Scratch Built Tricycle Maximizes Fuel Efficiency

May 16, 2021 by Bryan Cockfield 27 Comments

While the bicycling community is welcoming an influx of electric bikes, there’s a group of tuners on the fringes that are still intent on strapping gas motors of all sizes to bicycles and buzzing down the roads in a loud and raucous fashion. Kits are readily available and are much cheaper than comparable e-bike kits, and with a little bit of work it’s possible to squeeze a lot of excitement from these small motors. With a lot of work, though, you might end up with something like this incredibly fuel efficient and fully customized reverse trike from [Paul Elkins].

The entire goal with this build was fuel efficiency, so the plan is to eventually enclose the vehicle in aerodynamic fairings, most likely using his favorite material, Coroplast. The frame itself is completely hand-made from square tube and welded by [Paul] himself to his own custom specifications. He bolts on a suspension and custom steering rack with levers to control the two front wheels, and the small engine and gas tank are attached to the back above the single drive wheel. The engine hadn’t been started in ten years, but once he got it all put together, it started right up and he was able to take his latest prototype out on the road for a test drive.

While the build isn’t completely finished, the video below (eleventh so far in the build log) is far enough along to show the fruits of years of [Paul]’s labor. It’s taken a while to get a design that worked like he wanted, but with this iteration, he finally has what he was looking for.

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3D Printing Espresso Parts

May 15, 2021 by Bryan Cockfield 28 Comments

Virtually any hobby has an endless series of rabbit holes to fall into, with new details to learn around every corner. This is true for beekeeping, microcontrollers, bicycles, and gardening (just to name a few), but those involved in the intricate world of coffee roasting and brewing turn this detail dial up to the max. There are countless methods of making coffee, all with devout followers and detractors alike, and each with its unique set of equipment. To explore one of those methods and brew a perfect espresso, [Eric] turned to his trusted 3D printer and some compressed gas cylinders.

An espresso machine uses high pressure to force hot water through finely ground coffee. This pressure is often developed with an electric pump, but there are manual espresso machines as well. These require expensive parts which can withstand high forces, so rather than build a heavy-duty machine with levers, [Eric] turned to compressed CO2 to deliver the high pressure needed.

To build the pressure/brew chamber, he 3D printed most of the parts with the exception of the metal basked which holds the coffee. The 3D printed cap needs to withstand around nine atmospheres of pressure so it’s reasonably thick, held down with four large bolts, and holds a small CO2 canister, relief valve, and pressure gauge.

To [Eric]’s fine tastes, the contraption makes an excellent cup of coffee at minimal cost compared to a traditional espresso machine. The expendable CO2 cartridges only add $0.15 to the total cost of the cup and for it’s simplicity and small size this is an excellent trade-off. He plans to improve on the design over time, and we can’t wait to see what he discovers. In the meantime, we’ll focus on making sure that our beans are of the highest quality so they’re ready for that next espresso.

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Reverse-Engineering An Unknown Microcontroller In E Ink Displays

May 15, 2021 by Bryan Cockfield 11 Comments

For a monochrome display where refresh rate isn’t particularly important, there’s almost no better option than an E Ink display. They’re available in plenty of sizes and at various price points, but there’s almost no option cheaper than repurposing something mass-produced and widely available like an E Ink (sometime also called eInk or ePaper) price tag. At least, once all of the reverse engineering is complete.

[Dmitry Grinberg] has been making his way through a ton of different E Ink modules, unlocking their secrets as he goes. In this case he set about reverse engineering the unknown microcontroller on the small, cheap display show here. Initial research showed an obscure chip from the ZBS24x family, packaged with a SSD1623L2 E Ink controller. From there, he was able to solder to the communications wires and start talking to the device over ISP.

This endeavor is an impressive deep dive into the world of microcontrollers, from probing various registers to unlocking features one by one. It’s running an 8051 core so [Dmitry] gives a bit of background to help us all follow along, though it’s still a pretty impressive slog to fully take control of the system.

If you happen to have one of these price tags on hand it’s an invaluable resource to have to reprogram it, but it’s a great read in general as well. On the other hand, if you’re more interested in reverse-engineering various displays, take a look at this art installation which spans 50 years of working display technologies.

Random Robot Makes Random Art

May 14, 2021 by Bryan Cockfield 4 Comments

For the price of a toothbrush and a small motor with an offset weight, a bristlebot is essentially the cheapest robot that can be built. The motor shakes the toothbrush and the bristle pattern allows the robot to move, albeit in a completely random pattern. While this might not seem like a true robot that can interact with its environment in any meaningful way, [scanlime] shows just how versatile this robot – which appears to only move randomly – can actually be used to make art in non-random ways.

