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Topics


How Would You Fix This?

I've watched videos on YouTube about it and have never done body work before. So I'm trying to soak up as much info as I can from as many sources as possible. It's hard to find forums that are updated frequently so that's I'm posting on here. Can anyone suggest how they would go about fixing this type of rust? The more detail the better, thank you.

Question by MustLearnStuff    |  last reply


How much water is in my cistern?

I built a 33 gallon cistern my garage to collect condensate from my HVAC system. (I didn't have room outside my condo for a rain barrel). It has a spigot and a short hose, it lives above my utility sink, which is where the overflow goes when the cistern is full. I'm hoping some clever makers can give me some ideas on how I can build something that will tell me how much water is in the cistern. I have Samsung SmartThings so I've considered putting a water sensor just below the overflow hole, so I will know when it's at 100%, but I would prefer to have a percentage reading and an alarm when it gets to 90% or so. I considered an arduino with an ultrasonic sensor but that a bit involved... Not opposed to it but please be prepared to hold my hand thru the process of you propose it! ☺. Non-SmartThings solutions also welcome.Thank you - looking forward to your genius ideas!!Mark

Topic by MarkB673    |  last reply


What does DZ stand for ?

I would like to know what DZ stands for in a wiring schematic. Could it be diode Zener? Although I thought that was just Z?

Question by wesfourwood    |  last reply


How to view the retina of the eye?

Hello everyone ,I viewed the OIO model but I am trying to do a slightly different method. I have a 20D lens and IR camera with raspberry pi . I have a problem viewing the retina of the eye . To be more precise the imaging of the retina in IR camera without pupil dilation is much difficult for me . I tried different angles in a dark room but still I can only view the anterior of the eye and the posterior is not viewed . Hope you understand the problem I am facing , can you help me in taking this project further ?

Question by Ramya97    |  last reply


How to Use a Single Half-Bridge Micro Load Cell for Weighing

Hello,Could anybody please tell me how to use a Single Half-Bridge Micro Load Cell along with an Hx711 module, Arduino Nano to make a weighing scale?I've attached the kind of load cell I'm using in the attachments.Thank you.

Question by akshaykkumar    |  last reply


My arduino bluetooth car is not working, how can i fix it?

I have made bluetooth car using arduino but im having a problem using bluetooth serial how can i fix it here are the code that i have written #include AF_DCMotor motor1(1,MOTOR12_64KHZ);//running motor on full speed of 64Khz AF_DCMotor motor2(2,MOTOR12_64KHZ); int led = 13; void setup() { //Put your setup code here, to run once: Serial.begin(9600); motor1.setSpeed(255);// default speed motor2.setSpeed(255); pinMode(led,OUTPUT); } void loop() { //Put your main code here, to run repeatedly: if(Serial.available()>0) { int incoming=Serial.read(); if(incoming=='f'){ motor1.run(FORWARD); } if(incoming=='b'){ motor1.run(BACKWARD); } if(incoming=='l'){ motor2.run(FORWARD); } if(incoming=='r'){ motor2.run(BACKWARD); } if(incoming=='o'){ digitalWrite(led,HIGH); } if(incoming=='c'){ digitalWrite(led,LOW); } } }

