Hey,    I have a robotic project that I have a deadline for. i have everything in place, but i cant think of how to connect the linear actuator up to my Vex Cortex Microcontroller. it has 5 wires, but I cant fit them in any of the outlets. Sincerely, I cant give my name out

Posted by therobotman 5 years ago

Linear Magnetic Field

I am stuck in my research,please tell me a way to make a linear electromagnetic field,other than making an outer core for it please help me

Posted by ajose4 4 years ago

Seeking someone to hire for a project

Hi, I'm not sure if it's appropriate to post this inquiry on instructables but I thought I'd give it a try. Basically, I need a dial that would command this linear actuator to advance in one inch increments on either a dial or a touchpad or a slider. I'm not an engineer and I don't really have time to build this myself - would anyone be interested in doing this for a fee? If it would help in assessing the project, I now this controller would work However, I need the dial or touch pad to allow for discrete steps and not be sort of vague. Any help would be much appreciated. I'm just not sure where else to turn. Thanks, Evan

Posted by EvanB65 1 year ago

linear strip photovoltaic panels

Hi, I was wondering if anyone knew where I could find strip PV (photo voltaic) panels. I have small pv panels 3in by 3in but i am looking for longer strip pv panels maybe an inch long by however thanks Jon

Posted by gwydionn 7 years ago

LIM Question

I have a question about linear induction motors. I can't seem to actually find the answer anywhere. Is one rail a permanent magnet and the other an electromagnet, or are both of them electromagnets?

Posted by puffyfluff 9 years ago

*linear* PWM LED fade with arduino

Arduino comes with a simple program to make an LED fade on  or off, however, as far as I can tell, the apparent brightness of the LED does not change linearly with the wpm duty cycle. After some research I found that this is because humans percieve brightness logarithmicly, not linearly. (Also, LEDs don't change brightness linearly with current, but sisnce I'm using PWM, i don't think that comes in to effect.) I found a simple look-up table to correct for this on this page. 255, 180, 128, 90, 64, 45, 32, 23, 16, 12, 8, 6, 4, 3, 2, 1,0 This seems to work very well, but I don't know where this comes from. Does anyong know the ectual equation to get the % duty cycle from the %brightness? I like to abstractise things.

Posted by Vick Jr 8 years ago

lift table from old adjustable bed

Have two old electric linear screw actuators that work great. I Need a lift table but can't figure out how to put it all together. I don't know what width or type of metal use for the lift or the bolt hinges???.  Does it have to be a scissor lift or can I keep the actuators where they are at each end of the bed, wire them to work together and make a lift that way?  I need an affordable way of doing this and it only needs to lift to about 500 lbs. from 17 inches off floor to 30 inches off floor.  All framing is angle iron but seems heavy duty. Anyone's help if greatly appreciated as I just cannot afford to spend $ 1000. + on an electric massage lift table. The pic is after everything but the motor/actuators were removed. Thanks Deb

Posted by DebMaudie 3 years ago

How to tilt a bed / linear actuators?

I'm thinking about making an alarm clock that literally gets me out of bed! The alarm clock would start tilting the bed to one side, untill i either get out of bed, or fall out of bed :) I was thinking of using linear actuators on one side of the bed to do the tilting. Does anyone here have any experience with linear actuators? How strong are they, and where can I buy them cheaply? Any other ideas on how to tilt a bed? Cheers - Chr

Posted by chr 10 years ago

X-Y stage for film scanner

I'm building a film scanner using a dlsr. Here's a picture of the rig so far: Basically there's a light source, negative stage, negative holder, camera support stage, camera and lens.  I put a negative in the negative holder and slide it using a guide such that I can take a bunch of pictures of the negative at 1:1.  For example, it takes 25 pictures to cover a 6x7cm negative.  The individual files are then combined into one file using stitching software.  The system works very well, but it's a bit tedious.  I'd like to automate the negative movement using a diy motorized xy stage.  Many of the designs I've seen are for much bigger units, such as for a cnc machine, or units that require speedy movement.  That's not the case here.  Each movement would be only 10-20mm. I'm fairly handy, and I can follow directions/recipes well, but I haven't worked with arduinos or stepper motors before.  Any advice or suggestions on a good way to accomplish my goal would be very welcome!

