### Bearing/fulcrum for a pendulum

I want to swing a locket on a chain like a pendulum and I want to minmise the friction experienced where the chain attaches to the supporting post. What sort of bearing or similar device should I use for this? Ideally it should be available in a bronze/dirty brass colour but I guess I can deal with it if it isn't.

Topic by THX 1138   |  last reply

### Synchronization of Coupled Pendulums

Check This OutI've been working on a related problem for one of my classes (Finding the natural frequencies of spring coupled pendulums with 2DoF). I just finished, and I did a quick Google search on coupled pendulum motion. I came across that link, which, I think, is very interesting.I just thought someone else might find it interesting :)

Topic by trebuchet03

### I want to build the Swinging Sticks.

I would like to build the swinging sticks (more famously seen in Iron Man 2.)   It is 279 bucks so I need a cheaper solution. Thanks for the help.

### Looking for a double pendulum and/or material to make one?

Where do I get the material to make a chaotic double pendulum. In fact I have a very tight time schedule - need this for delivering a lecture - so was wondering if someone has a double pendulum that they can provide (I tried chaoticpendulum.com but its all sold out). Thanks.?

Question by atulya   |  last reply

### Cheap calculator hack

I put together a Solarbiotics Magbot Pendulum and it has a period of one second. I measured this by using a stopwatch and counting the swings for five minutes. . What I would like to do is count the number of times it swings back and forth over an extended period of time, for example 24 hours.   I came across an article showing how to use a cheap calculator to count the number of turns a shaft makes. A cam attached to the shaft presses the "+" key each time the shaft turns one full turn. to use it, you clear the calculator and press the "1" button. Then every turn the cam presses the "+" button and 1 is added to the sum being displayed. Every cycle of the pendulum causes the LED to flash (pulse)  once. I'd like to use these pulses to do the electronic equivalent of pressing the "+" button.  It might be possible to count these pulses using electronic circuitry (decade counters) but electronic calculators only cost about a dollar of two and I'd like to give that a try. Any suggestions would be appreciated.

Topic by dickb24   |  last reply

### Cheap calculator hacking

I put together a Solarbiotics Magbot Pendulum and it has a period of one second. I measured this by using a stopwatch and counting the swings for five minutes. . What I would like to do is count the number of times it swings back and forth over an extended period of time, for example 24 hours.   I came across an article showing how to use a cheap calculator to count the number of turns a shaft makes. A cam attached to the shaft presses the "+" key each time the shaft turns one full turn. to use it, you clear the calculator and press the "1" button. Then every turn the cam presses the "+" button and 1 is added to the sum being displayed. Every cycle of the pendulum causes the LED to flash (pulse)  once. I'd like to use these pulses to do the electronic equivalent of pressing the "+" button.  It might be possible to count these pulses using electronic circuitry (decade counters) but electronic calculators only cost about a dollar of two and I'd like to give that a try. Any suggestions would be appreciated.

Topic by koyescha   |  last reply

### Pendulum length to falling body height ratio? Answered

How long does a pendulum need to be for its time period to be equal to the time it takes for a falling body to drop from a distance equal to the pendulum's length? A general equation as well as a specific solution for Earth surface gravity would be appreciated. With this, I would be able to establish standard time and distance units even if trapped on an island without any instruments other than what I can make from available materials. I'm sure I'm the only one tired that happening so often. Of course, I'd still need a way to establish the gravitatoinal constant if stranded on another planet...

Question by MDude   |  last reply

### What is the best Electronic/Electro Song? Answered

I like stuff like Leftfeild, Postal Service, Chemical Brothers, Prodigy, Pendulum, anyone know any other great tracks/bands?

Question by =SMART=   |  last reply

### An RTTTL for Pendulum - The Island Part 2? Answered

I also would like to find a good website where I can get RTTTL files, because I have had a few requests for stylophone tabs. Thanks, Flannel UK

Question by NatNoBrains   |  last reply

### An Exploratory Research Mechanism

Designed and Built by Emile Cole Range of Motion Video (profile).... http://www.youtube.com/watch?v=P_vF3...layer_embedded Range of Motion Video (front).... http://www.youtube.com/watch?feature...&v;=E7CEwnOFnCk   Hello all.... I've been working on this (hobby status) on and off over the last fifteen years or so.... a mechanism that immediately begins to rotate in either direction with an imbalancing displacement of as little as one degree. With repeated periodic displacements of as little as five to seven degrees its rate of rotation rapidly approaches about a 100 to a 150 rotations per minute over the course of just eight to ten repetitions, all while overcoming only negligible frictional resistance from the main axel (equipped with bearings). It may have some applications for extracting rotational motion more efficiently from wind and wave and maybe a couple of other things too.... or it may just be a work of art.