Question by Tkt creative  


Tips and tricks for UV curing glue, resin and coatings

Only a few years ago your only option to repair certain plastics, glass or even a broken crystal was epoxy based resin or the good old superglue.You might have already tried one of the 5-seconds-repair pens or tried your own UV curing nail polish art at home.For the later you might be lucky as the resins used here are optimised for the purpose and lights you get with them.Sadly even the best nail polish is no substitude for a glue as the material properties need to be different.One of the most common complaints when it comes to using some UV glue, like Kafuter or similar is that it never comes with instructions.Sould be straight forward but it is not free of problems.For example almost all commercail UV curing glues that you can buy require quite stirct procedures and for the light the right wavelenth(s).Resins and coatings can be even more painful here as they might also require you to stick to the correct temperature.Let's start with one thing you might have encountered already...The glue is definately cured and rock hard but the surface tacky and smeary.Quite annoying if you want to fix a piece of jewellery and can't prevent it from collecting dirt and dust...The next thing you might have encountered is that despite having transparent materials it seems to be impossible to cure the clue.Both problems come down to wavelenght and exposure.UV curing glue is prevented from curing in the presence of oxygen - a factor utilised for example in resin based 3D printers.Uncovered glue is exposed to the oxygen in the air and won't cure easy.The glue or resin below this layer however with fully cure with ease in the absence of oxygen.For the second problem consider that not all materials that you can see through will let UVC light pass through ;)Bonding strenght is another complaint I hear a lot...Be aware that certain things just are no good for UV curing glues or resins.Take the molds you get for that purpose: on the material the glue won't bond!Teflon is another prime candidate here.But in a lot of cases it comes down to surface preparation.Don't be afriad to sand the surface!Not only will the surface area increase but the scratch marks will be invisible once filled anyways.Use sandpaper on your fingernails, then go over with clear nail polish -mirror finish ;)With curing often a problem consider to fully cover the glue.A bit of clear sticky tape, food wrapping foil....If that is not an option then eliminate the oxygen.You can use a container filled with inert (for the glue) gas like CO2 or just place a burning candle in it until it goes out....Either way the amount of oxygen should then be low enough to cure the surface of your glue.Not always is any of the above an option.Then you can still try more power and a lover wavelength.Mercury based lamps for example provide a very broad and powerful light that in most cases will cure within seconds.For a proper surface cure you need a wavelength of 265nm or lower.LED's offering this exist but at prices well out of range for the hobby user.A mercury lamp under high pressure is nothing for short term use and the limited lifespan does not always justify the costs of buying them.Like with most things in life certain inventions can have a dual purpose.Quality germicidal lamp systems for examples often state to go as low or even lower than 265nm.And they come at a fraction of the cost you have with a broadband mercury lamp.Even cheaper is the fre weather forecast.If the sun is siad to be strong enough so you need protection than even the worst glue will fully cure in seconds outside in the sun - tackfree!Don't be fooled and protect yourself!!These tiny LED lamps for your glue stick, the curing thingies for your nailpolish and everything else using UV light comes with warnings.For very good reasons!It might be hidden in the fineprint but you can not really see UV light.The blueish-purple glow you see is on the high end of what comes out and by that in the visible range of your eye.Just because a LED only gives a faint glow you see does not mean the UV light wouldn blind you if you could see it!Even worse for fluoroscent lamps or open cruning systems like those for your nailpolish.Reflected UV light is still UV light and you can still NOT see it!Stories of people getting sunburnt from germicidal lamps in a butcher shop or other people going blind from checking money as their living have a true base...In most cases lamps used well past their lifespan or simply the wrong type of lamp but still: the damage came from UVC light...If you just love creating your own artwork or jewellery with UV curing resins and glues than protect yourself.Proper sunglasses with a stated UV protection for example or just black nitrile gloves for your hands...

Topic by Downunder35m  


Teacher Account

Hello, I am a teacher at Stuart Hall School. I would like a pro membership so I can utilize all these great projects in classroom. I teach at a private school so my email does not end in edu. Here is the our website: http://www.stuarthallschool.org/ Thank you!

Topic by kgcarini    |  last reply


Wireless Communication Answered

I want to make some small cheap (possibly from toys) walkie talkies it would also be handy if i could attach some headphones(with inbuilt [eg iphone headphones] or seperate mic) im hopeing to have signel ~100-500m but anything will do.

Question by s117    |  last reply


InVision LD 3D Printer Help

A 3D printer has been donated to my classroom for a few months, but we were not given any documentation on the printers use. I have looked online, but it is an older 3D printer and information is lacking. I thought I would see if anyone here had experience and could point me in the right direction. I have been to manufacturer's website but have had little luck since it is a legacy system. I have looked online but I cannot find a manual. If I could find a manual that would help greatly. It is an InVision LD 3D Printer, S/N 05JA1921 Thanks!

Topic by ehudwill    |  last reply


Does peeling make tans go away?

I got sunburned and it became a really nice tan. But now it's all peeling. Will the tan go away after the dead skin peels away?

Question by rushfantomsawyer    |  last reply


What is the most affordable laser cutter for a beginner?