Posted by pdesmidt 6 years ago

Hack your Servo V1.00: Make a powerful linear actuator using a standard hobby Servo

Hack your Servo V1.00: Make a powerful linear actuator using a standard hobby Servo   Provided you have the tools and the servo you can built this for under a couple of bucks. The actuator extends with a rate of about 50mm/min. It is rather slow but very powerful. Watch my video at the end of the post where the small actuator lifts 10kg vertically.   Materials List Tools list   - hobby servo - standard hobby brass tubing             -OD: 4.0mm, ID: 3.4mm             -OD: 5.8mm, ID: 4.5mm - standard hobby styrene tubing                                                 -OD: 4.8mm, ID: 3.5mm - M4 studding - 2 x M5 washers - 2 x M4 nuts - 5 minute epoxy - cyanoacrylate - grease - multi-strand cables - heat-shrink tubing   - standard tools – screwdrivers, scalpel, files etc. - dremmel multi-tool with ceramic abrasive disk, or similar - hand-drill + 4.9mm + 2.5mm drill-bits - M3 tap - M4 tap - soldering iron - glue gun - small vice - small saw - sanding paper (relatively fine) - small flame torch Procedure - I will be giving instructions based on the dimensional parameters of the Hitec HS-300. The procedure remains the same for any type servo. I strongly recommend you read the whole post before you start. So lets make a start, shall we?   - Open your hobby servo, remove control electronics, feedback potentiometer and mechanical stop on the servo’s output gear.   - Solder new cables on the servo motor’s leads.   - Drill two 4.9mm holes on the servo case bottom cover. These should be located longitudinally along the centre line and 9.5 mm from each end (this applies on the Hitec HS-300 and is also true for many standard servos but depending on your servo type there might be differences). The M4 thread will come out from the servo body using one of these two so this hole must be located directly below the centre of rotation of the servo’s output gear. Be very careful since this alignment is very important! If you don’t get it right you might have to use a new servo! The more accurate you are, the longer your servo will endure. -  Measure the dimensions of the rotating shaft of the potentiometer on the servo’s original electronics – note the geometry in general. The shaft should be flattened right at the tip in order to prevent it from freely-rotating once inserted into the servo’s output gear.   - Take the M4 studding (M4 thread) pick one end and by using the dremmel and the abrasive wheel tool, replicate the tip of the servo’s potentiometer on that end. Start by decreasing the diameter of the thread, rotating it steadily by hand against the abrasive disk (normally to 3.5mm in diameter and at least 6mm in length). Try to think of your fingers as the chuck of a slow-turning lathe. Once the diameter of the thread is down to the pot’s shaft diameter, flatten the tip according to the potentiometer’s tip. The idea is that the thread must be inserted in the servo’s output gear in the same way the potentiometer did before. The better the fit the longer your servo will endure. - On the flat tip of the M4 thread, screw the two M4 nuts approximately 20mm down its length. Following that, insert the two M5 washers. - Insert the thread inside the servo and adjust the distance of the nuts and washers down the thread such that the servo case bottom cover closes properly and the motor rotates efficiently. Basically, you have to make sure that once the thread and the servo are assembled there is no pressure between the servo case bottom cover and the nut-washer assembly. Similarly, you have to make sure that once the thread and the servo are assembled there is no gap between the servo case bottom cover and the nut-washer assembly. Once again, the better the fit the more your linear actuator will endure.   - Once you find the optimum position carefully disassemble the servo, remove the washers from the thread and use a drop of cyanoacrylate on the side of the nut that was in contact with the washers in the assembly. Let the glue to settle for 5 minutes. Unscrew the second nut by 10mm towards the flat end of the thread, and prepare a small epoxy mix.   - Put the mix between the two nuts and screw the second nut back in place. Once in place also use some epoxy on the back of the second nut as well. Ideally you should sand all contacting areas before you apply the epoxy glue. Leave to settle for at least 6 hours (even if you use a 5 min epoxy). - Secure tightly the 4mm diameter brass tube onto a vice by flattening the mounting end and use the M4 tap VERY carefully tapping as deep as possible (at least 15mm). Using the dremmel cut 10mm out of the threaded part of the tube and then verify that the created thread runs along the whole length of the small threaded tube by screwing it onto an M4 screw. Keep the 4mm threaded tube on the screw for handling purposes. Apply a layer of solder on the outside surface. - Take the 5.8mm diameter brass tube pick one end and try to sand at least 5mm into the tube (on the inside). Mount the brass tubing on the vice without squishing it and apply a thin layer of solder on the inside.   - Ignite the flame torch, take the 4mm threaded tube (holding it by the screw) and move it on the soldered end of the 5.8mm diameter brass tube which should still be mounted on the vice. Using the flame torch heat-up both tubes and carefully insert the 4mm threaded tubing inside the 5.8mm tubing until is fully inside. Use a pair of pliers and insert the brass tube by holding the end of the screw that sticks out. Hold the threaded tube levelled inside the 5.8mm tube until the solder settles. If you do not have a flame torch use a candle, your soldering iron and your patience :). Remove the screw. The end result will be the cylinder of your linear actuator. - The cylinder length should be equal to: the actuator’s desired working length (stroke) + length of the 4mm threaded tube which is inside the 5.8mm tube + 10mm for the mounting hinge at the cylinder end.   - The thread length should be: the actuator’s desired working length (stroke) + length of threaded tube which is inside the 5.8mm tube + length of the thread which resides inside the servo casing, which is model-dependant.   - Take the non-threaded/non-soldered side of the cylinder and drill a 2.5mm hole through, 5mm from the tip. - Cover the entire length of the cylinder with heat-shrinking tube and cut-off any excess bits. The 2.5mm through holes made earlier on the non-threaded side of the cylinder are now covered. Use the drill again to expose them and tap them through, using the M3 tap. Screw a 20mm long M3 studding or simply cut-off the head of a 20mm long M3 screw. This will act as your cylinder mounting hinge.   - Take the 4.8mm styrene tubing and M4 tap it 10mm deep. Cut a small ring 5mm in length and screw it in the M4 thread fully, from the side of the nut that was in contact with the washers (long side of the M4 thread). This will act as bushing between the thread and the servo’s case bottom cover. Ideally you should use nylon, copper or metal bushing. - Secure the motor cables inside the servo casing using a glue-gun and use heat-shrinking tube to cover them. Assemble the servo including the thread, the styrene bushing and the washers.   - Screw-on the cylinder and you are good to go! Here is a video of the small actuator lifting 10kg For those of you that have watched my video on the MTR Rover     will understand where the idea of hacking the servo came from ;))   Soon we will be posting assembly instructions, code and schematics on how to modify a standard servo to get full PID speed and position control with 10-bit resolution over 360 degrees – continuous ;)     I look forward for your comments!    