Topic by EmileCole   |  last reply

### How do I troubleshoot an old 8-day pendulum mantle clock, pendulum stops after 5 min., even fully wound, Any advice ? Answered

I have an old Plymouth 8-day mantle clock, chimes the hour and half-hour, probably from the 1920s. The gears/ springs/ escapement are mint inside, no bent, rusty, or corroded parts. I scoured local antique shops for a winding key, which I found for it. The clock ran well for one week straight until it stopped. Since then, I can't get the pendulum to run more than about 5 minutes! I leveled the clock, tilting it slightly forward or back, to no avail. I oiled the heck out of it, and wound the springs fully. It is a really cool old clock for my leatherworking studio,  no batteries or electric needed, and want to restore it somewhat original condition.  Any advice on this?  Thank you for your help.

Question by RetroLeatherHatter   |  last reply

### High school senior project: something I can construct and donate to the physics department any suggestions?

I want to build a demonstration unit that would be useful for the physics teachers.  It has to be fairly challenging to construct, but not impossible or particularly costly.

Question by danielsb7676   |  last reply

### What is this?

We spent a week at a beach house.  In the photo, you see a device attached to a door. There were several of them attached to doors throughout the house. It's a hollow steel ball attached to an arm, which was attached to the door. It could move back and forth like a pendulum, but it rubs against the door and doesn't move freely. You can see the rub marks on the door. So it didn't swing by simply opening or closing the door. This photo was taken in 2003 and I still don't know what it is or what purpose it served. If you know what it is, please leave a comment.

Question by hlanelee   |  last reply

### Gmjhowe - 5 | Fungus Amungus - 5

The showdown of the century!A deal has been made between the titans of teach! The sultans of social networking! The thrilla in Mozilla!Starting today, Monday September 29, 2008, Gmjhowe and Fungus Amungus have set a deal; Five instructables, in Five days. The Standings:Gmjhowe - 5:Leather Book BindingAdjustable Vesa Arm Laptop StandFriendly Papercraft FriendsThe Egg of TimeLeather Covered Pendulum ClockFungus Amungus - 5:Iced CoffeeInverted BookshelfMirror Ball ClockGinger Molasses CookiesGhost Shoes

Topic by bumpus   |  last reply

### electronics

I am currently working on a project that requires energy harvesting ,so i decided to use electromagnetic induction for the purpose. However I can not decided how to design my magnet and coil combination. All i know is i want 2.6-3.3v and 26mA for round about 4 ns. The setup in brief required a movable permanent magnet and a stationary coil. The moment of the permanent magnetic is like a oscillating pendulum just for once but with a sleed of say about 15km per hours. So can you please suggest me how should i start designing. thank you

Topic by SiddhantS6   |  last reply

### creating movement- pulsed coil magnet? other ideas? and how to accomplish?

I'm wanting to swing a small pendulum around (randomly would be nice).  I'm figuring something like is inside this candle would be the best method: https://www.youtube.com/watch?v=XM1c9Ny3X8E However, I don't know where to buy or how to make this (I can make a wire coil, but not program a chip to turn power to it on and off).  The candles are too expensive to buy to take apart.  Does anywhere happen to sell just that piece?  It would be great if I could just buy it, hook it to my 3v power, and I'm all done. Or does anyone have other ideas? Thanks.

Topic by aliasjanedoe   |  last reply

### Computer program learns physics

From Wired:"In just over a day, a powerful computer program accomplished a feat that took physicists centuries to complete: extrapolating the laws of motion from a pendulum's swings.Developed by Cornell researchers, the program deduced the natural laws without a shred of knowledge about physics or geometry. ...Condensing rules from raw data has long been considered the province of human intuition, not machine intelligence. It could foreshadow an age in which scientists and programs work as equals to decipher datasets too complex for human analysis."LinkThe software has a long way to come, but apparently it's showing a lot of promise.What do you guys think? If computers can do physics better than humans, does that make human physicists obsolete?