I really would love to try out laser cutting. ..But have no idea what knowledge it requires. I want to be able to design and cut custom wooden puzzle, laser cut fabric and also to cut felt and foam. I would like to start up a small home business. Keeping in mind that I have no clue what knowledge it requires and also know that I have 4 kids and will have to have this machine in my home. I do own a silhouette cameo but unfortunately it does not cut felt or wood. It’s a fun machine for cardstock and all…but nothing heavy duty. So is it safe to have a laser cutter at home with kids?? I mean will the light or whatever that comes off the machine be harmful for my children? Also how much is the cheapest desktop version? Will it be able to cut large fabric? Can it cut 0.5” or 0.75” hard wood?? Would that be pushing my luck?? Please let me know…so I can start saving up for it. I really really love crafting….but availability of items and affordability is a big issue. Thanks!

Topic by shazni    |  last reply


"I dont know but iv been told":Calling Cadence

My soccer team dose lots of running and we'v been trying to find some of the: I dono what iv been told lines, the ones the armed forces sing when they run in a group (at least i think they do but i have no exspirance). the lead runner says "I dont but iv been told" a response from the rest of the group would be "the sun shines bright but im still cold" so if you know one or two lines please just comment and ill put them up for me and any one elce that needs verses. or if you find a websight that has lists of lines please post a link (yes i have googled it and no didnt find any)

Topic by i make shooting things    |  last reply


Add Frets to a Violin?

I have a violin and i play guitar. I want to learn violin but it's the concept of no frets i cant grasp. Could i add some with pipecleaners or something? Suggestions?

Question by PyroMaster007    |  last reply


Why these relay issues?

In my PCB ,AC voltage is passes under the relays(R).. relays too become heat up.

Topic by sforsajith    |  last reply


Hack Needed: Rechargeable Halogen Spotlight

Greetings all, I'm in need of a hack to replace the lead acid battery in a rechargeable halogen spotlight purchased at a local store. The spotlight came with a AC recharger but 15 charge time hours returns only approximately twenty minutes of usable light. I'd much like to replace the power source with something of a longer duration than the current one third of an hour. As much interested in simply rewiring the device to work from my car's AC outlet if possible. Mind I only have a few dollars invested in this device still I'd like to see if a replacement power source is worth the effort. Thanks to all who reply.http://ledmuseum.candlepower.us/third/fixit.htm

Topic by patron_zero    |  last reply


Is it possible to make a solar powered diffuser jewelry that emits steam with miniLED light

I have come across instructables that I wanted to combine: the homemade solar cell using household materials which can be found here, the LED jewelry that can also be found here, and lastly, doing the diffuser procedure which is actually just adding the essential oil on the boiling water. it's like making a ministeam boiler but worn as accessory. I need help with this? Thanks! I think it would involve calculating volts converting the equivalent solar cell measurements to the most smaller measurements as possible. And also how long would the solar cell can be able to sustain and how many volts do I need to reach boiling point? Thanks! I will be updating as soon as I can gather and connect these things. Accdg. To my research, to water to reach boiling point, a 1kg water = 1,200 joules/min. Or 1,600 watts. I wanna know how many watts or volts in order to boil a 1ml water?

Question by Sleemakes    |  last reply


Is it possible to use Piezoelectric sensors to measure weight, like a hypersensitive set of scales?

If Piezo is not appropriate in this case, which would be the best technology / method of weighing to use? I want to create a a hypersensitive set of scales which read up to 1 kg of total weight. But I want to create it as flat and flexible as possible. The footprint would be roughly 115 x 55 mm and be used to measure the weights of small foods for the prupose dieting, can anyone help me?

Question by oscarpf    |  last reply


Be your mechanic

Hello to all the magnanimousStudent professors and those who work in their own businesses Do not be tired of your loved ones. My name is Amir 48 years old and I have almost 32 years of experience in mechanical testing of cars in Tehran. I'm very interested in electronics and I repair almost 70% of my belongings But I did not attend classes in any classroom that I learned early. I'm glad to be among you I'm also happy to be in touch with mechanical questions Thank you

Topic by aryyyya1349    |  last reply


Building a current booster circuit

Need to understand whats going on in this circuit which is a class project.

