Homemade Definition and 138 Threads

I am an electrical engineering student. I have been on summer break for a few weeks now and I had time to work on my project. This is not a school project but something I had wanted to complete for a while. I haven’t decided what I am going to do with it yet. I just built it for the fun of it...

is it safe to wire like 4 turnigy 11volt 2200mah 25c lithium polymer batteries in series and 4 in parrell using dean connectors? The reason I am asking is becuase I see some battery packs online that are expensive for the power they output. If lithium polymer is unsafe is it safe to use smaller...

Homework Statement A homemade capacitor is assembled by placing two 9-in. pie pans 4 cm apart and connecting them to the opposite terminals of a 9-V battery. Estimate (c) the electric field halfway between the plates. Homework Equations V=E x d The Attempt at a Solution As it says "halfway" I...

After a wrist injury I had to stop lifting weights. This was annoying so I decided to make an arm brace that would transfer the weight of a dumbbell through my forearm rather than through my hand and wrist (with the help from my local metal works). I've now got the brace and its perfect, aside...

Hi all, My friend and I have created a homemade supercapacitor. It can power a LED light and small alarm clock. We charged it up to 1.5 Volts. I was wondering if anyone knew how to find the exact capacitance in Farads, any help will be appreciated. I have added the steps that we have taken in...

Hi, this is my diesel-electric conversion for what was a battery only powered platform truck. Its got a 30hp diesel engine, a 6 Kw DC generator, and another 6 Kw AC generator. One thing to point out is that I'm running it only with the generators, no batteries. Here's some pics of it: Diesel...

Homework Statement I'm doing a physics demo, and I've made basic electromagnet using some copper wire, a 6 volt battery, and a carbon steel screw, and I need help checking my calculations because I think the magnetic field for my magnet is too large. I've double checked everything and can't...

Audible hearing range for humans: Roughly 20-20khz That's almost 20,000 values to choose from:eek: Other/additional info: I don't understand your question BeautifulLight. If your circuit is operating at 2khz, then calculate for 2khz. Simple. Well, this is for a speaker. Human speech can make a...

what is Deposition, also known as desublimation, point of CO2 is it room temperature? i don't think so then how can we obtain this at room temperature as in this video and what pressure is required to solidify co2,is it 1 atm ?i don't think so then how we obtain this in a room as in above...

Hi guys! I am doing a project for my High School, here in Spain, that is obligatory for everyone. As a love everything related with planes and aerodynamics I've decided to create this wind tunnel. Is approximately 2,15 meters long and it weights around 10 kilos. It is made 100% of wood and it...

For the last six or so months I've recaptured my childhood love of rockets (I'm now in college), and have spent a great deal of time both reacquainting myself with the basic information and also learning more about the engineering and technical side of them (now that I've learned things like...

I'm trying to make an electric lighter ( like this http://imgur.com/a/wg8q7) using the framework of this guide. http://www.instructables.com/id/Make-a-battery-powered-soldering-iron/?ALLSTEPS except mine will have a few more feature and the soldering tip will be replaced with nichrome most...

I'm trying to make an electric lighter ( like this http://imgur.com/a/wg8q7) using the framework of this guide. http://www.instructables.com/id/Make-a-battery-powered-soldering-iron/?ALLSTEPS except mine will have a few more feature and the soldering tip will be replaced with nichrome most...

Hi everyone, Some time ago i made a DIY AC Stick Welder, while i understand the basics of the machine, heat disipation, AC Arc and etc dynamics, I've some doubt i would like to clear before i proced with some modifications. First ill attach its specs and diagram: It works on...

I am building a two coil DC motor as a project. I have two neodymium magnets, an aluminium split ring, and alligator clips acting as brushes, connected to a 9v battery. For some reason it is not working and I cannot figure out why. Can anyone think of something I may be doing wrong. I can post...

This experiment is based on a Scientific American article from April 14, 2007 ( http://www.arturekert.org/sandvox/quantum-eraser.pdf ) or ( http://www.angelfire.com/folk/thegrieves/transfer/200705.pdf in renderable text). The article demonstrates how to set up an experiment that illustrates...

