty fingers most of the time or mostly outdoors where a lot of dust and fine sand can be involved I always go for glass. If you paid attention to the surface treatment then you already realised that the plastic and the glass are in the same region, making them quite scratch resistant. Still fine sand or metal dust will scratch it.... The difference is in the hardness of the actual material that was covered with the oleophobic film. Glass will not give in any way, where plastic is much softer - so not to be confused with the surface hardness! This mean that sharp and point object will easier penetrate the plastic than the glass, something to be considered if you often ecounter harsh use. In terms of actual protection we need to differenciate between surface quality and actual screen damage. After all when badly scratched we can replace the protector but if the display got damaged we are back to square one. The surface hardness was already covered so let's move on to the screen itself. In some of the above videos you can see the abuse a screen might see in normal conditions, and if we would not drop our phones so often repair shops would not be at every corner LOL I have done quite a few screen repairs, mostly for friends and work mates that did not want to pay the hefty extras in a repair shop. From there I got the stories on how it happened and in almost all cases the screen cracked when the phone landed on the corners. In one case the screen and glass protector failed, including the actual display when the phone was dropped out of a 4WD and landed screen first onto a rock. A glass protector will spread the (direct onto the face) impact force onto a much larger area, where a plastic one will produce a dint onto the actual screen much sooner. So again glass wins in terms of actually protecting your expensive screen. But be aware that all this is useless if the phone lands on the corners!! Let me explain: Both the top glass on your screen and the screen protector have a thin layer of "glue". This acts like a shock absorber, so unless an impact goes deep enough so the pressure on the actual screen is too much only the protector should fail. But the screen itself is a tight fit into the frame of the phone, so all side and corner impacts go directly into the glass. As the rest of the glass has no way to give or go the stresses will crack the screen. How should I treat my phone with the new screen protector? Exactly the same way you would without it of course. But if you don't have a proper cover that offers protection of the corners you should invest in one. Having a quality protector and a good case does not mean your phone can be used as a football, see it as an added insurance in case something does go wrong. For obvious reason it can also pay off to have a spare at hand, if something bad happens that requires replacement of the protector you won't be left with an unprotected screen ;) Last but not least, double it up: For people that already know their screen will see a fair bit of abuse in term of scratches it is a good idea to put an extra film protector onto the glass one. Once it is too scratched you peel it off and replace it, while the glass protector gives you the actual protection for your screen. Corning Willow glass As time of wrinting Corning Willow glass is the only "flexible" glass on the market, unless stated with your flexible screen protector you can assume it will be just plastic. I did not list it above as this high tech material is mainly reserved for displays and at least to my knowledge is not available for screen protectors, although I will stand corrected as I have to assume some big players use it for their protectors. The material is actually a sandwich where an ultra thin sheet of glass stis bewteen two layers of durable coating, read it up on their website it is quite interesting. It won't reach the strength of their famous Gorilla glass so without an outer plastic that has the additional oleophobic coating it won't provide the strenght of real tempered glass protectors. Some phones like the Galaxy Round and the fleixble HTC phones use it for example.

Topic by Downunder35m   |  last reply


Author Spotlight Interviews: Nominate an author!

We recently began a new round of author spotlight interviews. For the first interview, we chose to reach out and chat with Nikus, who recently won the grand prize in this year's Epilog Contest. You can check out our interview here: Author Spotlight: NikusThese interviews are a great way to learn a little more about individual contributing authors here on Instructables, and see what makes them tick! Is there someone who is an active author that you'd be interested in learning more about? Now's your chance to nominate a fellow author. There are no set requirements to be eligible to be nominated. But generally, we're looking for authors who've shared a good handful of high-quality projects, which made a notable splash within the Instructables community.And yes, if you're feeling bold, you may certainly nominate yourself! : )

Topic by seamster   |  last reply


Giving away a 3-month membership

Who knows? I feel like being nice today :DAnyways, Comment something nice about one of your favorite authors, someone who helped you, etc.That is an entry. One entry per person. On Monday, (tommorow), 3 pm, I'll pick one person to get a premium membership! Also, PLEASE don't enter if you've already gotten a membership. This is meant for people with no memberships only. Good Luck!

