Trying To Build The World’s Fastest Roomba

October 22, 2022 by 7 Comments

A lot of people complain that Roombas are unreliable, poor at their job, or just plain annoying. Few people complain they’re not fast enough in a straight line. Regardless, [electrosync] set about building the world’s fastest Roomba for his own personal satisfaction.

For this challenge, [electrosync] set his own rules. The build must look like a Roomba, use two drive wheels, and one motor per wheel. It also has to maintain its vacuum functionality. After stripping down a used Roomba, he set about carving out space in the chassis for upgraded hardware. Brushed DC 775 motors were selected for the drivetrain, and these run through a 3:1 planetary reduction gearbox. 3D-printed mounts were then used to install the new motors in the existing chassis. New 3D-printed wheels completed the drivetrain. The original Ni-MH cells were replaced with a pair of 3-cell lithium polymer batteries for more power.

Measured with a Bluetooth GPS device, the upgraded Roomba achieved an impressive 36 km/h (22 MPH). With new wheel designs clad in urethane rubber and an improved anti-wheelie device, it hit a mighty 49 km/h (30 MPH). Adding 4-cell batteries pushed things further to 57 km/h (35 MPH), but the Roomba became difficult to control.

The gauntlet has been thrown down. Do you think you can build a faster Roomba? Time to get hacking! Video after the break.

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Lego Plays Electronic Drums

October 22, 2022 by 15 Comments

The ability to quickly try out an idea, and then expand and develop it, is what rapid prototyping is all about. Although we tend to think of 3D printing when rapid prototyping is mentioned, [Brick Technology] reminds us of the power of Lego, as he rapidly builds and improves an electromechanical drum machine.

Using Lego Technic pieces, he starts with a simple music box-style drum with moveable pins that pluck on spring-loaded levers, which in turn hit piezoelectric discs. The electronics side is simple, with the discs wired to a Roland sound module from an existing electronic drum kit. With the ability to instantly adjust, add and remove pieces, he quickly finds and fixes the problem of getting eleven hammer mechanisms together and working smoothly.

To get around the limited pin space on the drum and increase the length and variation potential of the rhythms, [Brick Technology] moved to a belt design that can accommodate significantly more pins. He also added an electric motor and various gearbox ratios for consistent and adjustable tempo. Together with his water vortex ball machine, he makes us think our workshops probably need a few hundred Lego Technic pieces.

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Build This Halloween-Themed TensEGGrity Sculpture

October 21, 2022 by 5 Comments

Tensegrity sculptures are fun things, and often sold as office desk toys or scientific novelties. You can build your own too, and [seabirdhh] has whipped up a fun holiday-themed version.

The first part to build is the egg-hat-stand. This consists of the base of the structure, with the “hat” of the egg character hanging in the center. The other half of the structure is built separately, with the rest of the “egg head” sitting in a cup in the bottom of the upper structure. A series of nylon threads are then tied between the components. These can then be tensioned to give the structure its shape, allowing the egg’s “hat” to hover above its “head”. [seabirdhh] passes the nylon threads through small pieces of rubber that allow the tension to be adjusted just right. Too little and the structure falls down, but too much, and it will bend over time. Tuning it carefully is key.

It’s a fun build, and a cheap way to experiment with tensegrity concepts at home. You can even use these same techniques to build a quadcopter, or apply them in the world of LEGO. Video after the break.

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Direction-Finding With Help From The Steam Deck

October 21, 2022 by 6 Comments

Direction-finding, or fox hunting, is a popular activity in ham radio circles where a group of people armed with radios attempt to locate a broadcasting source. Besides being a hobby for amateurs, it’s also a necessary tool in the belt of regulators who are attempting to track down violators of the air space. There are a lot of ways to figure out the precise location of a radio transmission, but this one manages to pull it off using both a boat and a Steam Deck, each armed with a software-defined radio.

This project comes to us from [Aaron] who is well known in the amateur radio circles for his SDR-focused Linux distribution called DragonOS; which has all the tools needed for a quality SDR experience, in this case KrakenSDR and DF Aggregator. He’s loaded everything up on a Steam Deck and left that in a secure location on the shore of a lake, while he carries second device with the same software with him on a boat. With the two devices listening for a specific signal, he’s able to quickly zero in on his friend on the shore who is broadcasting on the 70 cm band thanks to the help of all of these software packages.

While ham radio isn’t always known for being a youthful and exciting activity, the advent of software-defined radio and other digital modes seem to be shaking things up in that world. Certainly speeding around a lake on a boat is fun on its own as well, and a fox hunt like this can be done with something as small and simple as a Raspberry Pi too.

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Neodriver Ornament Brightens Up Christmas

October 21, 2022 by 11 Comments

Stores will sell you all kinds of gaudy holiday ornaments, but there’s nothing like the style and class achieved by building your own. [w3arycod3r] did just that, whipping up the fun and festive Neodriver Ornament.