Topic by drinkmorecoffee   |  last reply

### 28BYJ-48 stepper motor driver....ULN2003 or L298N?

Hi, My goal is to have the 28BYJ-48 stepper motor turn clockwise and then counterclockwise periodically, like a pendulum motion. I have built a circuit using ULN2003 Darlington Array since most tutorials online use that. But recently I've seen some sources using the L298N Dual H-Bridge. Questions: Is it more efficient to use to L298N? I heard the ULN2003 draws more current than it needs. To add to the confusion, although the 28BYJ-48 is an unipolar motor, it can be ran in bipolar mode as well. Is the L298N only for bipolar mode? Here is the date sheet of L298N Does running a motor in bipolar mode offer twice the electrical efficiency than unipolar mode? In another word, if the load is the same, battery is twice as long (theoretically)? Please advise. Thanks

Question by DELETED_MakiY2   |  last reply

### Wanted: Instructable for Indoor Solar Chimes

I love the ingenious people on this site and am hoping some one can help me with this.  I have desperately tried to find an indoor solar chime like the one in the photo, but the manufacturer is out of business and other imitations are simply poorly made - unsteady curled metal base, only three wimpy cheap chimes, and mostly plastic. Can any creative, engineering minded soul help me out by writing an instructable for a similarly sturdy, aesthetically pleasing, (ceramic perhaps), resonating-5-toned solar chime like the one in the photo? The premise seems pretty basic - sun hits small solar panel creating vibrations which swing pendulum like mechanism which hits chimes and creates a gentle pleasing sound. I just have I would be very grateful if someone, more knowledgeable than me, would take on the challenge or at least shoot me some ideas on how this can be created!!  TIA

Topic by smiletime

### Barbie Electric Chair, Chaos Machine, Build a Pizza Oven...

Function clickclear(thisfield, defaulttext) {if (thisfield.value == defaulttext) {thisfield.value = "";}}Sign-up for our newsletter subscribe Sept. 6, 2007 Welcome back! We're seeing a few of the robots coming in from the iRobot Challenge this week as well as a variety of other cool projects. Check them out! How to Weld - MIG Welding A basic guide to the awesome process of using electricity to melt and join pieces of metal together.posted by noahw on Sep 5, 2007 PosterBot: Make a Marker-Writing Robot I always got marked down for posters that weren't "neat" enough. Like any nerd, I figured "If I can't do it, I'll make a robot to do it for me."posted by W_world on Sep 5, 2007 How to make Gingerbread Pumpkin Whoopie Pies Make a treat kids love in under 20 minutes.posted by DMR301 on Sep 5, 2007 Put an iPod Nike+ sensor in any running shoe in one minute for 5 cents Avoid buying specialized Nike+ shoes with this simple hack.posted by fungus amungus on Sep 4, 2007 How to build a Pizza Oven Create a functional piece of art for your backyard and start cooking.posted by t.rohner on Sep 2, 2007 Share your tasty recipe with us! Answer our burning questions! Get a free shirt! Make it fly! Barbie Doll Electric Chair Science Fair Project! This is a science fair project that I did in middle school and completely disgusted the entire female staff of Benton Middle.posted by jessyratfink on Sep 2, 2007 The Chaos Machine (Double Pendulum) Every physics department needs a double pendulum, so here's how to build one. posted by Luke Luck on Aug 31, 2007 Baby Space Invader Hat Let your little one go retro with this gaming-inspired knitting pattern.posted by tracy_the_astonishing on Sep 5, 2007 Golf Ball Gun!!! How To Make One That Can Shoot 400+ yards! Learn about pistons and pneumatics while firing golf balls through plywood.posted by MrCrowley on Sep 2, 2007 ServerBot - for serving food and drinks Create a robot that's helpful, entertaining, whimsical AND simply amazing. posted by JoeCreate on Aug 31, 2007 Now go build something awesome, and I'll see you next week! -Eric )))

Topic by lebowski

### Wireless Electricity!

I'm playing around with the idea of wireless power. It should be easily do-able over a short distance- my plan is to be able to charge something like my cellphone through induction, by placing it on a powered surface.. But- I don't know a whole lot about induction, so I was hoping someone could help me out a bit. Here is my setup: I'm using coils from old 5 1/2" floppy drives. I used them once before in a BEAM bot pendulum.. I set one coil on top of another. So far, by pulsing 9v DC through the coil, It sparks a little (because its shorting I assume) and the multimeter in the adjacent coil gives me a small spike of voltage, but quickly returns to zero. Zapping repeatedly gives me at best 2.5v, which is totally acceptable, if only it was sustainable. I've tried using AC 9v.. but I didn't seem to work either. I also tried some different on/off cycles with a BS2.. no luck. Any info would be quite appreciated..