Posted by Antonb 8 years ago



Posted by maeku 7 years ago

the use of threaded rods for cnc miller and cnc 3d printers

I got some threaded rods today. They look straight. 16 threads per inch.  The tag on one of the shorter ones says 3/8" - 16x36", course threads, zinc plated 1700lb. I was planning to use these for the x,y,z control for a 3d miller/printer. I realize it may be slow. Someone mentioned that the McWire repstrap uses a 4 1/20 (the only part I understand is 20 threads per inch) was really slow, but someone made it work with 2 1/16. I did not really have plans to attempt position verification because I think the resistance vs torque should be minimal for a threaded rod setup. I figure I could get away with just sending it specific pulses for a specific amount of time. Could I have some feedback on this?

Posted by nstenzel 6 years ago

Wanted: Controller for Linear Acuator

Basically, I need a dial that would command this linear actuator to advance in one inch increments on either a dial or a touchpad or a slider. or 917 414 5472 Thanks! Evan

Posted by EvanB65 1 year ago

wiring limit switches on a linear actuator

I am trying to wiring two limit switches onto a linear actuator. One to stop the extend stroke but will allow you to retract the actuator. The other limit switch will stop the retract stroke but allow you to extend the actuator. The actuator is installed on a door I need it to stop on the extend stroke and the retract stroke so it doesn't damage anything. I have an LACT8-500A actuator and the company doesn't make a limit kit for the adctuator.

Posted by youaintwrong 8 years ago

Looking for someone to help buld an Arduino linear measurement project.

I'm looking for someone to help me build an Arduino linear measurement project. I need to measure less than 6" stroke with some accurate repeatability. I'm willing to pay for the programming and any parts I might need. Email me if you are interested in working on this with any questions you have... Thanks, 

Posted by rpmlou 1 year ago

Antique Bicycle, Human Sonar, The Linear Clock

Antique Bicycle Human Sonar The Linear Clock Learn Business Card Throwing DIY Gorilla Pod Make Whimsical Furniture Kids Riding Crane Gourmet Chocolate Truffles Kill Bedbugs With Christmas Lights Instant Limoncello Cardboard Cryptex Vault $3 Xbox Kinect TV Mount Remove Vinyl Tiles With Dry Ice Challenging Bolt Puzzle Build a Printing Press

Posted by randofo 7 years ago

wiring a linear actuator with relays

  Hello everyone. I'm trying to run a linear actuator with built in limit switches by remote control. I bought the remote from a parts store. The remote was supposed to be used for windows up and down, door locks and other stuff. I would like to be able to use the relays that I already have on hand. I want to be able to push a button on the remote and the actuator go all the way out or in without holding the button down the whole time. Thank for your help.

Posted by papermaker007 7 years ago

Torque to linear thrust through lead screw

Hi,I am trying to figure out maximum linear force I can produce with an electric motor through use of lead screw and nut. I have come up with an equation which seems correct but resulting forces are way higher than my intuition believes is correct.I tackled the problem from the perspective of energies:F' * p = M/r * 2*π*rlinear force * thread pitch = torque / radius [M/r = force at radius] * circumference of lead screwF = 2*π*M/p * (1-k) //k stands for coefficient of friction between lead screw and nut)Radius falls out of equation, which seems fine as force is provided by torque, which is radius agnostic. I used a 7€ stepper for source of torque which can provide 0.42 Nm of torque and a lead screw with 8 mm pitch and 4 mm radius, I assumed 15% losses. My equation tells me that such system can provide 280 N of force, which seems wayyy too much for a cheap motor.I have attached a python code that calculates linear force in case it helpsCan someone tell me if my equation is either correct or flawed?