Topic by zakbobdop   |  last reply


Hacking An Alarm Clock

My sister (yes, the one for whom I made earrings) wants me to modify an alarm clock to run a small electronic device when it goes off. Preliminary research has given me two methods:1) A digital clock with a 555 timer circuitIn this setup, a 555 timer circuit is used to translate the signal to an alarm speaker/piezo disk into a relay. When the clock goes off, the relay clicks, and any electrical device that is run through the relay has power.2) An analog clock with a transistor amplifierIn this version, the analog clock seems to just have a straight DC output to the alarm. The transistor is used to amplify the DC to drive the motor of a fire bell.Which of these would be easier to implement? The device I am supposed to use runs off of 3VDC, so I was just going to run the power line through the relay or through the transformer.

Topic by CameronSS   |  last reply


Trouble with cover images for Instructables

I have been recently seeing this problem. Whenever I click an image upside down on my phone and edit it to flip to normal, it gets corrected and comes in the correct orientation. After uploading the image on the editor, everything looks fine, even after saving the changes, but after refreshing the page after a while, the cover image again flips upside down. If anyone has solution, kindly look into this issue.

Topic by KushagraK7   |  last reply


May 2019 site changes: my observations and thoughts

In early May 2019, Instructables' website has been radically reworked with a revamp. Changes I have observed include:Navigation: Many categories and subcategories have been eliminated and instead reworked under other folders as part of the changes (there is no "Play" category and subcategories such as "NERF" and "Paper Airplanes" no longer exist) "Recent" filtering is not directly available to people browsing the site--you must sift through the categories and get through at least two pages to find a way to filter the selected category for "recent" (i.e. Homepage -> Circuits -> Projects -> (Page at which you may select "recent")) There are no filters for searches On the front page and in the categories' main pages, featured projects are emphasizedThe Forum/"Community": Without manually typing in the URL, there is no direct way to access the "community" page Buttons to access the forum among in the category pages are tied to the community pages for that category (as a result. They do not allow you to see the general forum posts of the community without viewers manually deleting the category from the URL and going from thereThe way people navigate about sites controls what they can see and how they see if, so all of these things will change the flow and behavior of Instructables' viewers versus how it was before. Versus before, it is more cumbersome for viewers to get to recent content while featured content is more readily available. This will influence where people go and what they see.----------------------------------What do I believe this means for the future?Drawing on my decade of experience on this site, I suspect viewership of non-featured Instructables will drop. Thus, the viewership gap--between those projects that have been featured and those that have not--will then widen.Of these changes I think people will say you either "get featured or get buried."

Topic by OrigamiAirEnforcer   |  last reply


Bug: Page not found error for community topics

As the title states it seems to be impossible to load and topics here.....It also seems the old log out to log in bug is active again.Is it really that hard to provide a meaningful error message if the site kicked you out and you need to log in again?Sorry but I fail to see the point of appearing to be loggen in while half of the page fails to work thinking I am not logged in.Sure, loggin out, loggin in again and reloading the pages works - but am I the only one seeing this as annoying?And when you just think you made it then you get an error the site is appearently not available.Funny though that it is available for 99% of things, just not those you are currently working on ROFL

