Troy Hawkins (AKA “tomatoskins”) had come across an interesting wooden perpetual calendar, which used a trio of rings to show the month, day, and day of the week. The only problem is that it’s manually operated, subject to human error or neglect. So when he decided to construct his own version, he added an Arduino to take care of this task for him.
His automated design uses a trio of stepper motors to turn three rings via independent gearing systems. Correct rotation is regulated by an RTC module that links up to the Nano inside. Magnets embedded within each wheel’s gears trigger a Hall effect sensor to further ensure that “date data” is properly on display.
Whether you work in meters, feet, inches, or kilometers — or any number of other units corresponding to properties that you need to convey — conversions are a fact of life when making things. While this could mean pulling up a Google tab or flipping open a Machinery’s Handbook and doing a few hand calculations, neither is particularly convenient for shop use.
As an alternative, Kaleb Clark over at element14 came up with a dedicated desktop conversion calculator using an Arduino Uno and Cherry MX switches in a matrix arrangement as the main input method. A rotary encoder is also implemented to swap between functions and output is via a 4×20 LCD screen.
Although the device still needs a bit of programming work to be called “complete,” it’s currently able to handle an impressive variety of conversions.
The Physical Twin travels on a three-wheeled chassis and mounts a four-axis arm with a brush. An operator controls the arm to dip the brush into an onboard paint container, and can then manipulate it for application.
The controller consists of a joystick for movement as well as a mini version of the arm. Four potentiometers measure arm input angles, which are duplicated on four corresponding servos on the robot. A pair of Arduino Mega boards are used for the setup — one on the mobile robot and another in the remote unit.
You can see the device in action in the videos below, showing off direct operation and the ability to play back prerecorded movements.
As you work on a project, lighting needs change dynamically. This can mean manual adjustment after manual adjustment, making do with generalized lighting, or having a helper hold a flashlight. Harry Gao, however, has a different solution in the form of a novel robotic task lamp.
Gao’s 3D-printed device uses a USB camera to take images of the work area, and a Python image processing routine running on a PC to detect hand positions. This sends instructions to an Arduino Nano, which commands a pair of small stepper motors to extend and rotate the light fixture via corresponding driver boards.
The solution means that he’ll always have proper illumination, as long as he stays within the light-bot’s range!
One of the simplest ways to make a mobile robot involves differential steering, where two wheels move at different speeds as needed to turn, and a roller on the back keeps it from tipping over. The MrK_Blockvader is an excellent take on this type of bot, demonstrated in the first clip below. It features a nice blocky body comprised out of 3D-printed parts, wheels driven by tiny gear motors, and an integrated roller ball on the back.
The MrK_Blockvader is controlled via an Arduino Nano, along with an nRF24 breakout that allows it to receive signals from a radio transmitter unit. The build includes LED lighting as well as a piezo buzzer for all the beeps and boops. It can also take advantage of various sensors if necessary.
The eventual goal is to use the MrK_Blockvader in a network of robots, hinted at in the second video with a worker at its side.
Colin Furze decided that he needed a potato cannon for his DIY screw tank, and after making a manually loaded version, he automated the process.
What he came up with uses a pair of linear actuators to push the barrel forward under Arduino control, allowing a potato-projectile to drop into the device’s chamber assembly. After a short delay, it closes up again, cutting the roundish vegetable into a cylindrical plug. Flammable gas then enters via a solenoid valve for a carefully regulated amount of time.
With the gas mixed, the cannon is then fired, and a single button press starts the process over again. The powerful cannon creates a mess in his test area after a few shots, actually taking a plug out of the mattress he used to absorb the impact. It should be quite impressive once mounted on the screw tank, though it’s a project that you probably shouldn’t try at home.