Posted by ptkrf 7 weeks ago

Buy Radios, Amps and Repeaters , Icom IC-PW1 Linear amplifier, HF+6m 1kW solid-state

Contact me if you are interested in any of the rigs listed. Amps and Repeaters , Icom IC-PW1 Linear amplifier, HF+6m 1kW solid-state Kenwood TS 2000 Kenwood TS 990s Elecraft K3 Elecraft KX-3 FlexRadio 5000a FlexRadio 6300 Icom IC 7800 Icom IC 756 Pro III Icom IC 7000 Acom 2000a Icom PW-1 Email Pictures and price available on request. (73)

Posted by BECKONX 2 years ago

stewart platform with firgelli linear actuator using arduino codeing help!

I am building a stewart platform as part of a larger assembly to accuratly position an object in all six degrees (transition in x,y,z) and rotation about each of these (pitch, yaw, roll). I plan to use an arduino board and 6 firgelli linear actuators. Any help on how to go about programming this would be a great help, or if anyone knows of any open source code so that I do not have to do the reverse kinematics as Im not strong enough in math to do so. ive attached a pic screenshot of my design. thanks

Posted by habbi_88 5 years ago

forked threads and linear threads

Hi. It's about how are organized threads into forums. Currently forum threads are forked : you can reply to a comment separately, and each of your reply will make a new fork if somebody reply to your new comment ... this makes threads like trees ... Personally, I don't find this system very handy, more particularly when the same thing is being actively discussed in several forks. This system is good for short chats and when commenting instructables, but when it's about debating, it quickly becomes confusing ... For the forums, I'd prefer a system with a linear thread where messages are ordered according to time, and where we have to quote the persons we want to reply to. Several discussion could get "multiplexed" on the same thread, but personally, I find that less confusing as long as there are quotes. What's your preference ?

Posted by chooseausername 11 years ago

RF Generators

Just wanted to know if Function Generators were the same as RF Generators? I'm looking for a cheap RF for a project and when I put in "RF Generator" in eBay, it comes up with Function, Signal, and Linear Generators as well. Thanks.

Posted by FrenchCrawler 11 years ago

How do you hook up a linear actuator to be controlled with PWM / R/C?

Hi Everybody, I'm working on a robotics project requiring strong linear actuators(LAs). For the most part I see that using LAs is the same as using DC motors. The red and black cables of the LA would connect to the motor +/- terminals of a motor controller. The main power source would connect to the battery +/- terminals of the motor controllers, and the motor controllers input could then come from a microcontroller or single board computer (SBC) using PWM / R/C control. This should allow me to control the direction and the speed of extension. However, for my application I and going to need multiple LAs the need to extend exactly in sync. The best way I can think to do that is to sense their individual extensions and program the LAs so that they stay in sync with each other. From what I've seen what I'm looking for are LAs with built-in limit switches and potentiometers.  What I don't know is how to hook these up to their motor controllers and microcontroller/SBC. An example I'm looking at is this one from Firgelli Automations:;_id=159. Unlike hobby servos this LA has 5 wires. Two are the positive and negative power wires and the other three relate to the potentiometer. I know you can control the extension this way but so far I've only found youtube videos and couldn't see how they hooked everything up. This datasheet for different LA ( helped me understand what the potentiometer wires do, but not how to use them with a PWM microcontroller. Does anybody have experience with this? Thanks for reading

Posted by honor_the_ways 6 years ago

Delta robot programming help

I recently created a delta robot with 3 rc servos and controlled with the arduino duemilanove. i was easilly able to create pre-programmed movements and get it to do simple repetitive tasks. but i would like to controll it with a joystic type controller(shown i pitcures) it has a 2 axis joystick and a single linear pot.i would like to use the joystick to control the x and y axis(foreward-backward,left-right) and use the linear pot to control up and down. the problem is is that the robot has all three axis on the same plane. so i need help trying to convert thes 3 seperate axis to controlling 3 planar axis. any help would be apreciated. thanks

Posted by budsiskos 9 years ago


I am wondering if you run a led at full voltage and amps then as you add more resistance light output goes down here is my question 1 led at 20ma or 2 led at 10ma do not 2 leds give more light than 1. Like is light output a linear taper to amount of current applied or is it more of an audio taper?

Posted by John1397 4 years ago

DIY Working Iron man

Here's an idea that someone can use for the robot contest if they want, I would but I just don't have the money.You buy 4 linear actuators (such as the ones here:;_id=7)And you attach one to each limb, giving you super strength.I just don't have like 500 dollars to spend

Posted by guyfrom7up 10 years ago

Request: How to wire a Firgelli L16P to an arduino

Hi, everybody. If you followed my instructables you know I'm always building robots.  I'm trying to assemble a Stewart platform using Firgelli L16P linear actuators.  My problem is that I can't seem to get the Arduino PWM to talk to the firgelli RC servo interface.  I have... - 12v running to controller pins 1 (-) and 2 (+) - arduino PWM pin 3 to controller pin 3 - controller pin 1 to arduino GND (for common ground) and I'm running a version of the servo sweep example sketch, modified to run on pin 3. The actuator doesn't move. I've tested the control board with the PC control software from Firgelli (works) and I've tested the arduino with a TowerPro SG5010 I had lying around (also works). Notice the controller LED will NOT come on in this configuration, but once I remove the common ground the light turns on. So what am I missing?