Topic by Downunder35m   |  last reply


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


Cloning the famous ARA-2000 antenna for SDR use

Several years ago the company behind the original ARA-2000 antenna, Dressler Hochfrequenztechnik, closed.The ARA series of antennas, like many other products by this company never got a patent, instead it was trusted that no one would bother to replicate it.A bit like the Swiss Army knife, many tried to copy it, none really managed to match the original quality.There is quite a bit of hacking still going on for this antenna, most projects though seem to be abandoned at the time of writing this.I am currently trying to figure out how to create an entire clone that everyone who knows how to properly use a soldering iron can build.There is a lot to consider here...The active element is of quite unusual shape and needs to be wound around a cylinder of a pretty accurate diameter.My initial tests showed that for example aluminium foil with some unavoidable wrinkles already has a negative effect.And a change in diameter of just 2mm means the entire antenna only performs badly for the entire band.This part is thankfully already solved to my satisfaction using thin copper sheets and some stiff plastic sheet.Quite a pain though is the MMIC part - the amplifier that makes the antenna active.There is a ton of MMIC blobs available, either solo or as a ready to go amplifier.Downside is that without really knowing any characteristics of the original is comes down to guesswork.And as most of the cheap SDR dongles won't provide a BIAS TEE I will opt for an external power supply for the amp.I might provide the option for a inline use a bit later though.Why clone the ARA-2000 antenna?For starters you need to forget the mythical stories you might have heard about this antenna."Picks up even the weakest signals!", "Totally linear over the entire bandwidth" and so on...Without the amplifier the antenna is actually not even average in therms of reception performance.My initial tests with a network analyser showed that the anteanna actually is behaving really weird (without the amp!).Although this first bit needs further testing, it seems that most, if not all of the work in the 1.5-2GHz range is done by just the straight connecting strup going from the amp, or in my test case the coax, to the wrapped antenna part.For anything in the more interesting frequency bands it seems that the antenna is not using anything like a discone, whip or ground plane antenna.Instead the 3rd harmonics of a given frequency provide the max power output from the antenna but it arrives at the cable at the right frequency.Especially in the lower frequencies, below 200MHz there is also quite some phase shifting happening.As a passive antenna it seems to be almost impossible to find a frequency to transmit on without using some matching trickery first.But when it comes to size or looks, the ARA outperforms everything you can think of unless you want to constantly adjust the length of your whip antenna.And if you check what is available in real (user) data in terms of noise and signal quality than most other antenna types are far worse.The design provides a wide frequency range with very little noise, almost like a build in filter.Considering that mostly harmonic frequencies are used not that surprising.Getting hooked on SDR means you start little and then you want more and more.Unless you really need the low frequency HAM bands below 50MHz the ARA is a good choice that just makes sense.What is quite surprising in the original is the total lack of protection for strong signals.Sure, we might never need a lightning arrestor because all is enclosed in plastic and has little attraction lightning, but someone hittiing the transmit button close by....I will have to do some more checks to determine whether or not more protection is required.What is the problem with amplifier?For starters, no one really knows what was used in the original - they all just guess based on how well the real design matches some datasheet.Means whatever was used might as well be a custom made solution.I checked a few datasheets for MMIC amps but could not find any useful reference to the handling of things like negative gain, phase shift or a constantly changing impedance.Some however state that a 50 or 75Ohm signal is provided at the output.If I interpret that correctly than those MMIC's not only amplify but also do some matching.In most cases you won't need an amp that works outside what the antenna can provide.Problem is that I don't like regretting things later on ;)So IMHO it would be best to use a wideband MMIC covering all from about 1MHz to a few GHz.Additional filters can then cut off what is not required or where the antenna starts to fail.What is clear by the original design is that the cable shield acts as a ground and most likely also has a balancing function.It would make sense to add a ferrite trap close the the receiver to filter out what the cable might otherwise mess up.Can the frequency range be lowered to get even the low HAM bands?The answer is YES and NO.It is not a big problem to extend the cone shape and then hope to come much lower.Issue with this is the helical, long periodic design.As basically only the 3rd harmonics are used for all interesting frequencies any ARA type antenna going much lower would end to be really long.You can't just make it longer!One thing is to have a full and even number of turns.The original only had two, three turns is bad, four means the entire antenna is slightly longer than your average downpipe for your roof gutters....Other, seemingly logical alternative would be to stick to two turns and to increase the diameter.Apart from the size problem here we would also change the shape of the foil quite a bit and I have not done enough tests with that to provide a conclusion.Are there alternative design options?As it turns out copper pipe is available in 80mm diameters for the use in chimneys as well as downpipes.With a proper machine it would be pretty straight forward to remove what is not used as the active element.Milling a pipe or rod is these days a common thing in many good workshops.But on a hobby level and low budget....One of the best options for cheap test antennas of this design is to use tinting foil - the cheapest you can find ;)Just read the lable and make sure it does not use a metalised film.If it has no UV protection and no tinit at all it is best but hard to find.A little less stiff is the stuff to cover school books or cupboards.Vinyl is bad though!If you look for copper foil in the cheap online places you mostly find the suff used for shielding in rolls of 200x1000mm.Unless you have a really sharp knife or really suitable sissors this stuff is a pain to cut as the glue tends to stick very good to whatever you use to cut through.Don't ever try one of these blade type cutters for paper and pictures unless you put a slight oil film on all cutting surfaces first....In some hobby shops you can get copper foil without any glue in different thicknesses - this stuff is the prefered option.Not only cheaper than the China rolls with glue but you invest a bit more and get a thickness that does not wrinkle right away when working with it ;)Cheap, steel downpipe and cutters or nibblers?I though about and I tried - and I failed LOLUnless you use a pin type nibbler and custom made rig the result is quite bad - at least mine was.What works though is to use thin aluminium sheets, cut them and then bend them around a suitable template.But I ran out of old laminated sings to salvage and the duble sided ones I have left are too much work.What comes next?Well, I have a few rolls of copper sheets coming next month, the cheap glue covered type.This time however I will leave the plastic cover on and use tape to secure the foil to the pipe.A two-stage amp with external power supply is coming too so I can do some more tests in this area.For the time being I will opt for some 3D printed end caps but with a bit of luck can find something easier next time I have time to waste in the hardware store.Excluding cable and a cheap USB or 12V power supply, the current costs of building the anteanna are around $40US.About half of that if you don't cennectors and attach the coax directly.Another experiement I am working on is to use copper tape, 12mm wide, to create the antenna in a semi-fractal style.I am hoping this will provide a high enough gain so the antenna is usable without an amplifier.Right now the biggest issue is to find a really SDR suitable way to deal with strong signal close by.I will keep you update here when I start with the new antenna and upload some pics along the was of building it.

