No Need To Watch Your Tea, This Robot Does It For You

October 3, 2019 by Sharon Lin 15 Comments

For anyone who’s ever had to make their own tea, steeping it for the right amount of time can be a pain. That’s precisely the problem that the automatic tea brewing robot solves with its painless approach to brewing tea, built by Slovenian electrical engineering student [Kristjan Berce].

You can use the robot by setting a timer on the knob, at which point the robot raises it arm for the tea bag then dips in the water every 30 seconds until the time has passed. At the end of the timer, the bag is raised clear of the cup to end the brewing. It’s a remarkably simple design that almost evokes chindogu (the Japanese art of useless inventions) if not for the fact that the robot actually serves a useful purpose.

The components for 3D printing the robot are available online, consisting of a case, a container for the Arduino-powered electronics, the lever for holding the tea, and the gear that raises the lever up and down. The device also uses an integrated Li-Ion battery with an accessible charging port and integrated BMS. A 35BYJ46 stepper motor and ULN2003 driver are used to move the 3D printed mechanism. The device uses a potentiometer for setting the steeping time between 1 and 9 minutes, and there’s even a buzzer for indicating once the tea is done brewing.

The Gerber and Arduino code files are open-source for any hackers looking to make their own tea brewers; just take care they operate with “deadly punctuality”.

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Bearing-reinforced Stepper Tackles Hefty Axial Loads

August 11, 2019 by Sonya Vasquez 32 Comments

These days, it’s common among us hackers to load a stepper motor with forces in-line with their shaft–especially when we couple them to leadscrews or worm gears. Unfortunately, steppers aren’t really intended for this sort of loading, and doing so with high forces can destroy the motor. Fear not, though. If you find yourself in this situation, [Voind Robot] has the solution for you with a dead-simple-yet-dead-effective upgrade to get your steppers tackling axial loads without issue.

In [Voind Robot’s] case, they started with a worm-gear-drive on a robot arm. In their circumstances, moving the arm could put tremendous axial loads onto the stepper shaft through the worm–as much as 30 Newtons. Such loads could easily destroy the internal stepper motor bearings in a short time, so they opted for some double-sided reinforcement. To alleviate the problem, the introduced two thrust bearings, one on either side of the shaft. These thrust bearings do the work of redirecting the force off the shaft and directly onto the motor casing, a much more rigid place to apply such loads.

This trick is dead simple, and it’s actually over five years old. Nevertheless, it’s still incredibly relevant today for any 3D printer builder who’s considering coupling a leadscrew to a stepper motor for their Z-axis. There, a single thrust bearing could take out any axial play and lead to an overall rigid build. We love simple machine-design nuggets of wisdom like these. If you’re looking for more printer-design tricks, look no further than [Moritz’s] Workhorse Printer article.

Deducing Stepper Motor Wiring

July 25, 2019 by Al Williams 12 Comments

There are a lot of fun projects you can do with stepper motors salvaged from old printers or disk drives. However, it isn’t always clear how to connect to some strange motor with no markings or schematics. [Corvetteguy50] has a video showing his trick for working out the connections easily, and you can see it below.

The basic idea is simple. Using a special jig, he connects an LED across two random pins and spins the motor. If the LED lights, you’ve found a coil. You just don’t know which coil, yet. You can also short two wires and note when you feel resistance when you spin the shaft.

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Getting Hackers Excited About Cable Robots

July 18, 2019 by Tom Nardi 22 Comments

Ever since he looked into them as a way to water and care for his plants, [Tom] has been fascinated with cable robots. These high-flying gadgets can move in three dimensions over huge areas, provided you’ve got the ability to string up the aforementioned cables. But despite their flexibility, there hasn’t been a whole lot of hobbyist level development with these unique systems.

With his entry into the 2019 Hackaday Prize, [Tom] is hoping to change that. He’s learned a lot by building his own cable robots, and now wants to take it to the next level. Ideally with collaboration from the community, if he can find other hackers looking to outfit their homes or workshops with their own miniature sky cranes.

