Upcycled Technology

by Daniel Davis

  Step 2: Installing the Webcam as a Backup Camera

  The next trick is getting the webcam to stick to the back of the car while keeping it connected to the smartphone that will be at the front of the car. As for getting it to stick to the back of the car, I hot-glued a couple of strong rare-earth magnets to the base of the camera. After finding a good position on the back of the car, I can just put the camera on the car and the magnets will keep it stuck in place.

  To connect the camera to the smartphone at the front of the car, all we need is a long USB extension cable. Those are pretty cheap to come by and vary greatly in length. The one I purchased is a six-foot extension cable. The cable ran into the trunk, through the side of the back seat, then along the floor under the front seat, where it ran up to the dashboard and connected to the camera. Even though you might think otherwise, the trunk was able to securely close and lock even with the USB cable running into it.

  Step 3: Testing It Out

  If everything is connected correctly, and the USB Camera app is open, you should see the camera image on your phone! You may need to adjust the positioning of the webcam so that it captures the area you need it to display. Now, in a safe location, you can back up and you should be able to see what’s behind you! Again, let me stress not to use this as a commercial backup camera. However, it’s a great little backup camera to use in a pinch, and it will probably fit in your glovebox!

  Project 2

  Turning an Old Laptop

  into a Projector

  Intermediate

  Synopsis: Got an old unused laptop lying around? With a few tools, you can turn that old laptop into a projector and watch movies on your wall!

  Turning an old laptop into a projector - Larger images can be found on page 108 of photo glossary

  Parts & Tools Needed

  •Old unused laptop

  •Overhead projector

  •Screwdriver

  Step 1: Finding a Laptop

  As an IT professional, my family and friends ask me to fix their computer problems all the time. It’s actually something I enjoy doing. In some instances, however, it’s easier to buy a new computer instead of having the old one fixed. When that happens, I am quick to ask if I can have the old computer to repurpose. It’s amazing

  how many “broken” laptops I’ve acquired and have been able to restore or repurpose.

  For this project, I would only recommend using a laptop that has run its course, one that you don’t mind if it gets ruined. The only requirement is that it has to have a functioning screen and be able to play video and audio files. The laptop I used for this project was one a friend gave me because the charging port was broken and it would no longer charge. With a screwdriver, soldering iron, and some hot glue, I was able to get it charging again, and it was ready to be revived!

  Step 2: Preparing the Screen

  The trick for turning a laptop into a projector is all in the screen. That said, we need to extract the laptop screen and see what we have to work with. The screen is very fragile, so take these steps with caution. Most laptops have what’s called a “bezel” around the screen, and generally that can easily be unscrewed and removed. If you are unsure how to go about doing that, you can probably find instructions online for your specific laptop by doing a Google search for your laptop model followed by the words “tear down.” With the bezel removed, you should see how the laptop screen is attached to the laptop. Since every laptop is different, I can’t really go into specifics on how to remove it, but generally it’s basically removing a bunch of screws until you can carefully lift up the screen.

  The screen should still be connected to the laptop with wires. These should remain connected and unbroken. You’ll probably note that the screen actually consists

  of several different layers. The very back layer is generally a mirror and/or a backlight. The remaining layers are different filters and glass that produce the image. You’ll see different wires, ribbons, and other circuitry around the screen that deliver power data to it. For my screen, the circuitry was all at the top of the screen on the back, so all I had to do is carefully swing it out so that it’s not directly behind the screen. For some screens, the circuitry wraps around the top and side of the screen. If this is the case for you, this project may not work, as you won’t easily be able to remove the circuitry from the back of the screen.

  With the circuitry out of the way, the next thing I did was turn the computer back on. Normally, this is not something I would recommend doing, so again please be careful. Hopefully the screen still works and you can see images.

  At this point, we can lift up the different layers of the screen to see which ones are required for it to display and image and which ones aren’t necessary (such as the backlight). Basically, whenever you can lift up the screen and see your hand behind it while it’s still displaying an image, then that’s how you know what layers to keep.

  Step 3: Projecting the Video

  Now that we have the screen sorted out while retaining its ability to display videos, next we need a way to project the screen onto a wall. Back when I was in grade school, teachers had what were called “transparencies,” which were basically transparent plastic sheets that they could write on using dry-erase markers. Then they would use overhead projectors to project those transparencies onto the wall. I didn’t have an overhead projector, but I was able to purchase a working one off of Craigslist for twenty dollars.

  All I have to do now is take the

  screen (wires and circuitry still connected) and lay it on the face of the overhead projector. Luckily the width of my screen was the same width as the overhead projector, so it was a perfect fit! Turn on the computer, and then turn on the projector. Shine the projector on the wall and adjust the focus until you can clearly see what’s on your screen. Believe it or not, that’s it! Now just plug in a nice set of speakers and fire up a nice movie on the “big” screen! One thing you might notice is that there may be large light leaks below the screen from where it doesn’t quite cover the overhead projector surface. This can easily be fixed with some cardboard or construction paper to cover up those areas.