Question by ighalo_joshua    |  last reply


Attiny84 is not working and frezes

Hallo,i have uploaded the program for several Attiny84, some of them working perfectly and the rest are not sending any signals. i checked the Fuse sitting, it is right because i compared with the other working attiny. i tried to upload the program by Atmel studio 7 much times but it is not working. i can see from atmel studio that the program uploaded and the fuse sitting is right my experience in AVR is not really good. could i someone help methanks in Advance

Question by chabs123    |  last reply


Cats meowing all night, please help!? Answered

I am having issues with my cats meowing all night.  They are definitely indoor cats, and won't even go out a wide open door.  I have made them a spare bedroom up with all their needs and toys.  When I used to let them run the house at night, my female would keep me up all night jumping on the bed and me.  I tried closing the door to keep her out, and she just cried all night and clawed at the bottom of the door.  I made up the room and put them to bed at night, and she screams and keeps the neighbors and me up.  I have not had a decent sleep in too long!  Worse, she has taught the other cat to scream all night, and the neighbors are complaining.  I have tried to stop spoiling her so much, and I think she has separation anxiety.  I am gone at work all day, and my husband even longer.  I do play with her in the evenings, but it never seems to be enough.  If I have to get rid of them both, it's unfair to the calmer cat, and then most shelters will put them to sleep, besides the stress they will go through first!  I am out of options and nearly out of time... Please advise!

Question by hishealer    |  last reply


Electric Ukelele & Viola, Violin or Octave Violin Build

I am searching for inexpensive means to create aesthetically pleasing electric stringed instruments. I started this project when I started playing viola years after I was forced to quit private lessons. I discovered the F-f-fiddle on openfab.com which is a super rad 3d printed electric violin but since I do not have access to any 3D printer in the tiny town which I reside in, I sent the files to an online 3D printing business and they quoted me at least $500 just for the Fffiddle body! I didn't even bother to ask for a quote on the electric ukelele which I want to print & build so badly as well. I am interested in this project so that I can possibly help low income public school students in creating their own instruments to inspire them to take up an instrument and show them how much fun it can be to create something by yourself rather than buy. I am especially interested in acrylic plastic/lucite/celluloid, resins, exotic wood, recycled plastics, plastic injection molding, piezo pickups, and any other interesting materials that could be incorporated into these projects. I have been studying luthier tools, supplies, etc, along with design/fabrication of lucite/acrylic stringed instruments, furniture and other home goods. 3D printing/scanning, vintage celluloid guitar finishes, pre amps, recycling plastic bottles, landfill harmonic instruments, leather, pearl inlay, metallic finishes, enameling kilns, metal smithing, hand engraving & everything in between. I have been a mixed media artist for nearly my entire life and my father was a jeweler. I am going to find a way to create some functional and beautiful instruments no matter how long it takes me to narrow down the right combination of materials and how to make them, model them, mold them, dye them, etc! The photos attached are simply inspirational photos which I have collected over the past 6-8 months. Many of them are possibly patented, licensed, etc and I do NOT want to simply RIP OFF any of these photos! Please email me at svbacklund@gmail.com if you believe you could help me with my low income student instruments program or leads on 3d printing grants for public schools or anything else that may help me on my latest project or contact me directly via my instructables question here. I especially am interested in creating an electric violin which incorporates both classical and contemporary design. Any advice? Could you help?

Question by SVBacklunda    |  last reply


Attach Pasta Maker to Kitchen Aid Mixer

Can someone come Up with an easy tutorial on Attaching a Pasta Maker to Kitchen Aid Mixer ? The Pasta Maker has a Manual Cranking Handle. I have seen Kitchen Aids with the attachment and would like to convert mine.

Topic by TheCritic    |  last reply


Equalizer for phono input to amp

Circuit for converting an MP3 player output to input for a phono input on an amp.

Topic by knorrisster    |  last reply


Help. Using Arduino as a pressure and voltage sensing switch?

Could use some assistance here.Required: An activation switch that relies on two pressure sensors and a voltage sensing input and a manual activation switchI am trying to use an arduino as the mastermind to activate a relay based on 3 inputs; 1200-1500psi transducer, 40-60psi fuel pressure sensor and a 4.8v max throttle position sensor.The Arduino once receiving an input from my arming switch, will check the sensors/inputs and if values are met will send an activation voltage to the relay, which will in turn activate my nitrous oxide and fuel solinoids.I may consider adding a small LCD to show what is ready and if the system is armed and activated.[Arm Switch]----》 [Arduino] [Checks]----》[Fuel Pressure Sensor]----》[ready/not ready] [Checks]----》[N2O Pressure Transducer]----》[ready/not ready] [Checks]----》[TPS voltage (4.8v=wide open throttle)]----》[ready/not ready][Arduino (if all ready)]----》 [Relay is activated]

Question by MrB36  


Pic18f452 generic board

I built a generic board for pic18f452 microcontroller. But i am not sure if it is working or not.it is getting Vcc=5Vits reset button is working(i.e gives 0V on pressing)i want to know about how to be sure that this generic board is built correctly.