Topic by Downunder35m   |  last reply


Can anyone make this Crossy Road Arcade?

Anyone has any source for DIY this Crossy Road Arcade? I did lots of research about this, but dont see any information about it. Looks like there is arcade version of this game and can not be found on internet....There is only one button for jumping, no joystick is needed.Can anyone DIY this arcade and share the instruction please?Thanks

Topic by rootloop   |  last reply


XPEDIT - Looking for Collaboration

Https://www.instructables.com/id/Xpedit-Device-for... For my upcoming adventure journey, i planned to build a handheld device that helps me to monitors temperature, humidity, air pressure, and altitude. Also, an alarm can be set for any of the parameters go beyond a user-defined threshold value. The device is powered with 1000maH lipo battery, with a backup of 72 Hours continues running! Consider this project for sensor contest, if it deserves! For the next version of this project, IAM looking for Collaboration, let me know anyone is interested!Edits : Collaborators welcome If you go hiking in your spare times, Any field of expertise are welocme if you are interested ...

Topic by DIYmechanics   |  last reply


GSM SIM800L Not Sending Value in SMS Alert When Triggered

Hi Team,please i need help in correcting why my code is not sending the current battery voltage value in the sms alert received. Attached is my code and picture of the sms alert received, once the threshold is reached, the gsm module sends an sms to my phone number but it does not contain the value of the current battery state/voltage; it only displays 0.0V in the sms rather.

Topic by jisaac6   |  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


# of published Instructables is wrong in Profile-Overview

As you can see, in the top right corner, it sells me: 1 Instructable published.If i check, i in reality have 2 (Main part of the webiste).Buggy buggy...

Topic by Orngrimm   |  last reply


An Other One

I have made a Plotter using 2 Stepper Motors from CD/DVD Drives.As so many have been done, not sure if the there would be interest on how I made this one.I have made the frame on my 3D printer, and made a circuit so the motors don't get hot enough to fry eggs on.Here is a video of it in action:

Topic by Palingenesis   |  last reply


Ring doorbell n/o quick short button press activate a push and hold buzzer for wharehouse

Existing buzzer in wharehouse need to connect to new ring type doorbell but I need to keep the buzzer tryed a new chime box wired inline, but it's not loud enough was hoping to be able to a circuit or device in line to run the buzzer for ten seconds or so when the short in the normally open bell button was pressed

Topic by john.ward   |  last reply


Treadmill control console

I need information about treadmills control consoles, how they interact with the lower dc controller and why they are not interchangeable with others from another treadmill as they perform the same job?. Thanks.