I have built the following circuit which uses the comparators inside a 555 timer to control the charge of a 12 V battery from a solar panel. The circuit is adjusted (via pots R1 and R2) so that when the battery voltage gets under 12 V, the relay connects the solar panel to the battery so it...

Hi, Recently, I made a batch of smoke bombs using potassium nitrate, sugar, and baking soda (to regulate reaction speed). My first batch took about four days to dry which seemed odd, however, they produced a fair amount of smoke. For my second batch, I decided to put the potassium nitrate I...

This is a homemade generator I've been trying to make using a hand crank, neodymium magnets and two copper coils. It doesn't work. If anyone has any suggestions on how to configure the magnets or something I am doing wrong your comments will be much appreciated. Thanks!

im a student working trying to start a project creating a motion sensor and camera outside my door way, was wondering if anyone had any ideas of how i should get started. i don't want to buy the sensor because i want to learn how to produce the product from scratch, any help would be great

Hey guys, I built up this design for a hand-powered crank generator with four neodymium magnets, but am having trouble getting a reading through a voltmeter. I want to try and amplify the voltage as well but that will come later. Here is our setup http://imgur.com/a/0aM4W#0 I am not...

Hi, I've recently made some very budget homemade 'beer', butt I'm wondering is there an easy (doesn't have to be accurate) way to determining ethanol and methanol content. any help appreciated.

Hi PF, I've been looking to do a physics project for a while, and I thought about trying to build a particle accelerator at home. I know there's a lot of potential risks involved, and I imagine some legal issues, but is it plausible for a 15 year old to build a crude particle accelerator at...

A while ago I had asked if anyone ever made liquid nitrogen from scratch without using a prepackaged cooling device (cryocooler). Well, I've done it. I'm working on a web tutorial and better video footage. For those who wish to make suggestions on what you would like to see I am submitting...

Hi Everyone, I'm trying to make a homemade solenoid to lift a metal slug, and i have a 2000mah / 7.4 V / 20C lithium polymer battery. Is this battery going to be sufficient? Here is a photo of my current setup without the battery: side view top view Thanks in advance!

I want to make an elevator lift from an electric motor. The motor has a 42 mm shaft that turns at 1800 rpm. I want to lift approximately 200 pounds total twenty feet high, slowly and safely. I was hoping someone with knowledge of pulleys and gears could help me figure out what I need to...

Hi, First post, and this stuff is way above my head so i am hoping some one can help me. So what I am after, i am after building a solenoid to to open a valve, this valve is holding back around 3000psi compressed air. its from a pressure washer gun. and takes quiet abit of force to open...

Hi, As part of a larger hobby project, I'm building a microgram balance based on the one described at Sci-Toys.com, but I believe my questions are appropriate for the "general physics" forum. Background: I purchased a 36" threaded steel rod, connected it to a razor, and then put it on a...

Hey everyone just curious to how i would go finding the appropriate power needed to move a 20-25kg device around. I want it to be roughly walking pace so don't need a large motor or anything like that but could someone help as to find out approximately how much force, torque etc i would need to...

Hello, recently saw video demonstrating newly developed armor based on non Newtonian liquid. Such armor is being still researched but is very promising, flexible, lightweight and can stop even heavy stabs with sharp pricker, maybe even bullets. Liquid armor itself is based on two components -...

hi i am working on a project which is to build a pickup winder for my guitar from a printer motor. the printer (an old lexmark 3200) ,has 2 stepper motors(10ohms and 5 ohms),and i intend to use one of them for rotating the pickup on an axle and the other for controlling the lateral traverse...

Hey guys. I am new to engineering and I came to this because I wanted to make my own miniature jet engine. I have a limited knowledge of physics but I wish to broaden it through this idea. Now I know that this was made before for RC models, but I want to actually make one so I understand how...

[1] Good afternoon anyone! I am a Petroleum Engineering student at Palawan State University and conducting a research. I have seen a topic of research, and it is: The Production of Petrol from Air and Electricity, and I need to find some reaction equations for my topic, here are some: Air...

