[Chris] has put together a robot head that is impressive at first sight. [Chris’] robot, Walter II, becomes even more impressive when you realize that [Chris] built every single part from scratch. Many of Walter’s parts were created using machines [Chris] built himself. Walter is a robot neck and head. His upper neck joint is based upon three bevel gears.Two steppers drive the side gears. When the steppers are driven in the same direction, Walter’s head nods. When they are driven in opposite directions, the head turns. The end result allows Walter’s head to be panned and tilted into almost any position.
A second pair of motors raise and lower Walter’s neck via a chain drive. What isn’t immediately visible is the fact that a system of gears and belts maintains the tilt on Walter’s head as his lower neck joint is actuated. For example, if Walter’s head is facing directly forward with his neck raised, one would expect him to be facing the ground when the neck is lowered. The gear/belt system ensures that Walter will still be facing forward when the neck joint reaches its lower limit. All this happens without any movement of the neck motors. [Chris] definitely put a lot of thought into the mechanical design of this system.
Continue reading “Walter is a Robot Head Built From Scratch.”
Children of the information age are doomed to have the worst handwriting just for lack of use if nothing more. But some students at Olin College harnessed technology to find a solution to that problem. Meet Herald, a CNC machine that can produce beautiful calligraphy.
The machine uses a gantry to move the writing tip along the X and Y axes. The flexible-nib calligraphy pen is mounted on a sprocket which rotates the tip onto the writing surface, taking care of the third axis. The rig was beautifully rendered from their CAD drawings, then tweaked to ensure the smoothest motion possible before the quintet of Sophomores began the physical build.
The drive hardware is very simple yet it produces great results. It uses an Arduino along with three stepper motor drivers. There are also limiting switches to protect the hardware from runaway code. The software interface designed by the team lets the user cut and paste their text, and select a font, font size, alignment, etc. It then converts the text to G-code and pushes it to the Arduino where the GRBL package takes care of business.
Don’t miss the device in action, writing out a [Langston Hughes] work in the clip after the break.
Continue reading “Handwriting suck? Build a machine to do it for you”
[IronJungle] had an old hard drive taking up space in his workshop, so he took it apart and wrote in to remind us how useful these old pieces of hardware can be. Aside from offering up incredibly strong magnets and donut-shaped mirrors, HDDs also come with a reliable stepper motor in tow.
He pulled theold drive apart, wiring up two of the stepper motor pins to a pair of the drive’s header pins. This allowed him to easily access the signals produced by the stepper simply by hooking up a small JST connector to the back of the drive.
From there, he can use the drive for any number of purposes. For the sake of discussion, [IronJungle] used it to flash an LED as seen in the video below – something he willingly admits is no great feat. However, stepper motors can be used for in a wide array of projects, both simple and complex. Be sure to share your favorite use for salvaged HDD motors in the comments.
Continue reading “Repurposing old HDD Components”
What do you do if you’re given a gigantic ancient printer? If you’re [IronJungle], you throw that printer on your workbench and salvage all the parts you can. After coming across a few stepper motors in an old Oki printer, [IronJungle] decided to automate an Etch-a-Sketch with the help of a PIC microcontroller and H-bridge chip to log the ambient temperature on an Etch-a-Sketch display.
After [IronJungle] was finished figuring out his stepper motor circuit, the only thing left to do was to add a thermometer. For this task, he chose a very cool one-wire digital thermometer that carries power and data over the same wire.
In the video after the break, you can check out [IronJungle] playing with his new Etch-a-Sketch temperature logger with a shot glass of hot water and a cold can of holy water. There’s no scale or graph lines drawn on this Etch-a-Sketch temperature logger, but [IronJungle] has a few more things planned for this rig. We can’t wait to see those plans come to fruition.
Continue reading “Logging temperatures with an Etch-a-Sketch”
Get ready to join a band. Just follow the guide over at the Moppy project page and you’ll have your very own floppy drive instrument.
The name is a mashup between Musical and Floppy. By using an Arduino UNO as a translator, you can command an array of floppy drives with a musical keyboard (think piano). The head on each floppy drive is controlled by a stepper motor which will put out some sweet sounds if driven at just the right frequency. The lower notes tend to fair a bit better than the high range. One great example of this is the Imperial March theme as heard after the break.
Once you get the base system up and running, it’s time to think of some alternate interfaces. Sure, you can obvious things like toy keyboards. But wouldn’t it be more fun to make it fruit controlled?
Continue reading “Moppy lets you play your floppy drives”
[Roy] is getting to the end of his second CNC mill project and finally seeing some results. Here you can see a bear he milled in some floural foam.
The project started out as an Arduino-based pen plotter. It move the pen along one axis, and the drawing surface along another, with the third axis allowing the pen to be lifted and repositioned. With that in his back pocket he went all out and began what he calls the Mark II. He used T-slot aluminum for the frame, which really helped when it came to aligning the linear rod supports for each axis. After a lot of drilling, and tapping he managed to bring each axis on line one at a time. A pre-fab CNC driver kit drives the stepper motors, making them groan as they do their work. hear it for yourself in the test video after the break were the machine is first tested as a pen plotter.
Continue reading “Pleasing results from a CNC mill project”
[Vinnie] has a wonderful old clock from his grandmother; it’s an exquisite antique with a real mechanical movement and a charming set of bells that ring every hour. Unfortunately, those chimes are a bit of a disturbance to neighbors at 2 o’clock in the morning. Previously, [Vinnie] had been stopping the clock every evening, and hoped he would remember to start the pendulum in motion 12 hours later. This was a chore, so he decided to automate the process.
The build is simple and clever; a small stepper motor is mounted in the clock just underneath the pendulum. Every 12 hours, the stepper motor moves a lever and slowly stops the pendulum over the course of a dozen or so seconds, silencing the clock movement. Twelve hours later, the motor turns again setting the pendulum in motion.
The parts count for this build is very low – basically just an ATmega88, a Darlington array to drive the stepper, and a 32.768kHz crystal. We can think of a few friends and relatives with loud clocks in their house, so we might have to build a few of these to give away.
Take a look at the demo video after the break to see how [Vinnie] stops his grandmother’s clock every night.
Continue reading “Quieting a pendulum clock every night”