Posted by aggrav8d 7 years ago

Yoda Cake, Amphibious Couchbike, Bacon Soap

Yoda Cake Amphibious Couchbike Bacon Soap DIY Pixar Baby Lamp Zipper Earbuds Liquid-Cooled Car Seat Build a Marimba Homemade Rowing Shell Camera Ring Light Panning Security Cam Basic Linear Perspective Hand Crank Flashlight $2 Running Shoes Bright Bike Headlight Paper Towel Roll Flower

Posted by randofo 8 years ago

Bob Pease is dead

Bob Pease, the Analog design engineer who, while working for National Semiconductors,  developed devices like the LM317 regulator amongst many others, died yesterday in a car crash in Silicon Valley. Bob was a legendary figure to any engineer working in the analog domain. He died leaving the memorial service for another legend, Jim WIlliams of Linear technology, who died of a massive stroke last week. Bob was one of the nicest guys in the business, and mentored dozens of engineers in his long career.

Posted by steveastrouk 7 years ago

Hacking Flatbed Scanner Components

I am currently working on a project which was going to use a scanner to acquire an image. The scanner is/was an HP 6200C. When I was trying to modify the scanner I accidentally broke the lamp, but was then excited to discover [what I believe is] a linear photodiode array which functioned as the detector. (I also found some cool mirrors and a focusing lens inside.) This photodiode array could be very useful to my project.  This scanner interfaces with my computer through USB, and refused to work after I unplugged the lamp. I figure a resistor may trick the circuitry into thinking the lamp is still attached, but I no longer require the moving parts of the scanner at all; I only want the photodiode array and a way for it to interface with the computer, preferably giving either a "single line" type image or a "single really thick line" type image. (Basically I just need intensity and location of signal. If the received data is a full image, I can reduce it to what I need.) Does anyone have any experience or suggestions for me? I have uploaded a few pictures of the relevant circuitry and can add more upon request. Update: After further research, I've determined that it is not a photodiode array but a linear CCD.

Posted by rogers236 4 years ago

Digital Camera with ISO, shutter speed & aperture settings

Hi, i would like to make a very flat digital camera with the possibility to change the 3 principals settings : ISO, shutter speed and aperture. I would like to change those settings with a potentiometer so by rotation or with a sliding linear spot.   First question of i use a a mobile/iPhone camera  is it possible to adjust those 3 settings electronically ? If yes what do i need to make one ? Thank you. Thomas.

Posted by ThomasDsgn 2 years ago

What about a 3D simulation device??

Hi, Instructables community. This is a great place for making and sharing our projects. I am working on a 3D simulation device that uses rotational and linear motion wheels' axis as well as servos to control the finger position. What do you think about it? I had already made up a prototype. Can you suggest me if it would be a useful device? I think gaming. What are your views?? Thanks! :-) See you soon..... 

Posted by Gursimran Singh 425 2 years ago

Calculator Programs for Math

I've been working on some programs for my calculator recently and have decided to share them. I made these myself from scratch. If you want to modify go ahead just credit me. Don't sell them. And don't use them in math class if your teacher says not to. The programs are a follows: a quadratic formula solver, parabola solver, slope of a linear equation finder, and y-intercept finder. The programs work on TI-83's and TI-84's. If you have questions on how to use them or how to put them on your calculator please leave a comment!

Posted by sardines454 11 years ago

device that applies braking force proportional to speed?

Hi, I'm helping a team of students make a brake-assist device for a two-wheeled walker.  We were wondering if there are mechanical brakes out there that apply a force proportional to the speed.  A circular damper, is how we would describe it, I think.  Or something like a gas shock (the things on screen doors and car trunks) but with a circular motion rather than a linear stroke.  Anyone have any ideas?  Anything that's commercially available, small, and somewhat inexpensive is fair game.  Bonus points for things that can be made by hand..  Thanks!