  Project 3

  CD-ROM Drive to 3D Printer

  Advanced

  Synopsis: Ever wanted a simple 3D printer of your own just to see what the 3D printing craze is about? Instead of shelling out hundreds of dollars for one, you can build a basic one using an Arudino microcontroller and some CD/DVD-ROM drives.

  Parts & Tools Needed

  •3 x Desktop computer CD-ROM or

  DVD-ROM drives

  •3 x Stepper motor drivers

  •1 x Arduino

  •1 x Desktop computer power supply

  •2 x Electrical box covers

  •1 x Generic 3D printing pen

  •1 x 22 Ohm resistor (value may vary depending on your 3D printing pen)

  •1 x NPN transistor

  •Various nuts, bolts, and spacers

  •Soldering equipment and wire

  Step 1: The Basic Idea

  I’m always surprised at how science fiction can inspire real life technology. In the original Star Trek and Star Trek: The Next Generation series, there is a device called a “replicator” that can materialize and reproduce many different objects nearly instantly.

  Twenty years later, current 3D printers aren’t that far from the technology imagined in the Star Trek replicators. In fact, there’s even a line of 3D printers called “Replicators.”

  3D printers are an amazing technological innovation. The concept of 3D printers is a relatively simple one. You have a three-axis device (X axis, Y axis, and Z axis) that lays down a thin layer of melted plastic (known as filament) and continues to build up tiers of plastic layers until an object is formed. While the 3D printer market is still somewhat expensive, and while 3D printing devices are pretty complex, we can use the basic prin
ciples to make our own basic 3D printer using parts that can be scavenged from a desktop computer. Depending on what spare computer parts you have lying around, you can build this project for less than one hundred dollars.

  Step 2: Disassembling the Drives

  A 3D printer requires having a platform that can move on three axes. Typically referred to as the X axis, Y axis, and Z axis, all this really means is that the platform can move up and down (Z axis), to the front and back (Y axis), and to the left and right (X axis).

  If you’re old enough to remember CD or DVD-ROM drives (a.k.a. optical drives) on desktop computers, they were known for having a “tray” that would slide out whenever a button was pressed so that you could insert your optical disk. Then if you pressed the button again, the “tray” would slide back in.

  The mechanism that makes this work is a little motor that moves the tray back and forth on a small track. This sliding motor tray mechanism is the perfect thing to use as a single axis for our 3D printer. And since there are three axes (X, Y, and Z), we will need three optical drives to match.

  Taking apart the optical drive was actually a lot easier than it looked. The first thing to do is pull out the plastic drive “tray” and snap off the front panel by pulling the bottom of it forward slightly and then pushing it up. When that’s done, flip the drive upside down and unscrew the bottom plate. Then it’s just a matter of prying off the plastic front panel and metal casing.

  CD-Rom Drive to 3D Printer - Larger images can be found on page 108 of photo glossary

  With the outer casing off, you can see all the beautiful guts that make this thing tick: motors, lasers, LEDs, gears, all sorts of cool stuff that can be scavenged for use in other projects. For this project, we’re interested in the metal mechanism with the spiral stepper motor and the plastic tray that slides back and forth on the track. The reason we want this specific part of the optical drive is because it offers a motor, track, and housing that can mechanically provide a smooth back and forth movement, which is ideal for a CNC axis. So you will need to disconnect any wires leading to the motor tray and separate it from the rest of the optical drive parts. You can remove the spindle motor (that spins the optical disk) from the tray if it is attached. You’ll also want to remove the laser and any other glass parts, magnets, or stray pieces from the laser sled to make sure that it doesn’t have anything that can hinder movement or mounting of other screws.

  Now that the sliding motor tray mechanism has been extracted, analyze the stepper motor and make sure that it has four wires that lead to the stepper motor. (Note that if your drive does not have a four-wire stepper motor, then this project will not work.) We need the motor wires to be at least six inches long. If the current wires are not that long, then they need to be extended. I decided to desolder the old motor wires and solder on four new wires. I used different color wires for each motor so that I could tell them all apart.

  Repeat this process for all three optical drives so that you have three bare motor trays; then you are ready for the next step.

  Step 3: Mounting the Motor Trays

  In order to achieve the X, Y, and Z axis movement, we will need to mount the sliding motor tray mechanisms onto some type of structure. Since we have three metal CD/DVD-ROM cases, I decided to use those as my mounting structure. Let’s start with the Y axis. The Y axis will go back and forth, so take one of the motor trays and mount it parallel to the length of the casing close to one end.

  Making sure it’s aligned as straight as possible, use some screws to mount it while also making sure the tray will still slide unhampered. Then use bolts, bolt spacers, and nuts to mount the slide tray to the metal casing.