Question by asif.haris21    |  last reply


Can I power a Nintendo Wii with a 12 volt lead acid battery? Answered

I've decided to make a (somewhat) portable Wii, and I'm hoping to use a 12 volt 7AH battery to power it. The batteries will be attached directly to the power input on the console (with a filter cap). Here's what's been bugging me, though. The Wii's normal AC adapter puts out ~12.2 VDC, A sealed lead acid battery, however, puts out 12.6 when fully charged. Will that 0.4 volts do anything, or am I just being a nut? If it does, can I shave off that 0.4 volts with anything?

Question by Shagglepuff    |  last reply


Need Help in Building DIY LiFePo4 battery pack

Hello all, my wishes to everyoneam very new to this Electrical, Batteries and DIY, with the help of google i can gained little knowledge with that i could able to gather products to build my own electric scooter (1500W 60V HUb Motor and 60-72V regenerative controller with Daly LiFePO4 60V 45A Comm BMSactually am planning to Build 60V 36Ah LiFePO4 Battery Pack Using 19S6PBattery : LiFePO4 32650 3.2V 6Ah BMS : Daly LiFePO4 60V 45A Comm BMS Controller : 60-72V 1500W 35A am confused when times comes to assemble the battery pack, pls help and guide me with appropriate diagram or chart for 19S6P pack, help me how to connect batteries in series and parallel along with BMS so that i can build my first battery pack with out no mistakes Do i have use capacitors while connecting batteries, if so provide me the type already bought the battery tab spot welder from my friend for reference i have attached pictures of the products i mentioned and bought already please don't mind if i asked too much help/suggestions, want to make my own DIY battery pack by learning ad gather information about battery pack and build one one in perfect way Thanks in Advance

Topic by tejeyes  


Not Able to Get to Drafts - Help!

Hey all, I haven't been able to access my draft 'Ibles for a few weeks. Whenever I click on the "Drafts" link it takes me to the Instructables home page. I can see all of the ones I have published, but as soon as I try to flip to drafts it redirects me away.I was able to finish up and publish my last project by finding the Editor page in my browser history, but I can't do that for other ones that I haven't opened since I got a new computer.Is this a bug that's been going around or is there a different way I should be accessing the drafts?I appreciate the help!

Topic by BakkerJo    |  last reply


Need help identifying a capacitor (from a drill that exploded in my face!) SOLVED

Help! I am incapable of identifying this capacitor.The capacitor says KPB 7301 B9 0.15 μF +2x 2500 pF XY 250V~, and I'm not entirely sure what this means, and what I need to maybe buy to replace it. is it a .15 microfarad one, two 2500pF in one, or both?While drilling a small hole in aluminum, the drill suddenly made an insanely loud explosion sound. Freaked the spinning drill bit out of me. I took it apart and found this exploded capacitor I need help identifying, to replace. It's an old drill that also powers my mini circular saw and bench grinder, SKIL 1437 H1.Thanks!

Question by Yonatan24    |  last reply


DIY BBQ grill

Hello, I'm building a BBQ from an old 20ltr water boiler. I need to make the grill (where the meat goes). I'm thinking about making it from rebar. Would this be safe? I looked to buy one premade, but don't find one the right size

Question by MaDoGK    |  last reply


How can I balance a wobbly ceiling fan without the sticky weights that come with it?

I do not have the balancing kit that comes with new fans, and I don't want to glue washers to the back of the blades. Is there a better way to balance a ceiling fan without a kit?

Question by ivyplant    |  last reply


Can you cut glass with a hacksaw blade ?

For example: opening of 4 feet fluroscent tubes.