Posted by _mattb 8 years ago

Dual energy generation with magnetic Seesaw system and gravity with the help of 3 volt toy motor

This technology is based on  a Seesaw system and magnetic repelling principle Linear motion  .We can generate electricity with very little force with the help of this technology.This will be a radical step in the field of energy generation. In this technology there will be a balance system and two heavy weight magnets(high strength NEODYMIUM MAGNETS) will be attached with each side of this balance system as per diagram. As per diagram there will be two moving weights and these moving weights will move on tracks.These tracks will be fixed at the angle of 8 to 10 degree. Two magnets will be attached on the front side of these moving weights and these magnets will have similar polarity with the magnets of balance system. These moving weights will be attached with two gear boxes and these gear boxes will be attached with two generators. HOW THIS TECH WILL WORK? When one side heavy weight magnet of balance system will be pressed with the help of any kind of external force then this side will come down and repel its side moving weight due to equal polarity of magnets.due to repelling the moving weight will move forward .but when the heavy weight magnet will move upward then this moving weight will move backward due to gravity to get its position back. in this way this moving weight will work to run a gear box and this gear box will work to start a generator to generate energy. This balance system will also work to pass through their side copper coil due to linear movement and in this way this technology will generate Dual energy. WE will take very high strength NEODYMIUM magnets  for balance system. I would like to insist on some following points (1) The balance system will be attached with 'L' form crank with external PRESSING source. (2) The moving weights will also be attached with 'L' form crank with gear boxes. (3) Each side magnet of balance system will work one by one .When one side magnet will come down the another side magnet will move up .These magnets will come down and move up one by one to repel their side moving weight. (4) We can take as much weight as we can of these magnets of balance system .(500 kilogram to 1000 Kilogram or more) to pass through the heavy coils having 100000 turns or more.  (5) External source of pressing this balance system could be anything such as pressing with foot  or solar cell. WE WILL NEED ONLY 3 VOLT EXTERNAL ENERGY TO PRESS THIS BALANCE SYSTEM  AND GENERATE MORE AND MORE ENERGY.

Posted by vikram_gupta11 2 years ago

Arduino and proper proximity sensor

Hi guys. I want to use a proximity sensor and an arduino to know when a person is in the shower. What I have in mind if that if the sensor measures a range of distance it would mean that the person is in the shower. I have made some research and the infrared Sharp GP2Y0A21YK0F seems appropriate for the distance range I need that is around 20-60 cm depending on the size of the shower. However I am ignorant in this topic and I want to know if the water from the shower will make an interference when measuring the distance and generally speaking if this is a suitable sensor for my objective. additionally I read that the voltage output from this type of sensor is not linear, would it be difficult to actually know the distance? Many thanks in advance :)

Posted by mcamiea 2 years ago

Using a Push Solenoid as a finger press to start video game console...Help please

Ok guys so Basically I have a plastation 2 console in my arcade machine, I want to be able to turn it on via a arcade pushbutton on the outside of my machine. The idea I have is to use a linear push solenoid to act as a finger to press the power button on the front of the ps2 everytime i press that pushbutton........ Is this possible? what type of push solenoid do I 12v? size etc.... and can I use a momentary contact pushbutton to power on the solenoid momentarily to do a single press of the playstation 2 power button? Thanks for any help... P.S. I have very little knowledge of robotics or servos and solenoid usage....but I can solder, wire, etc....

Posted by Negativecreep0 8 years ago

Building a full auto coilgun

I've been working on this project for about a year now, the first stages of the design started like 5 or 6 years ago. It is a full auto 19 stage no-capacitor coilgun. The accelerator is 3ft long! It will use an advanced coil timing system that should allow more efficient acceleration. The custom 3d printed magazines will hold about 90 shots, maybe a little more. It should be capable of firing at a rate of several thousand rpm but I might tune it down to ~500 rpm to keep it cooler running and make the ammo last. If you want to read more about this design you can see the page on my website:!em-guns/cwjy Here is a video showing the current progress on the coilgun:

Posted by Jaycub 4 years ago

Solenoid secrets?

Folks, I recently purchased some inexpensive 110Volts AC solenoid coils from China through eBay (of course.)  As I understand solenoids will convert electricity into linear motion.  I have been unable to do that.  I tried ferrous rods as plungers, they get stuck inside the walls of the coil's cylinder.  No ferrous material like aluminum rod did not work at all.  Can someone please guide me to make it work.  I purchased 110 Volt coil thinking that it will create a stronger field, I don't feel the strengths of magnets to be rather weak. 1. The coil gets hot when energized.  Will it burn out if I keep the solenoid energized for 4-5 minutes? 2. Should I go for a lower voltage DC coil? 3. What happens to the dc coil if energized for long time? I would greatly appreciate your comments. Thanks.

Posted by kabira 6 years ago

Light controlled wildlife feeder

I want to create a box where the lid opens up based on ambient light. Basically the lid closes at night and is open during the day. It will be a wildlife feeder that deters (nocturnal) raccoons from eating all of the feed but allows daytime wildlife to feast heartily. Is arduino the correct setup. My basic design is to have a linear actuator opening the lid but was also considering a crank type system (similar to a steam engine drive wheel). I need to either be able to control how long the actuator extends when enough light is present and reverse the action when not enough light is present or turn a servo motor with a crank a certain distance. Id prefer to use the actuator since the lid will be about 10Lbs and will need to extend about 10”. Is this possible? if so, how hard would it be for a newbe be to program? Thanks in advance for the advice!!! Ive attached a crude drawing.