Topic by abuyaseen   |  last reply


Looking for a Fun Creative Project for Adults with Little to No Experience

I run a non profit teaching kids computer science concepts. As a fund raiser idea I was considering hosting an adult class at our local makerspace. I am looking for a kind of nerdy, somewhat inexpensive projects that adults will enjoy making as well as displaying in their home or office. With kids we do coding, make games, light LEDs with arduinos, make Raspeberry Pi cameras, and play around with paper circuits and homemade hex bugs. Does anyone have any adult ideas that may be fun? (Also, we are considering having a local brewery bring beer) I am open for more kids projects too, if you have any.

Topic by jkahle   |  last reply


HELP: Measuring power density from cellphone tower.

I am working on a project to measure the power density from cell tower. Most projects I saw involve expensive antenna and also a spectrum analyser which is too costly. I came across showing ppl fabricating a target single band microstrip passing through a RF Detector circuit. I think chip like AD8318 could handle it?? But how am I gonna filter if were to use an antenna with range of 200MHz to 2GHz eg. (https://www.sparkfun.com/products/8347) to measure a specific GSM band like 900/1800 MHz from the cell tower? I need help on the filtering and RF detector circuit part!!The closest resemblance to my proposed system: https://www.favoriot.com/category/how-to/

Topic by StudD   |  last reply


Need help making pop up speakers

So im trying to make a pair of popup speakers for my desk. I dont even mind it being pop up empty rectangular boxes (platforms) in which i can put in some portable Bluetooth speakers. I have attached a picture of a popup socket. Im not sure how it works though. I know you can use linear actuators but im not sure that will work or maybe i havent found the right ones. please if someone could help me

Topic by mmathavan   |  last reply


SDR antenna - 50 or 75Ohm cable?

Once you get going with your new SDR dongle you soon realise that it is little fun with the supplied antenna - if it came with one...Local stations, police (unencrypted) and so on is all fine with the short antennas.But if you want to get weaker stations or even track some satellites you are as lost as trying to get anything in the 160m band on your screen.Obvious way out is to get an external antenna.Depending on your needs and layout at home you might be lucky to find a ready to go option at some cost.In most cases though you will need more than the 3-5m that come with the usual antennas for car use.And not all base station antennas come with enough cable - keep in mind that hieght above ground and no obstructions close by count...With RG58 cable already being quite expensive a lot people consider the cheap 75Ohm TV cable as an alternative...Can we use 75Ohm antenna cable for our SDR needs?Of course we can!We only need to make sure that at the antenna end AND the receiver end the cable acts and appears like a 50Ohm cable.Especially if you need a really long cable in range of over 20m the TV cable shines with less loss that can't be ignored.Let me try to explain it the simple way first:You TV needs 75Ohm but the good old dipole antenna provides 300Ohm.The so called BALUN that connects the actual antenna with cable matches the antenna to the required 75Ohm impedance for the cable and TV.Like the TV, we don't transmit anything, so we don't have to care about what happens if power would go to the antenna - it is not a radio in the common sense, we just listen ;)There are many options available to match any impedance to any other but in our case a lenght of coax pairs is all that is needed.1/12 of the wavelength for the 75 and 50Ohm cable and we have a match.But.....You are right this simple option does not really work if you want to listen to a lot of different frequencies.What works fine for the TV also works fine on both ends!I assume you use an antenna for the common 50Ohm system and a standard 50Ohm SDR module or receiver.Two simple transformers will do the trick just fine and allow us to use cheap 75Ohm TV cable.The one on the antenna end provides 50Ohm for the antenna and 75Ohm for the cable.For the receiver the transformer is the same type but connected in reverse.You can look up how to make one with a simple ferrite torioid core and wire or coax but also order them from your favourite Chinese seller in the usual online markets.Add an antenna switch and you can use multiple antennas optimised for the frequency in question with dirt cheap TV cable.Just make sure to put the balun in a metal enclosure that is connected to the braid of the coax on both ends.

Topic by Downunder35m 


Principles of Laser cutting

I have being repairing all forms of cutting & welding machines for some years. In my experience for example Plasma cutters work on a principle of momentous arc. This is formed by a High frequency arc it only gives you 30 milliseconds to start your current flow. Air is required to force this arc out of the plasma cutting head. Ok got your attention now getting back to a laser cutter it also uses air to force out cutting light to cut or engrave. so looking for more under standing to work on a problem.

Topic by Keith MichaelD   |  last reply


Q: can i power a (9v-battery) multitester with 8 or 10v?