Hello, after failing on a few circuits I thought I need to be able to swap and change my components a little more easily then soldering all the time. So I've built a reusable solderless stripboard, that I can swap and change my components around. I had a bunch of 18pin DIL sockets that I got...

Hello, I am new to the forums and physics in general. I hope I am not posting in the wrong place. My understanding of physics in general is rudimentary at best, so please let me know if any of my statements are incorrect. I understand this is an extremely long post, so feel free to jump to...

First, I'm not looking for an exact number here or anything like that. More just bouncing ideas around and talking out loud. Say you have a mid 90s Ford Ranger with a manual transmission. You remove the original motor and get some type of small diesel engine (Kubota, VW, Mercedes, 4BT...

By rolled, I mean this kind of basic homemade capacitors: http://www.ehow.com/how-does_4852927_building-a-capacitor.html Kind sirs, I have few questions regarding this kind of capacitor: 1.) Would I still be able to get the 'theoretical free-space' capacitor of the same dimensions using C_o =...

First, I know nothing at all about this topic, which is why I'm looking for help. I'm interested in building a radio transmitter/receiver like a child locator at home. The difference would be I'd like the receiver to beep rather than the transmitter, if that's even the correct language to use...

I want to make a parallel plate capacitor without dielectric between it, that is, a capacitor with free space. Can I do a working capacitor with just a two parallel cardboard coated in aluminum? I figured it should look like this: Also, if there's anyone who's got a better idea on how I...

Particle accelerators are, to my understanding, a device capable of accelerating protons or electrons to very high speeds. At these speeds many things can be done to the particles. But most accelerators are very expensive and large. A smaller, cheaper accelerator would not be as effective as a...

***Note: I am not trying to make a laser that I can sell or profit from (well at least not now anyways :biggrin:); I'm just focusing on trying to make a laser that is crude and simple, but also one that I can be proud of; thanks.*** I have done a decent amount of research on lasers, and...

Hey guys, I'm new to this forum, and I want to start off by asking about some help to understand the composition of this circuit. The circuit is made by Kip Kedersha, and is found http://www.howcast.com/videos/1499-How-To-Make-a-Homemade-Lie-Detector. This is the circuit: I'd like to...

Hello! Long time reader, first time poster. First, I am sorry for my bad English, but I haven`t practiced from a very long time and this is not my native language. So, I am studing Physics. I and a classmate make DIY projects. We`ve made quite a big list of things - R/C models, tesla coils...

Hi guys. I'm building a dynomometer for a 1hp engine. I plan to use something like an alternator or a dc generator to do the braking. I will mount the alternator or generator so it is free to rotate around the shaft and measure the force at a distance to get the torque. The idea is to vary the...

So, I made a marshmallow launcher that has a small tube within a larger tube that when a bungee is released it gets launched into the larger tube, smacking the marshmallow and sending it flying. Woo! My problem is that I want to use the equations for projectile motion, I know the angles I'm...

1. Homework Statement A Homemade compound microscope has, as objective and eyepiece, thin lenses of focal lengths 1cm and 3cm, respectively. An object is situated at a distance of 1.20cm from the objective. If the virtual image produced by the eyepiece is 25cm from the eye, compute (a.) the...

Hi I am trying to find a motor that you could attach a chuck to and have somewhere around 2.5kgcm torque, with a speed variable between 60rpm and 180rpm, controllable with a foot pedal (smilar to a sewing machine pedal). Ideally there would be a clutch in there as well. Is there anything out...

Hi, I was thinking of making my own power supply and I was wondering how low level I can go with it in terms of designing individual components and then putting them together to form the circuit. So, I'm looking at like a 120V to 15V transformer then through a rectifier to get 15V DC? I'm...

Dear all, Just as the title says - is there a practical way to make homemade 3% hydrogen peroxide? I'm looking to move to a remote section of Texas where medical help may be hours away and I know how H2O2 can prevent serious infections and has other medical purposes. Any help is...

These "Homemade" Solar Panels...Do they even work? http://solarpanelhandyman.com/uncategorized/how-to-make-a-diy-solar-panel-simple-steps/" I am trying to figure out a project to make for a class of mine, where we have to build a "Green" type system, bla bla... Has anyone ever tried? Do...