Posted by tincupchalice 4 years ago

HELP! Electronic sequencer for vintage door chime.

Seeking any manner of help in making an electronic sequencer for a multi-note doorbell. I restore old door chimes and one particular model from the 1940's-1950's has an electromechanical linear distributor that works as the chime sequencer. It has a limited life expectancy- long since expired- and it defies repair. You can see details of this device by looking up patent number 2245443. The task to be done though is just like that of any more common chime sequencer that uses a rotary distributor. The idea is to replace the electromechanical mess with modern electronics to time the power sequence to three or four 16v or 24v solenoids. Looking for any help… guidance, advice, moral support... but mostly hoping to find someone who can design and build a few of these, as I am largely clueless about electronic design.

Posted by knock 11 years ago

Help me find a part!

Hello everyone. Looking for some help on this one. I can't find a clear defined picture of what is operating this sliding mirror. The dealers that carry it don't stock the mirror so can't tell me either unless I buy one, 3k isn't in my budget. I was thinking Linear Motion system but thats a high cost. From the picture I can see the stainless steel-track is L shaped. You can also see the mirror is set away some from the main cabinet, and also that the mirror is at the same height as the cabinet base. I've looked for casters, slides and other things I could hack but nothing seems to fit. You should not be able to see the hardware and thats a feature I would like to keep. I'd love your ideas or links to information. Thanks in advice. You can zoom well on this site.

Posted by edwinston14 9 years ago

Hiding ceiling projector

UPDATE! made some progress and have it all set up, its in the finishing touches area now. :) Items used- -12 in AC linear actuator -3 way switch - 4x draw slides - MDF - PVC - ceiling tile - various sizes of wood for frame for the actuator. ______________________________________________________________________________________ I have an idea for my ceiling mounted projector to hide in the ceiling tile and then lower down when a button is pressed. however I have no idea how to execute it. in theory I would need a motor to pull up and lower down the tile that the projector is mounted to and then run the cables down the wall to a switch. but I turn to you instructables to tell me how to make the motor stop when the tile is low enough on the cable and when it rises back into place with the other tiles. Sort of like an automatic window on a car. with the push of a button it goes into place and when the button is pushed again it rises back.?

Posted by cooy 7 years ago

Managing high-voltage lithium-ion batteries in HEVs

From EDN (Electronic Design News), comes this article: Skyrocketing energy prices and the growing concern over carbon emissions have focused attention on electric and hybrid-electric vehicles. New lithium-battery designs will be key technologies for efficient EVs and HEVs.By Michael Kultgen, Linear Technology Corp -- EDN, 4/9/2009Safely getting the most energy and lifetime from a lithium cell requires some sophisticated electronics. One requirement, for example, is the ability to measure the voltage across every 3.7V battery cell in a stack of 100 series-connected cells. How do you cope with the 370V of common-mode voltage and reject 100V of common-mode switching transients? The design of battery-management systems for EV (electric-vehicle), HEV (hybrid-electric-vehicle), and UPS (uninterruptible-power-supply) applications requires solving many such problems.How do batteries make cars "green," ...;=8848980

Posted by Goodhart 9 years ago

need help identifying component

I've got an old kenwood turntable, and it's having problems. Its a linear drive arm style turntable, meaning the needle/stylus arm travels in a straight line instead of an arc. The motor that drives this arm back and forth has a smallish flywheel type attachment (it looks like a fan blade, kinda). This little flywheel/fanblade turns through a very small gate that looks like a miniature stonehenge. I think this part is faulty, because the motor spins just fine (albiet with no control) with the part removed.  So it looks like some kind of photo sensor, and I need a new one. The part is about 3/8 of inch tall, with two bits on each side about 1/8" wide, with an 1/8" gap between.  Unfortunately, my digital camera is broken, so I can't take a picture of it. IF anyone knows what i'm talking about, some advice about where to find a replacement and what the part is called, I would be very, very happy.   

Posted by marcward86 9 years ago

Looking for more info on dish actuator

I received a free actuator from my friends cottage. 11 years ago it use to angle a 8ft dish. It was removed some time ago, and the label is fully off. The bottom says its a saginaw performance pak actuator, aka PPA, and it has a 24" arm. I was trying to find more information on it, and all I can find is that it can be heavy, regular, or light, 600-1,500 pounds dynamic linear. Anyone have one or any ideas? I cant find a model number on the case cuz it faded, but the motor says 7821645 or 1821645. Either way I found a tiny chart listing models but not that one. similar to that one there. I just want to find out how much force it has. Most I done so far to test it works aftter 11 years of rusting on the main shaft (the moving piston is fine) is sit on a box. It manage to push me with no change in motor sound. Any more details? Please ask!