Hi, i´m living in a mountain-cabin with a small solar-kit (12v battery, 6 x 2v cells).i want to buy some multi-tester (which normally uses a 9v battery).i hate to buy batteries (and not just becauce i am a cheap fukc - might actually cost about a bit less than the tester itself, go figure, beauty/beast of capitalism)since i got anything from 2-4-6-8-10-12v here (for free - thank you sun): can i run the tester with 1 volt more or less? (or does all hell break loose .. which i´m actually kinda fond of)bowing

Topic by la xerra   |  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


Make use of iCamera 1000 units?

I have 3 "iCamera 1000" camera units laying around. I do not have the rest of the security system they are designed to function with, but there has to be some way to make use of them and have some fun. I have lots of cat 6 cable and RJ45 connectors to custom make a cable if anyone has the expertise to figure out how to make use of these. Before posting here, I searched and searched here and on Google but only found information regarding the "normal" application of these cameras..... I was hoping for something more outside the box which is why I am here. I included a front/back picture. Thanks for any ideas!!

Topic by PigWhistle   |  last reply


Suggestions for this post

Hello, i recently posted this instructable, please suggest tips to get better at this post since it wasn't featured and how to avoid those mistakes in future,thank you!

Topic by MissionCritical   |  last reply


Not able to open drafts.

Hi Team,I am unable to open drafts. Clicking on profile pic, its shows drafts, but nothing gets showed up once I click on it.Please help resolving this.Regards,Vineet

Topic by IoT Cloud Guru   |  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


Embedding Images?

Can anyone direct me to a resource on how I might be able to embed images in the text portion of an instructable instead of the standard way of just attaching them to a step by dragging amd dropping to the top of each step? I'd very interested in how the great mikeasaurus has been doing his Instructables recently. As an example check out this one https://www.instructables.com/id/Name-Puzzle/ That format just looks so much better for certain projects and if he can do it there must be a way.

Topic by TeacherMike   |  last reply


Relay with small in size

I have a relay with an Outline Dimensions:(15.5x10.5x11.8)mm 5V,3A--> Switching voltage 230VACDatasheet is given above..could you suggest the similar capacity with small in size (not a solid state relay) relay ??i was search website like MOUSER,LCSC .didn't find any suitable one.

Topic by shavanwe0   |  last reply


Solar charging

Hi, pls suggest me for the following A 20Watt ( 20V , 1000 ma) solar panel is connected to charge a 12V, 80AH battery . What is the value and wattage of a Current limiting resistor to be added?

Topic by khhrao   |  last reply


UHF CB radio antennas or scanner antennas anyone?