So what can you do with a cable robot? In the video after the break, [Tom] shows one of his creations dutifully transporting beer cans across the room and stacking them into a pyramid. Admittedly this isn’t a particularly useful capability (unless you run a bar, perhaps), but it does show the speed and dexterity of the system even when crossing large distances. If you’ve ever wanted to play the home edition of “Automate the Freight”, this one’s for you.

The system uses a trio of 36 volt stepper motors powered by a homebrew SLA7078 driver that [Tom] designed himself. Each stepper turns a geared-down spindle to which a strong cable is attached. With some clever routing around the workspace, careful orchestration of these small winches can be used to move the point where all the cables meet in 3D space. All that’s left is mounting your gadget of choice to this central point, and away you go.

We’ve seen the concept used commercially, but as far as hobbyist projects go, the most activity we’ve seen in this space would have to be the various room sized 3D printers that have popped up over the years. It would be interesting to see what kind of interesting projects the community could come up with if they had something with a little more muscle.

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Motorized Lens Controller Techs Up Your Webcam

July 11, 2019 by Lewin Day 13 Comments

If you’re familiar with the DSLR camera market, you’d know that modern lenses are works of technological art. Crammed full of motors and delicate electronic assemblies, they’re bursting with features such as autofocus, optical stabilization and zoom. [Saulius Lukse] has been experimenting with motorized lenses for webcam applications, and has built a controller to make working with them a snap.

The controller is capable of controlling up to 3 stepper motors, as well as a voice coil, which should be enough for the vast majority of lenses out there. Microstepping is supported, which is key for optical systems in which tiny adjustments can make a big difference. The controller speaks USB and I2C, and is now based on an STM32 chip, having been upgraded from an earlier version which used the venerable ATmega328. The board is designed to be as compact as possible, to enable it to neatly fit inside camera and lens assemblies.

The board has been used to successfully control an 18x zoom lens, among others. Combining such a lens with a webcam and a good pan and tilt mechanism would create a highly capable surveillance package, or an excellent vision system for a robot.

It’s not the first time we’ve seen work from [Kurokesu] in these parts – they’ve done work on pedestrian detection before, too.

Cycloid Drawing Machine Uses Sneaky Stepper Hack

June 15, 2019 by Lewin Day 16 Comments

Stepper motors are great for projects that require accurate control of motion. 3D printers, CNC machines and plotters are often built using these useful devices. [InventorArtist] built a stepper-based cycloid drawing machine, and made use of a nifty little hack along the way.

The machine uses a rotating turntable to spin a piece of drawing paper. A pen is then placed in a pantograph mechanism, controlled by another two stepper motors. The build uses the common 28BYJ-48 motor, which are a unipolar, 5-wire design. A common hack is to open these motors up and cut a trace in order to convert them to bipolar operation, netting more torque at the expense of being more complex to drive. [InventorArtist] worked in collaboration with [Doug Commons], who had the idea of instead simply drilling a hole through the case of the motor to cut the trace. This saves opening the motor, and makes the conversion a snap.

[InventorArtist] was able to create a machine capable of beautiful spirograph drawings, and develop a useful hack along the way. Reports are that a jig is in development to make the process foolproof for those keen to mod their own motors. We expect to see parts up on Thingiverse any day now. We’ve also covered the basic version of this hack before.

[Thanks to Darcy Whyte for the tip!]

Yet Another Robotic Rubik’s Solver

June 3, 2019 by Lewin Day 4 Comments

The Rubik’s Cube was a smash hit when it came out in 1974, and continues to maintain a following to this day. It can be difficult to solve, but many take up the challenge. The Arduino Rubik’s Solver is a robot that uses electronics and maths to get the job done.

The system consists of computer-based software and a hardware system working in concert to solve the cube. Webcam images are processed on a computer which determines the current state of the cube, and the necessary moves required to solve it. The solving rig is constructed from steel rods, lasercut acrylic, and 3D printed parts, along with an Arduino and six stepper motors. The Arduino receives instructions from the solving computer over USB serial link. These are then used to command the stepper motors to manipulate the cube in the correct fashion.

It’s no speed demon, but the contraption is capable of solving a cube without any problems. Manipulation of the cube is reliable and smooth, and the build is neat and tidy thanks to its carefully designed components. Of course, there are now even Rubik’s Cubes that can solve themselves. Video after the break.

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