Question by krk1948    |  last reply


Single remote control button for grandma

Hello,I am trying to turn a remote controlled socket remote control (which comes with 4 on and an off buttons) into a single button remote, so that when pressing the button the light would go (on/off/on/off etc.) I am putting this together for a friend with limited mobility who is having issues pressing the on and the off button independently and was wondering if anyone could help? My knowledge of this is incredible limited, so apologies if this is a super simple solve. The current remote (seen in the picture) has a frequency of 433.92MHzThank you!!!

Question by luruca    |  last reply


Need help to power an LCD

So recently i salvaged an LCD from my broken head unit. It is a 6.5 inch screen i think. I really want to put it to good use because it is still in perfect condition. It even came with touch screen (it is pressure sensitive but meh at least there is something). Maybe someone here can help me to get picture to come out of the screen. Maybe a control board or something that have hdmi or vga input. I have included a pdf file about the screen :) Everythig should be there. Thanks in advance!

Question by piece of potato  


Home Page Images

The images for "Explore Projects" on the home page never seem to change. Repeat viewers could be excused for thinking that nothing has changed on Instructables between visits.How hard would it be to update the images on a daily basis ... using perhaps a random function?PS: This post is likely to be missed by viewers in other "Categories" and "Channels" as the posting options are too restrictive.

Topic by lingib  


Get an error when saving instructable published yesterday.

Don't know what I'm doing wrong. I'm trying to add another step. So, I add the step and then try to save it and this error message is what happens...Here is a screenshot of the error message.The only way to remove the error is to remove the additional step.Here is the link to the instructable which I am trying to add another step....https://www.instructables.com/id/A-Shorted-Motorized-Transformer-Simulated-in-Micro/

Question by Vinyasi  


Unable to view comments

I'm unable to look at my list of comments - if I click on ...https://www.instructables.com/member/Kiteman/discu......I get sent back to the front page.Anybody else?

Topic by Kiteman    |  last reply


Can't access my Inbox on Instrucables

Is anyone else having issues accessing their inbox on the site? Every time I try to open it it takes me back to the home page. The issues been happening for awhile now.Anyone know a fix or how I can get into it?Cheers

Topic by lonesoulsurfer    |  last reply


Wordless how- to videos.

Https://m.youtube.com/watch?v=r0oX4I11BMc This is not my video, but I thought it was pretty cool. I really like some of these wordless how to videos. I suppose that it assumes a certain familiarity with the processes from anyone who would do these projects. Yet, if you don't have a familiarity with welding for instance, you probably wouldn't do this project anyway. Any other good videos like this one?

Topic by Toga_Dan    |  last reply


How to turn .STL files into .SVG files?

Im looking to laser cut a part but i need to figure out how to get a cross section file saved as an SVG file. I made the part on inventor, exported it and then tried to upload it to 123D design but it wont allow me. What do i do?

Question by LancerRobotics3415    |  last reply


Mystery (to me ;-) Succulent Identification: What is this? Answered

I bought this really interesting succulent(?) from a door-to-door plant salesman a week ago.   The pot is 5", so that gives you a size reference.  This strange-growing plant appears to have thorns, but the spikey protrusions are not hard or ouchie-sharp. Does anyone know what species it is?

Question by bajablue    |  last reply


Need HELP! Dwyer Love TCS Controller- Temperature probe

Recently replaced a new aquastat for wood boiler and thermocouple. The new aquastat is a TCS-4010 Dywer Love controller. I have tested 2 different thermocouples and it appears the input for probe wires isn't detecting the thermocouple and creating a buzzer alarm with 000. Is this common to have a faulty controller new, off the shelf?Aquastat: TCS-4010https://www.grainger.com/product/product/LOVE-115V...Thermocouple- https://www.grainger.com/product/TEMPCO-Thermocoup...Thanks!

Question by bryanholcomb23  


Trying to give membership to a friend, where to enter the code? Answered

I'm sorry, I've looked all over the site, and even Googled key words, but keep finding broken links. I'm trying to give a friend a code for a free membership, but the site keeps asking her for credit card info. I understand the site has been changing lately, but I'm stumped as to how I can help her get the membership logged, and start creating Instructables. Many thanks!

Question by WUVIE    |  last reply


PDF's are 0 (zero) bytes

I am a 'new' Pro Subscriber. I tried downloading .PDF from this posting using Firefox (and Chrome);https://www.instructables.com/id/How-to-program-arcs-and-linear-movement-in-G-Code-/The files are zero bytes. What's up with that. What's the solution?

