Drawing on walls is fine for children, but adults tend to get bored quickly with such antics. Even more so when they realize who is responsible for cleaning up afterwards. Instead, consider delegating those duties to a friendly helper by the name of Fumik, as [engineer2you] has done.
Fumik, who looks like a cute little jellyfish, can draw pictures up to 5 meters wide and 3 meters high, making for a massive canvas. Powered by an Arduino Mega 2560 outfitted with a CNC shield, a pair of stepper motors drive pulleys with toothed belts to move Fumik to various positions along the wall. Another smaller stepper motor is used to drive the pen forwards and backwards as needed. Fumik can be programmed to trace out various designs in SVG format. These must be converted to code and programmed into the Arduino, at which point Fumik can begin work, drawing on the wall with its pen.
It’s a fun build, and based on photos shared by [engineer2you,] Fumik is quite able at drawing clean and neat designs without a lot of smudging or jagged lines. As a bonus, it’s easy to swap out the pen, so multicolored designs can be drawn in multiple passes.
Most of us have probably seen a video of a sand drawing table at work, in which a steel ball — magnetically-coupled to a gantry under a layer of sand — lazily draws geometric patterns with utter precision and zen-like calmness. That’s all well and good, but [Mark Rehorst] thinks it can also be interesting to crank up the speed and watch the ball plow through sand just as physics intended. There’s a deeper reason [Mark] is working at this, however. Faster drawing leads to less crisp results, but by how much, exactly? To answer this, [Mark] simply ran his table (which is named The Spice Must Flow) at both fast and slow speeds and documented the results.
These two images show the difference between running the table at 100 mm/s versus 500 mm/s. The slower speed is noticeably crisper, but on the other hand the faster speed completed the pattern in about a fifth of the time. [Mark] says that as the ball aggressively accelerates to reach target speeds, more sand is thrown around over existing lines, which leads to a loss of detail.
Crisper detail, or a faster draw? Which is “better” depends on many things, but it’s pretty clear that [Mark]’s cat finds the fast version more exciting. You can see [Mark]’s table at high speed and the cat’s reaction in the video, embedded below.
Can it crawl? Can it climb? Can it roll? Can it skate? Can it draw? Naminukas by [Mykolas Juraitis] can do all of those things, and it is the size of a winter boot. Roving robots generally fall into one locomotion category, and the fanciest are amphibious. We categorize this one as transforming between three modes.
The first mode is like an inch-worm and a robot arm. Using a vacuum cup at the hub of each wheel, it sticks one end to the ground then heaves itself in the direction it wants to go and repeats. Its second form is a two-wheel balancing robot, which is the fastest configuration, and it can even carry things on its suckers. For the finale, it can hybridize all the tricks and use a camera dolly like a skateboard. One end sticks to the dolly, and the other is a propulsion wheel.
Naminukas is not just about scooting around the floor, because it can use tools with enough dexterity to write legibly on a whiteboard, climb walls, and even move around the ceiling. If these become sentient, there will be no place to hide, except a room with shag carpet, and is that any way to live?
[Ivan] seems to enjoy making 3D printed vehicles with tracks. His latest one uses 50 servo motors to draw patterns in the sand at the beach. You can see it work in the video below. Well, more accurately you can see it not work and then work as the first iteration didn’t go exactly as planned.
An Arduino Mega 2560 provides the brains and the whole unit weighs in at almost 31 pounds, including the batteries. We didn’t see Ivan’s design files, although it wouldn’t be hard to do your own take on the robot.
The BrachiGraph project consists out of two parts, the hardware design for a servo-driven drawing arm (pen plotter) and software utilities (written in Python) that allow the drawing arm’s servos to be controlled in order to convert a bitmap image into a collection of lines that can be used to draw an image resembling the original, in a variety of styles. All of the software and designs needed to make your own version can be found on the Github page for the project.
Considering an estimated €14 worth of materials for the project, the produced results are nothing short of amazing, even if the principles behind the project go back to the Ancient Greek , of course. The basic hardware is that of a pantograph, which provides the basic clues for how the servos on the plotter arm are being driven.
The main achievement here is definitely that of minimalism, with three dirt-cheap SG-90 microservos along with some bits of wood, a clothes-peg or equivalent, and of course a pen providing a functional plotter that anyone can assemble on a slow Sunday afternoon from random bits lying around the workshop.
Not all of us have CNC machines, laser cutters and 3D printers, and I’ll bet most of us didn’t start out that well equipped. The low-cost drawing machine that [jegatheesan] made for his daughter reminds us that you can prototype, and then make a functioning mechanical Da Vinci with very basic materials and mostly hand tools. He also wrote his own drawing software, with an interface that has its own simplicity.
There really are a lot of things to like about [jegatheesan]’s project. He first works out the math himself by doing something the likes of which we’ve all enjoyed, digging out the old school trigonometry and algebra books for a refresher. Then he got started on his prototype, made using a cardboard tube for the main support and straws and safety pins for the drawing arms. He already had a motor shield for his Arduino but it supported only 2 servos, so he made his own 3-servo shield. In the end, the prototype told him he had to redo some calculations, allowing him to move on to the final machine.
One thing we can say about the final machine is that hot glue must truly be the maker’s connect-all — you won’t find many screws here. Even the servos are held in place with copious quantities of glue. And the mechanism for lifting the pen is also quite clever. The whole thing is mounted on two vertical guide rods, so that it can easily slide up and down. To get it to actually move up and down, he glued a toy car wheel off-center on a servo arm. When the servo turns, the off-center wheel acts like a cam, pushing down on the wooden base to either lift the machine up or lower it down, depending on where the wheel is in its rotation.
See his hackaday.io page for the full step-by-step development process. But first check out the videos below to see how impressive such a simply made machine is in action.
We’ve seen robotic artists before but most of them are either cartesian-based or hanging drawbots. This is a full-fledged Sharpie-wielding robotic arm that draws with dots giving its work an impressionistic feel.
The actual robotic arm is a stock Interbotix WidowX. The folks over at Phantom Multimedia wrote some custom software that takes a graphic and breaks it down into a 1-bit representation. The code then goes through the bitmap at random, picking points to draw on the medium. The hard part of this project was figuring out how to translate the 2D image into 3D robotic arm movements. Since the arm has several joints, there are multiple mathematical solutions for arm position to move the marker to any given point. The team ended up writing an algorithm to determine the most efficient way to move from point to point. Even so, each drawing takes hours.
As if that wasn’t enough, the software was then reworked to probe positions. Instead of automatically moving the arm to a predetermined point, the arm is manually moved to a location and the data retrieved from the servo encoders is used to determine the position of a probe at the end of the arm. Each point taken in this manner can then be combined to generate a 3D model.