Instead of using a single bristlebot for the project, three of them are built into one 3D printed flexible case where each are offset by 120°, and which can hold a pen in the opening in the center. This allows them to have some control on the robot’s direction of movement. From there, custom software attempts to wrangle the randomness of the bristlebot to produce a given image. Of course, as a bristlebot it is easily subjected to the whims of its external environment such as the leveling of the table and even the small force exerted by the power/communications tether.

With some iterations of the design such as modifying the arms and control systems, she has an interesting art-producing robot that is fairly reliable for its inherently random movements. For those who want to give something like this a try, the code for running the robot and CAD files for 3D printing the parts are all available on the project’s GitHub page. If you’re looking for other bristlebot-style robots that do more than wander around a desktop, be sure to take a look at this line-following bristlebot too.

Thanks to [johnowhitaker] for the tip!

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Mind-Controlled Flamethrower

May 12, 2021 by Bryan Cockfield 16 Comments

Mind control might seem like something out of a sci-fi show, but like the tablet computer, universal translator, or virtual reality device, is actually a technology that has made it into the real world. While these devices often requires on advanced and expensive equipment to interpret brain waves properly, with the right machine learning system it’s possible to do things like this mind-controlled flame thrower on a much smaller budget. (Video, embedded below.)

[Nathaniel F] was already experimenting with using brain-computer interfaces and machine learning, and wanted to see if he could build something practical combining these two technologies. Instead of turning to an EEG machine to read brain patterns, he picked up a much less expensive Mindflex and paired it with a machine learning system running TensorFlow to make up for some of its shortcomings. The processing is done by a Raspberry Pi 4, which sends commands to an Arduino to fire the flamethrower when it detects the proper thought patterns. Don’t forget the flamethrower part of this build either: it was designed and built entirely by [Nathanial F] as well using gas and an arc lighter.

While the build took many hours of training to gather the proper amount of data to build the neural network and works as the proof of concept he was hoping for, [Nathaniel F] notes that it could be improved by replacing the outdated Mindflex with a better EEG. For now though, we appreciate seeing sci-fi in the real world in projects like this, or in other mind-controlled projects like this one which converts a prosthetic arm into a mind-controlled music synthesizer.

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Fertilizing Plants With A Custom 3D-Printed Pump

April 25, 2021 by Bryan Cockfield 20 Comments

For all but the most experienced gardeners and botanists, taking care of the soil around one’s plants can seem like an unsolvable mystery. Not only does soil need the correct amount of nutrients for plants to thrive, but it also needs a certain amount of moisture, correct pH, proper temperature, and a whole host of other qualities. And, since you can’t manage what you can’t measure, [Jan] created a unique setup for maintaining his plants, complete with custom nutrient pumps.

While it might seem like standard plant care on the surface, [Jan]’s project uses a peristaltic pump for the nutrient solution that is completely 3D printed with the exception of the rollers and the screws that hold the assembly together. With that out of the way, it was possible to begin adding this nutrient solution to the plants. The entire setup from the pump itself to the monitoring of the plants’ soil through an array of sensors is handled by an ESP32 running with help from ESPHome.

For anyone struggling with growing plants indoors, this project could be a great first step to improving vegetable yields or even just helping along a decorative houseplant. The real gem is the 3D printed pump, though, which may have wider applications for anyone with a 3D printer and who also needs something like an automatic coffee refilling machine.

Heating A Home With Sunlight… And Water

April 22, 2021 by Bryan Cockfield 66 Comments

The sun is a tremendous source of energy, and while photovoltaic panels are an easy way to harvest some of that energy especially now that prices for them are incredibly low, there are plenty of other ways to tap into that free energy as well. [Engelbert] was looking for alternative ways to heat his house since traditional methods were prohibitively expensive, and ended up building a heat exchanger using solar-heated water to cover his home heating needs. (Google Translate from Dutch)

The system uses several large roof-mounted hot water heating panels. The heat captured by them is then pumped into an underground pipe network which is able to warm up a large area of earth in the summer. In the winter, that heat is able to be extracted back out of the earth and used to heat his home. The system includes almost three kilometers of pipe which are buried two meters below grade, so this will probably not be a weekend project, but it still cost much less than the €80,000 to install gas heating in his home.

[Engelbert] is able to use this self-built system to keep his home and another smaller building at a constant 23°C all year. He actually overbuilt the system slightly and has since disconnected almost half of the pipes, but we certainly understand the desire to over-engineer things around here. The only problem he has had is with various government entities that are slow to adopt energy-efficient systems like these. Perhaps the Dutch government can take some notes from the Swiss when it comes to installing geothermal systems like these.

Thanks to [Jero] for the tip!