Posted by Killa-X 9 years ago

DIY 4-component Buck converter, no ICs, need help with maths

I'm building a bike light around a Seoul P4 LED and some re-purposed 18650 li-ion cells from a laptop battery. I'll need 700mA constant current and can comfortably fit 8 cells in my enclosure. I've done some reading and I should be able to build a Buck converter relatively easily, but I'm struggling to find any good guides to help me spec the components. I asked on Dave Jones's EEVBlog forums and all the replies recommended either Linear Regulators (wasteful) or something designed using Webbench, which only helps with circuits featuring ICs. As a buck should in theory only need a transistor, a diode, an incuctor and a capacitor I want to build it myself out of through-hole components. Can anyone help with some guides or tutorials on specifying these components please? My degree was Computer Science and I was definitely better at set theory and boolean algebra than anything involving formulae!

Posted by ederfel 6 years ago

Integrating Highschool Sciences

Irene Duke, Kate Hoff, Lyndsay Carlisle and myself are participating in the MIT course 11.124, _Introduction to Teaching and Learning Science and Mathematics_. We have a variety of teaching interests: Irene hopes to teach chemistry, Kate to teach Physics, myself Physics or Mathematics and Lyndsay hopes to teach social justice / political history. Provided Make magazines as inspiration, we were tasked to design a joint activity, merging four high school classes of these topics for a period of weeks or months. We developed the ideas described in this first entry over the course of a class period. Hopefully, we'll take the time to expand each step into an instructable, possibly including trials by fire teaching 8th-11th graders. The material is structured by conservation of energy and resources, inspired by the articles of Tim Andersen. The final demonstration we envision motivates the particular material we wanted from each field. A bicycle wheel is drives an alternator transforming mechanical energy into electrical. The electrical energy is used to run a electrolysis process, rendering separate measurable quantities of Hydrogen and Oxygen. The Hydrogen and Oxygen are then combusted for the students. The amount of mechanical energy can be measured, as can the electrical. The binding energy of H_2O can be used to determine the chemical potential energy rendered. Finally, the combustion both demonstrates the energy's new form, and the difficulties in storing energy. The difference between power and energy underlies all of these experiments. Conservation of linear momentumn should be a familiar topic with the students. Conservation of angular momentumn can easily be introduced at this point, demonstrated with the bicycle and a fly wheel. Chaning the orientation of the wheel can be exteremely difficult. For the chemical portion of the experiment, stoicheometry should be familiar to establish the link between the amount of gas generated and the energy invested. The most appropriate mathemetical tools are statistical. Sampling, linear regression and averaging would prove useful throughout the experiments. Global economic relationships leading up from the colonial period would perhaps be the most applicable topic form history or the social sciences. Though not a technical detail, an important aspect of executing such an idea involves the actual deployment of resources. Students could, for example be broken up by their topic of interest, whether it be the physical, chemical or social aspects of the project. Next, new groups would be formed with one or two members from each subject area. These groups could then attempt to execute the design from the first slide, or one which is similar. Throughout, the students will present their thoughts or understanding to the teacher. This design project should perhaps be phrased as simply turning mechanical energy into hydrogen. Students with social scientific background might be responsible for estimating the costs of the implementation in different settings, and that would be used to drive a larger scale version. So, before getting started on building and documenting this project, do people have suggestions? What worked to combine the physical sciences for you? What might have worked?

Posted by mmt 12 years ago

What fittings can I connect together (building an air compressor) ?

Hi, I'm building an air compressor out of fridge compressors, propane tanks and NPT fittings from ebay, everything was cool until I received a check valve I ordered before all the other stuff (because it was from another seller so no need for a group order :) for one item). So I ordered a 1/8 female/female check valve (one way valve), and I measured the diameter with calipers, and it's not 1/8" (3.2mm) but a lot more, which makes sense, 3mm would be really tiny so now I don't understand how all of that works here are the fittings that will compose the system (those are 1/2 I guess but I will order 1/4 and 1/8 as well to make the complete circuit (around 20 fittings total): here is the check valve I already ordered (1/8 BSPP): I also noticed the valve is linear while the fittings appear to be the shape of a cone, will it matter ? Thanks in advance for any help ;)

Posted by nazmo76 2 years ago

36Vd.c. @ 8.3A Power Supply + Buck Converter

Hello Friends, I have a 36Vd.c. @ 8.3A Power Supply that I would like to convert into a Variable Bench Power Supply. After researching the topic, I have decided on choosing a Buck Converter as opposed to a Linear Regulator.  Shopping around online, I stumbled upon the LM2596 Converter:;=item462bb7a8a5                      Any thoughts and or suggestions? Beyond that, I do have a general question... I've read on a few power supply instructables that it's recommended that all rails be used (for example all yellow/12v cables) to insure a more steady current. Now being that the max output of the above mentioned power supply is 8.3A and (please correct me if I'm wrong) according to the supplied spec sheets, power is coming from 3 rails, would it be safe to assume it not necessary to feed all rails into a buck converter since its output is only 2A? Please put me in my place...

Posted by davidkiyan 3 years ago