Jackson Pollock was famous for his unique style of splattering large blobs of paint across a canvas, and it was this technique that JBV Creative was trying to imitate. But rather than working by hand to painstakingly dip a brush into paint and then flinging it many times over, he wanted to build a robot that could do this task for him while still creating art.
The main part of the Flingbot, the name JBV gave to his system, is comprised of a catapult arm that is capable of both rotating and adjusting how far it can throw paint. A servo motor at the back pulls an elastic band a certain amount based on the desired distance, and a second one releases a pin to perform the launching action. As another parameter for generating abstract art, the silicone scoop itself can bend to change its shape. Every servo motor is connected to a single SSC-32U servo controller board that receives commands from an Arduino Uno.
Paint gets dispensed from one of the 12 total reservoirs that each has a gravity-feeder out its base with a servo motor that controls how much paint is deposited into the scoop. Once all of the paint has been collected for a launch, the Uno adjusts the angle and tension of the arm and finally releases the paint.
To see how JBV Creative constructed this robot and a glimpse of the wildly unpredictable artwork it produced, check out his video below as well as his project write-up here.
Public art installations are a great way to express your creativity while simultaneously sharing it with others. Niklas Roy, a maker who builds interactive art installations in Berlin, Germany had the idea to create a machine that lets people draw pictures and then share them digitally too, which he calls the VEKTORKOLLEKTOR. Designed in collaboration with Kati Hyyppä, the project consists of two parts: a joystick for operating the device and a large pen plotter to draw on a piece of paper.
The joystick assembly was made with a classic arcade joystick and a pair of arcade pushbutton switches, all placed within a small enclosure. These components are connected to a central Arduino Uno that also has an SD card for saving drawings and a small TFT display that shows a virtual drawing of what’s on the page. The Uno communicates with a secondary Arduino Nano board in order to control the rotations of the two X/Y DC gear motors and thus the position of the drawing utensil. Positional data is gathered from a single optical encoder situated on each axis.
One great aspect to saving what people draw as a series of vectors is that they can be shared digitally and recreated in a variety of formats. Roy was able to get someone to create an Inkscape extension for converting drawings into SVG files, and some were even used to paint murals with an even larger spray can plotter.
YouTuber Robert Dunn (known as Under Dunn) had just received a large box of loose cylindrical battery cells and therefore wanted to join them together to create a large battery pack. Ordinarily, this is accomplished by utilizing a specialized type of tool called a battery spot welder that is used to tack nickel strips onto the terminals. But Dunn didn’t want to spend the money on a new one, so he built his own DIY version using only an old microwave, an offcut of copper, some wire, and an Arduino Uno with a solid-state relay attached to control the current discharge timings.
Dunn began by extracting the transformer from the microwave and cutting it open to expose the coils within. As a quick refresher, transformers step voltage up or down by using a pair of opposing coils inside of a magnetic field, which also causes the current to increase or decrease in an inversely proportional manner. Because Dunn wanted to maximize the current, he replaced the smaller coil with an even smaller one made from 6-guage wire that could handle the extremely high current.
An Arduino was used in conjunction with a solid-state relay module to pulse the current going into the transformer. Its circuit also contained a seven-segment LED module that showed the number of milliseconds the transformer would be on, as well as a red button for activating it. Timing could be adjusted with a rotary potentiometer.
Once everything was wired up and placed into a wooden enclosure, Dunn tested out his DIY battery spot welder by pressing the button, and it worked as expected.
Tiny mobile robots are a blast to use. They are fast, fun, and can even be autonomous. However, they all suffer from a similar issue: batteries, which are notorious for running out of charge quickly when the motors are kept spinning for too long. To address this issue, Mike Rigsby came up with a small robot that has a simple “brain” but has the ability to never run out of power.
Rigsby’s robot, named Roamer, starts off on a charging station that is comprised of a large metal plate on the bottom and a small, energized bump rail. The bot contains a spring under its base that contacts the plate, and its front plate contacts the bumper. Therefore, when the two meet, the circuit is completed, and Roamer can determine if it needs to charge.
Roamer’s onboard Arduino Uno is paired with a motor shield that drives both continuous servo motors to both give forward/backward motion and turn side-to-side. There is also a photoresistor on the top of the robot that is used to sense if the room is dark or light. If it is bright enough, the rover will begin its normal pattern of moving in random directions until it needs to top off its batteries, but a dark room causes it to “sleep” until the light returns.
Roamer is a clever demonstration of how simple materials can be implemented to create a robot that can theoretically never run out of power. You can view this timelapse of it below as well as see how the rover was created here on Hackaday.io.
Ordinarily, producing complex waveforms on microcontrollers requires precise adjustments within code in order to work, and this can become quite tedious. Additionally, having to wire up physical inputs such as potentiometers for quick tuning adds a lot of sprawl to a project. This is partially what inspired Kevin, who runs the DIY Electromusic website, to construct a small, Arduino-based device that allows users to sketch the waveform they want outputted via PWM.
The main components of this project are the ILI9488 TFT shield that fits onto an Arduino Uno, along with an amplifier/speaker and an optional output filtering circuit to clean up the audio. Kevin’s unit takes in a MIDI note on the Uno’s RX pin and passes it through a wavetable function that applies the currently displayed waveform on the screen to the note being requested.
Kevin also made a slight modification to the previously mentioned project by replacing the wavetable with a series of five sliders that correspond to various parameters for a MIDI granular synthesizer. His analog version had five large potentiometers that plugged into the analog input pins on an Uno, but this newer version greatly cleaned things up and gives more room for experimentation.
To read more about these innovative audio control projects, you can view them on Kevin’s website here and see a quick demo below.
After becoming frustrated at his lack of archery skills and not wanting to spend an eternity practicing getting better, Shane Wighton (known as Stuff Made Here on YouTube) sought to build a rig that could automatically correct his aim for the perfect shot every time. The device is comprised of a rigid sleeve that fits over the wearer’s forearm, along with a pair of stepper motors that can adjust where the bow is pointing either vertically or horizontally via a rack-and-pinion. These motors are driven by an Adafruit microcontroller running CircuitPython and a couple of motor driver modules that provide the necessary current. But that’s not all, he also created a small rig that uses an Arduino Uno and servo motor to autonomously fling targets into the air.
Target tracking is achieved by having a set of eight OptiTrack cameras around the room monitor the space for tiny gray spheres, and through the use of a special triangulation algorithm, they can accurately determine where both the arrow is pointing and where the target is in 3D space. Initially, the system missed all of its shots due to poor software and the wrong kind of bow, so Wighton completely rewrote his program and switched to a compound bow instead.
Once everything had been corrected, the software was able to predict where a flying target would end up according to its speed, and thus had the ability to intercept it. The Auto-Aiming Bow could also hit a target the size of a 3mm-wide circle with scary precision.