Check out this robot arm capable of handwriting which is orders of magnitude clearer than our own. It was built by [Patrick Barnes] as contract work for a campaign to raise funding for research into Duchenne Muscular Dystrophy.
Don’t miss the video after the break which starts off with the satisfying whine of some serious stepper motors. Judging scale from this image is a bit tough, but [Patrick] tells us that the entire assembly stands almost fourteen inches tall and the arm has a reach of around twenty inches. The demonstration shows off it’s abilities by drawing a Hilbert Curve. From watching the action you’ll realize that, though this arm and hand look fantastic, this is really a SCARA plotter. The wrist and fingers are for looks only, providing a place where the felt-tipped pen can be mounted (held flush to the paper with a rubber band). Whether that’s a disappointment or not, the precision and look of the machine bring it very high marks. It could take a bit of a lesson in penmanship from another we’ve seen though.
Continue reading “Handwriting robot arm is a little stiff-wristed”
Here’s a fun way to break up the monotony in the old cubicle farm. The Mug Plotter will let you expertly inscribe your coffee vessel with a different witty saying or design for each day of the week. If it looks familiar that’s because it’s loosely based on the non-flat drawing robot, the Egg-Bot.
[Teed] built the machine using laser cut plywood parts. He starts off the build description with the griping technique. There are two parts to this, one is concave and fits in the mouth of the mug. The convex side grips the bottom edges of it. These parts go on the frame along with the slide and thread rods which hold the stylus. A servo motor is along for the ride, providing the ability to lift the marker when necessary.
You can see in the clip after the break that there’s a bit of oscillation in the rig when one of the steppers starts turning really fast. But it doesn’t seem to affect the look of the design very much at all.
Continue reading “Mug Plotter based on the Egg-Bot”
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”
This art installation makes a video game from the 1970’s popular again. It can be found at the Dublin Science Gallery’s GAME exhibition. Museum goers step up to the coin-op style game cabinet and the onlookers will see how they’re doing as the landing is plotted on this board.
Hardware details are a bit hard to come by but we hear that there will me more on the build posted soon. For now the Flickr set is the best source of information. From reading the captions we know that a set of three Mac minis run everything. There are also a few close-ups and a video overview of the drive hardware which you can see mounted on the upper left of the image above. We can tell you that this is a string plotter similar to builds we’ve seen in the past. The telemetry data from the Lunar Lander game is converted to instructions and fed directly to that device. See it in action in the clip after the break.
Continue reading “Art installation plots every game of Lunar Lander that is played”
This polar graph draws some amazing shapes on a dry erase board. Part of that is due to the mounting brackets used for the two stepper motors and the stylus. But credit is also due for the code which takes velocity into account in order to plan for the next set of movements.
The Go language is used to translate data into step commands for the two motors. This stream of commands is fed over a serial connection between the RPi board and an Arduino. The Arduino simply pushes the steps to the motor controllers. The inclusion of the RPi provides the horsepower needed to make such smooth designs. This is explained in the second half of [Brandon Green’s] post. The technique uses constant acceleration, speed, and deceleration for most cases which prevents any kind of oscillation in the hanging stylus. But there are also contingencies used when there is not enough room to accelerate or decelerate smoothly.
You can catch a very short clip of the hardware drawing a tight spiral in the video embedded after the break.
Continue reading “Raspberry Pi driven Polargraph exhibits high precision drawing ability”
This center pivot pen plotter is an interesting take on the idea, and manages to somewhat simplify the fabrication when compared to a gantry-style built.
Normally we’d see a gantry that travels on two rails, with a print head that moves along its length. Here the gantry is anchored on just one side, with a chain driven system to rotate it along the plotting surface. The print head uses a fine-point felt-tipped marker. It still travels along the arm as you would expect, and can be tilted away from the paper for repositioning.
What was made easier in hardware ends up adding to software complexity. The benefit of a traditional system is that it uses X and Y coordinates to plot a design. The pivot of this mechanism means that as the print head moves further from the center of the machine, the distance between each pixel is magnified. But the clip after the break proves that this issue has been solved.
Continue reading “Center pivot pen plotter”
At first look we thought this was a plotter, but it’s really more of a dot matrix (or line matrix) printer. [Bruno] whipped this up using parts from a DVD optical drive. It is capable of moving the pen along the Z and X axes, and feeding the paper along the Y axis.
The video after the break shows the machine printing Megaman, an image perfectly suited to the low-resolution pixels this can put out. But even without the high-pixel counts you might get from a thermal printer, we just love the look of this one. And who doesn’t have an optical drive sitting around just waiting to be hacked? It looks like the one part you’re going to have to source is the stepper motor and geared feed wheel that moves the paper.
Continue reading “Self-feeding pen printer”