It’s a battery-powered build, and runs off an rechargeable 18650 cell which provides several days of operation at a low duty cycle. An ATtiny85 is charged with sending out commands to various NeoPixel devices, from rings to rectangular arrays. [w3arycod3r] then designed various PCBs that could carry the hardware and battery in a well-balanced package that would hang nicely when suspended from a ribbon on a Christmas tree.

As is always the fun part with addressable LEDs, [w3arycod3r] whipped up some fun animations to suit. The 5×5 rectangular arrays of NeoPixels are able to deliver scrolling text, while another animation blips out the RNA sequence of everyone’s least favorite coronavirus, SARS-CoV-2. Getting everything to fit into a ATtiny85’s 8 KB of code space and 512 byte EEPROM was a challenge, but slimming down the Adafruit NeoPixel library and using direct AVR register manipulation in place of regular Arduino functions helped.

Overall, it’s a fun holiday build that looks great on the tree. Alternatively, consider making yourself some rheoscopic ornaments this holiday season. And, if you’ve whipped up your own fun holiday build, throw it on the tipsline!

ERRF 22: Recreator 3D Turns Trash Into Filament

October 21, 2022 by 28 Comments

In Back to the Future, Doc Brown returns to 1985 with a version of his DeLorean time machine that has been modified with technology from the future. After telling Marty they need to go on yet another adventure, Doc recharges the DeLorean’s flux capacitor and time circuits by tossing pieces of garbage into the slick Mr. Fusion unit mounted to the rear of the vehicle. The joke being that, in the future, you could simply head over to the local big box store and pick up a kitchen appliance that’s capable of converting waste matter into energy.

Unfortunately, we’re nowhere near powering our homes with banana peels and beer cans. But if the Recreator 3D is any indication, the technology required to turn plastic bottles rescued from the trash into viable PET filament for your 3D printer is all but upon us. While there are still some aspects of the process that could stand to be streamlined, such as fusing multiple runs of filament together into one continuous roll, the core concepts all seem to be in place.

The MK5Kit Mini is currently in development with LDO Motors.

Creator [Josh Taylor] made the trip out to the 2022 East Coast RepRap Festival to not only show off the Recreator 3D, a project he’s been working on now for over a year, but to get people excited about the idea of turning waste plastic into filament. It’s not necessarily a new concept, and in fact [Josh] says earlier efforts such as the PETBOT are what inspired him to create his own open source take on the “pultrusion” concept.

According to [Josh], actually printing with the recycled filament isn’t that different from using commercial PETG, though it’s recommended you lower your speeds. A nozzle temperature of around 260 °C seems to work best, with the bed at 70 °C. Interestingly, the filament produced by the process is actually hollow inside, so the most critical change to make is increasing your extrusion rate to about 130% of normal to compensate for the internal void.

The current revision of the Recreator 3D, known as the MK5Kit, can be assembled using several core components salvaged from a low-cost Ender 3 printer in addition to a number of parts that the user will need to print themselves. For those who’d rather not source the parts, [Josh] says he hopes to get formal kits put together sometime next year, thanks to a partnership with LDO Motors.

But ultimately, [Josh] says the most important thing to him is that the plastic is recycled instead of getting sent to a landfill or incinerator. So whether you build a Recreator 3D or come up with your own design, all are welcome to the PET Pultruders United Facebook group he’s created to discuss the finer points of turning plastic trash into treasure.

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Hackaday Prize 2022: Recycled Plastic Skateboard Decks Demonstrate Small-Scale Injection Molding

October 21, 2022 by 25 Comments

Injection molding is usually focused on high-volume production, but that doesn’t always need to be the case. The Recycled Plastic Skateboard Deck project centers on the use of injection molding for a relatively low-volume production line using open-source tooling.

RPSD is part of the Precious Plastics ecosystem and uses the existing and open-source shredder and extruder to turn locally-sourced plastic waste into melted plastic. The core of the tooling is in the aluminum CNC-machined top, bottom, and edge mold sections bolted to a thick steel support structure that give the skateboard deck its shape. The edge section defines the deck’s perimeter, and 64 cartridge heaters are inserted into it to bring the mold up to temperature. The mold is mounted on a scissor lift mechanism to allow it to be aligned with the extruder, and temperature control electronics are housed in a laser-cut metal enclosure, which is bolted to the base of the mold structure.

To be clear, this is not a cheap way to make a couple of skateboard decks, but rather a way for small shops to do injection molded decks in-house. At ~$7500 for the components of this relatively large mold, excluding the extruder, you’d still have to sell quite a few decks to make it economically viable.

Although small-scale injection molding has become a lot more accessible, the cost of machined metal molds will remain high for the foreseeable future. However, if you only need small, flexible parts, you could probably do it for under $50 using 3D printed molds and silicone.

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