For a while now I am back to experimenting with various antenna designs for my UHF radio.Started as something entirely different but who cares LOLAnyways, we usually have either a standard whip antenna or a vertical dipole design for mobile use, like on your car.This is a very good design for both types of antennas, mostly due to the short wavelenght compared to the "old" 2m or 27mHz CB radios.Fun fact for at least AU in this regard is that back in the day everyone jumped onto UHF to get away from the overfilled chatter on 27MHz, now the old 2m band is basically dead except for marine use.One thing I really miss on UHF though is distance!Line of sight communication sounds fine at first but then you really have to realise the limits once out and about.As a result we often have to choose between a high gain antenna or a stubby for going into the mountains or being in a convoy.Only way out seems to be the golden middle by opting for one of the 4.5 - 6-5DBI antennas.Neither solution really satisfies me though :(To get around the limitations and have some fun again when sitting high on a mountain I compared various commercial antennas I had.You know, pick someone with a weak signal coming in and hope he hears you and has some time for a chat.Turned out there is not really that much difference in terms of receiving a signal.Quite huge differences though when it comes to the other side being able to hear you!So I jumped onto a basic SWR meter and actually checked my so called factory tuned antennas - all but one were way off the charts here.At least if you are like me and like optimised instead of compromised antenna systems.A Standing Wave Reflection ratio of 1:2 or even 1:2.5 is seen as very acceptable thing on UHF for some weird reason.Back in my glory days no one I knew would have accepted anything above 1:1.3 for his 27MHz system, be it mobil or a station at home.Sure enough, repeating my long distance tests a few days later with tuned antennas resulted in far better results.An antenna for long distance calls or emergencies?!The easiest way to get more distance on UHF is obviously getting the antenna as high as possible.From a nice mountain top you have it way easier than in any urban areas for example.Explains why so many of the long and sturdy antennas are just simple dipoles on a long pole.If you ever checked the feedback for these double quad TV antennas you realise they are literally in the same frequency range.Similar story for all the Yagi antennas for our TV sets that you find on so many roofs these days.Only problem with them is that they usually don't give a damn about transmitting qualities.And of course that they are usually providing around 300Ohm instead of the 50Ohm our radio expects.A TV needs 75Ohm and a balun is used to provide a isolation as well as a matching for the TV.Needless to say I could not accept this ;)My first design was made from aluminium foil glued onto some printed and stiched pages for a double quad.1MHz bandwidth is quite narrow, so the basic square design with about 13.8cm for the sides of the squares was easy.To my surprise by just adding standard RG58 cable this design was very close to 50Ohm already, I had around 60.A few glue sessions later I was able to match it to 52Ohm - close enough for test.Did not want to risk anything with my expensive Icom so I used my cheap Baofeng handheld for the initial tests.Indoor mind you...To me disappointment I seemed to be unable to pick up anything.So let the sanner run and waited...After being bored enough I decided to pick, starting with the antenna and when I moved it the handheld suddenly had a clear signal.Desperate as I was I grabbed the radio and waited for the chat to continue - nothing again...Then it finally hit me: The double quad is quite directional....Sure enough by just turning it slowly I was able to pick up chatter on various channels.Once brave enough to risk it I even got confirmation that people about 10km away could hear me just fine.Time to scale it up a notch...Next design already had the directional problem included as a design feature.I added a director in the front and a reflector in the back.The endless hours of glueing and cutting were replaced by using 12mm wide copper tape and sturdier cardboard.A test with my car on a little "mountain" and the antenna on 2m pole mounted to roof rack gave me, for the first time ever, conversations with people that were over 30km away.I am currently trying to make the entire thing omnidirectional.The omni quad....If you take two double quad antennas and mount them at a 90° angle you end up with very nice 2-lobe pattern, 4 lobes if you don't use a reflector.Problem here though is that these designs really mess with your antenna matching.Not to mention that using it while driving only works at quite low speeds.One day I will do the final design in stainless steel wire though...Anyways, using the directional properties to get an omnidirection radiation pattern meant using 4 seperate antennas with a reflector for each of them.Still left a few dark spots at short range but otherwise really nice for long distance if you don't want to constantly turn your antenna.Getting 4 antennas down to 50Ohm on the connection to the cable was painful to say the least.The problem of taking care of distances to be in the sweet spot for the 477MHz range also meant the design ended up to be quite bulky.One of my lightbulb moments providing good ideas caused me to use one reflector with a double quad either side.Worked almost fine but again provided totally different values to somehow match if it ever should transmit a signal without damaging the transmitter.Obvious conclusion was to buy a new roll of copper tape and to try to get four single antennas into one "housing" without stacking them.Bad idea here was to cross the antennas :(Better idea was to make 4 pyramids out of carboard and aluminium foil.Sadly this resulted in a failure because the 4 sides of the pyramid reflect the signal not flat bt at their corresponding angles.Had to make it really big and use 90° angles, resulting in the signal being reflected like light in these cat-eye reflectors on your bike.After wasting a few days to create the real thing it turned out to not really work properly for the reception already.Even close range signals came in really distorted.I guess the double reflection meant the phase is shifting and cancelling out what the antenna gets.My last desing idea for testing will be with a different approach.Instead of 1/4 Lambda elements I will use small 1/64 Lambda elements.Only about 2cm long means that matching is pain in the behind but if the purpose is just receiving it should be fine.The reflector will be four flat sides like a box with antennas in front of the sides and the cables joined in the center.If you like to fiddle with antennas and don't mind trying a weird looking base antenna on your roof I might be willing to write up a short Instructable based on my designs - let me know in the comments....By the way: it is quite easy to desing this for the common 2.4GHz Wifi bands ;)

Topic by Downunder35m   |  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-restarts As 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 seems And 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


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


Last update make this site pointless.

Tanks for making this site pointless by removing RECENT option.

Topic by gonzzo   |  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


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


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


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


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