  For the X axis, mount it perpendicular to the length of another optical drive case, again making it close to one end and aligning it as straight as possible. Then mount it using motherboard mounting screws as well. As for the Z axis, we will need to mount to the plastic tray sled of the X axis. In order to do this, I first mounted the Z axis to a salvaged metal plate (though you can use whatever you have available) using some bolts and spacers. Taking the entire Z axis plate, I attached it to the plastic tray on the X axis, again, using bolts and spacers.

  Once you have all the motor trays mounted, the final step is to attach the X axis and the Z axis to the Y axis. You want to mount the X axis perpendicular to the Y axis (it will look like an “L” shape) and adjust them so that the Z axis is aligned over the Y axis. Scrub through each axis, checking carefully to make sure none of them are overshooting or running into each other. After you have the alignment set, screw everything together. I ended up using an L Bracket, but you may be fine just screwing one case directly into the other case. As a finishing touch, I added a flat metal plate (another piece of scavenged metal) to the Y axis so that the metal plate gave the Y axis a flat surface to print things on.

  Step 4: Connecting the Electronics

  At this point we have the equivalent of a car with no ignition and no power. We have our three motor trays, but we need something that can control them and make them move. An “Arduino” is an electronic microcontroller that is very simple to use even for beginners. It can be used to control lots of different electronic components, such as LEDs, LCDs, buttons, sensors, switches, and, in our case, stepper motors. While the Arduino has the ability to control the stepper motors, it doesn’t have the capacity to provide enough energy to power them. To fix that problem, we will need what’s known as a stepper motor “driver” for each motor. In the diagrams, you can see how to wire up each motor driver for each axis.

  You may have noted that the motor drivers have two connections that are supposed to go to a “power supply.” This is a power source that provides extra power. Since I’m mostly using parts from scavenged computers, my power source is going to be an old computer (ATX) power supply. A computer power supply can output several different specific types of voltage. Despite their usefulness, let me warn you that computer power supplies can be dangerous if you mess with them and don’t know what you’re doing. Please use caution when utilizing them.

  When being used inside of a computer, a computer power supply turns on and off whenever you press a power button. In order to use a computer power supply without a power button, we need to bypass its power switch detection. Most common ATX computer power supplies have either twenty or twenty-four pins. Depending on which version you have, you can use the guide to determine where the “PC-ON” and ground pins are located. Then connect a ground pin to the “PC-ON” pin using a scrap piece of wire. Once the switch detection is bypassed, you can also use this wiring diagram to determine where the ground and 5v pins are so that you can connect them to the motor drivers. This is what we will be using to power our motors.

  Step 5: Hacking the 3D Pen

  The essence of most hobby 3D printers is the ability to melt plastic filament and extrude it into layers. This requires a device known

  as a “hot end” that takes plastic filament, melts it, and outputs it onto a platform. There are a lot of commercial grade “hot ends”

  on the market, but they can be somewhat expensive, and they’re kind of overkill given the homely nature of our build. Initially, I wanted to make my own “hot end,” but it ended up being a difficult thing to fabricate at home. So what I did instead was purchase a cheap 3D printing pen to see if I could tweak it and make it work as the “hot end.”

  The 3D printing pen I purchased was a very simple device. You plug it in, turn it on, insert the plastic filament, and then press a button to melt the filament and extrude it out the nozzle end. Testing it out, I found it worked as advertised.

  Now I just need to find a way to control it with the Arduino. Since it requires only the press of a button to melt and extrude the plastic, if we can trigger that button with the Arduino, then we should be able to program when it extrudes the plastic and when it doesn’t.

  What we want to do is switch the button on an
d

  off using an electrical signal. The best tool for doing that is a transistor, a device which switches electrical power off and on. In this case, I’ll be using an NPN transistor. Taking apart the 3D pen, I found where the extrude button was connected to the main circuit board. We can connect the Arduino to the NPN transistor, and then connect the NPN transistor to either side of the button. Since the Arduino outputs five volts of power and that might be too much power for the button, I added a twenty-two ohm resistor to limit the power. Depending on what 3D pen you use, the resistance may change.

  After reassembling the 3D pen and making a space for the wires to run through the casing, I mounted it to the Z axis sliding motor tray. You could use wire, bolts, and spacers, but what I ended up using was hot glue to hold it into place. Now, we’ve got the bones of our 3D printer! Next, we need to make it print something.

  Step 6: The Software

  This 3D printer, as well as most other 3D printers and CNC machines, runs off of a programming language called “G-code.” It essentially tells the X, Y, and Z axis which specific coordinates it needs to go to in order to make lines and arcs. G-Code is how a 3D printer knows what to create. If you want to 3D print a cube, the instructions for how to build that cube are converted into G-code and sent to the 3D printer. By itself, Arduino has a difficult time interpreting G-code, so we will need to install a G-code interpreter program called “Grbl.” You can download the version of Grbl specific to your Arduino model from GitHub4 and load it to your Arduino using a utility called “Xloader”5.