Question by squattingdog  


Help repairing a pair of headphones

First things first, they look like Beats, but I’m pretty sure these are knockoffs. Nonetheless, they sound pretty good, and I picked them up at Goodwill for a steal and love a challenge, so if someone is interested on taking on this electronics mystery with me I’d be incredibly grateful.Context: I’ve tinkered on and off with consumer electronics for a while now, am okay at soldering and have an okay knowledge of how more basic circuits work. Otherwise, I'm pretty beginner but generally a quick learner and would be happy to try any of your suggestions. The previous owner attempted to replace the AAA battery holding component with a rechargeable lithium ion battery - only problem was there was no way to charge the battery. Not a huge deal, fixed the headphones to run on AAAs again as they were originally intended. That said, pressing and holding the power button powers the headphones on, but also is the Bluetooth connection button on the board (image at the imgur link below) there is an icon for both the connection functionality and the power around the same button. The headphones power on, work, and sound great when you're holding the button down, but once you let go they turn off. So, it’s a momentary switch with no latch to keep it held down - not ideal. That said, I’ve tested jumping the switch so it gets constant power without holding the button down, and while the headphones power on, connect to my phone, and work, because it seems the power button and bluetooth button are one in the same, the headphones continue to look for Bluetooth devices and makes a periodic and infuriating beeping sound about every fifteen seconds. Based on the pictures of the board below (pictured with, and without button attached) can anyone figure out what the problem might be? Or point me in the right direction for further tests to run?Front of the board, with buttons.Front of the board, with power/bluetooth button removedBack of the board, held upright with power/bluetooth button side up

Question by WarpStar  


How to size a DC motor? Answered

I want to rotate a stainless steel shaft that is in a vertical position having a 40 mm diameter and 300 mm length. The motor will be attached to the bottom of the shaft, so when the motor is turned, the said shaft will rotate. The shaft is not driving anything, it just turns on its own. The shaft's mass is 3kg(according to my calculations).  I want the shaft to rotate at an angular speed of 45 degrees per second. Having this information, how can i size the motor that will do the job. What kind of torque would i need, what kind of wattage. Please show me some calculations so I can know how motor sizing is correctly done.  Very much appreciated, Chris

Question by Chris414    |  last reply


Calculating my DC motor

I'm not sure on how to calculate the things I need. Please help!!!!Pulley Radius- 5.85mmMass(load)- 0.2334 kgVolts- 9VCurrent- 0.096ASpeed-112.4rpmForce-?Torque-? Power-?Power Out -?Efficiency- ?

Topic by hj212121    |  last reply


High efficiency coilgun design

Hello there I need some (a lot of) help with my project. I've started to design a high efficiency multistage coilgun. The main feature of the design is using the self-inductance formed in coils that were shut down for accelerating the following coils. To perform this, we can divide each coil into 3 segments (lets call them subcoils), connected with a wire and power all them 3 with a single capacitor. At first, the current from the capacitor is flowing through all 3 segments and a projectile is being pushed through the first segment. Than the first sensor is being activated with the projectile and it switches the power flow to only second and third subcolis As the current in the first subcoil is changed, the self-inductance directed in the opposite direction is appearing. In theory, we can use this power to increase the current in the following segments. The same thing is happening between second and third segments. And I want to place 3 of this stages (9 subcoils in total) I will use 8mm caliber projectiles, 40mm or 50mm length. I chose 5200mkF 450V or 6800mkF 400V capacitors, 2 of them in parallel for every stage (6 capacitors in total) Yes, I know it sounds way too powerful, but that's my actual goal. It's not my own idea. I have learned it from here http://gauss2k.narod.ru/adf/gs3seg.htm (русские вперёд). So, some problems had appeared. I can't figure out how to properly calculate the required inductance of the coils. In the source it is said that the inductance of the first subcoil should be equal to two of the second and the third subcoils (L1=2*L2=2*L3) to achieve the best performance. Also, my rough estimates show that peak current through the coil will be about 1,5-2,0kA for 3,0-4,5ms. This is quite a lot! I'll have to manage this energy and choose the power switches rightly. To sum up, I will be glad to hear your opinions about this idea. It's kind of controversial, but I hope it's not a certain failure.

Topic by CosmoKnight    |  last reply