Topic by sam   |  last reply

### Help me create wear-able eyes that can move back and forth for Halloween!

Hi!  This is my first time on this site,so i'm not sure where to ask for help with this.  I'm not very mechanically inclined, so I need all the help I can get to make this year's Halloween costume.  What i'm aiming to be is:  a Kit Kat Clock.  The tail wagging,eye moving pop culture kitchen icon.  I'm not so much worried about the tail bit, but the EYES are what are most important. I had this grand vision of using a headband and affixing some spherical shapes with some sort of battery powered way to make them move back and forth.  The goal is to wear them on my head, no matter.   Maybe altering a pair of sunglasses could be cool, but something tells me i'll have trouble seeing. Anyone, ANYONE with advice, please respond.  I don't even know where to start with this.  What are some things I can buy and take apart that would give me a back/forth - right/left mechanism?  The only thing that comes to mind is like a musical pendulum or something.  I would even offer money if someone has the know how to create this for me. Thanks!!

Question by valalltogether   |  last reply

### How do you make an escapement with a balance spring?

I have a problem My cat has a weak stomache so he needs to have a lot of small meals during the day, but there's not always somebody at home, so I wanted to make a cat feeder device for this. I want to make a disc that rotates slowly, during the day, leaving open another segment of a cilinder after every period of time. In every segment of the cilinder is cat food(which is poured into it that morning) Under the cilinder I want a clock mechanism, with a balance spring. I want to make it with a balance spring because it shouldn't be too high, my cat needs to be able to reach it's food normally. I've made a mechanism with a pendulum before, but it was one meter in height, while now i want the mechanism about one inch in height. I thought only a balance spring would fit right in the cilinder under the feeder, but I never worked with one, I don't have one either. How does a clock escapement with a balance spring work? And how can I get a balance spring? Can I just roll a long metal strip intro a spring? My cat feeder doesn't need a complicated gear train, because whether it makes one revolution in 10 hours, or in 14 hours, that doesn't matter. thanks

Topic by merijnvw   |  last reply

### iPods as scientific tools (app-creation challenge)

I can't help noticing that there are a lot of kids with iPods at my new school. I have a half-warmed idea that this is an under-exploited resource - these things are packed with sensors that most schools cannot afford to buy for themselves. Does anybody know of any apps that can be used to easily access this data in a form useful for students?  For instance: the iPod replaces the bob in a pendulum and records the time it takes to swing, and the forces acting at each moment of the swing, then displays the data in a graph on the iPod, or uses the wifi link to email the document in a form that can be used by an Excel spreadsheet. And not just acceleration and time, but sound and light (isn't there an ambient brightness detector in there somewhere?). Suggestions? Any recommendations? Edit Kitewife bought me an iPod Touch for Christmas!  I have so far installed the following apps that use the on-board sensors; SPARKvue (accelerometer display), Signal Gen (an audible signal generator), SoundLevel (a free decibel meter / sound oscilloscope) FreqCounter (displays a continuous full-screen oscilloscope display Decibel 10 (analogue & digital sound level meter, which will email data for you) SpiritLevel & iTools (for measuring angles and levels by moving the iPod) Protractor (lays a protractor over the view through the camera, allowing you to measure "real" angles you can't reach (say, of a roof-line, or between branches of a tree). What I cannot find (yet) is a decent app that gives a class-room-useful read-out of light levels - they don't tell you the light-level, they tell you what f-stop to use on your camera. The next job is to find ways to use them in lessons, or as homework tasks. Question: Is anybody reading this able to actually create their own iPod Touch apps?  The apps I've downloaded so far are fine, as far as they go, but they really need a better way of getting the data out in a form that can be manipulated (eg by spreadsheets).

Topic by Kiteman   |  last reply