A High Power Wood Rocket In 5 Days

May 23, 2021 by Danie Conradie 30 Comments

Getting started with model rocketry is relatively cheap and easy, but as you move up in high power rocketry, there are a few hoops to jump through. To be able to buy rocket motors larger than H (160 N·s / 36 lbf·s impulse) in the US, you need to get certified by the National Association of Rocketry. The main requirement of this certification involves building, flying, and recovering a rocket with the specific motor class required for the certification level. [Xyla Foxlin] had committed to doing her Level 2 certification with a couple of friends, thanks to the old procrastination monster, was forced to build a rocket with only 5 days remaining to launch data.

For Level 2 certification, the rocket needs to fly with a J motor, which is capable of producing more than 640 N·s of impulse. Fortunately [Xyla] had already designed the rocket in OpenRocket, and ordered the motor and major body, nosecone, and parachute components. The body was built around 2 sections of 3″ cardboard tubes, which are covered in a few layers of fiberglass. The stabilizing fins were laser cut from cheap plywood and were epoxied to the inner tube which holds the motor and passes through the sides of the outer tube. The fins are also fibreglassed to increased strength. For a unique touch, she covered the rocket with a real wood veneer, with the rocket’s name, [Fifi], inlaid with darker wood. The recovery system is a basic parachute, connected to the rocket body with Kevlar rope.

[Xyla] finished her rocket just in time for the trek out to the rocket range. She successfully did the certification flight and recovered [Fifi] in reusable condition, which is a requirement. There was nothing groundbreaking about [Fifi], but then again, reliability the main requirement. You don’t want to do a certification with a fancy experimental rocket that could easily fail. Continue reading “A High Power Wood Rocket In 5 Days” →

RC Car Gets Fan-Assisted Downforce To Slay Tesla’s 0-60 Times

May 23, 2021 by Lewin Day 26 Comments

Tesla have claimed that their upcoming new Roadster will post a sub-2 second 0-60mph time. While it’s backed up by little more than a shiny website at this stage, [Engineering After Hours] took the number as a target to beat with his RC fan car build. (Video, embedded below.)

We’ve seen an earlier prototype of this build before, with the first version generating enough downforce to successfully drive upside down. The new build has several modifications to maximise its lateral acceleration capabilities. The new build drives all four wheels, which are fitted with sticky tyres coated in traction compound for maximum grip. The main drive motor, along with the fan and skirt assemblies, are all mounted in the center of the car now to properly balance the aero loads across the axles and provide a stable weight distribution for fast launches.

The results are impressive, with the car posting a 0-60mph time of just 1.825 seconds. There’s likely still time left on the table, too, once the car can be tuned to launch harder off the line. We’d love to see a racing series of fan-equipped RC cars hit the track, too, given the amount of grip available with such hardware.

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Smart Guitar Will Practically Play Itself

May 23, 2021 by Kristina Panos 25 Comments

Playing the guitar is pretty difficult to do, physically speaking. It requires a lot of force with the fretting hand to produce clear notes, and that means pressing a thin piece of metal against a block of wood until the nerve endings in your fingertips die off and you grow calluses that yearn to be toughened even further. Even if you do get to this point of being broken in, it takes dexterity in both hands to actually make music. Honestly, the guitar is kind of an unwelcoming instrument, even if you don’t have any physical disabilities.

A Russian startup company called Noli Music wants to change all of that. They’re building a guitar that’s playable for everyone, regardless of physical or musical ability. Noli Music was founded by [Denis Goncharov] who has a form of muscular dystrophy. [Denis] has always wanted to rock out to his favorite songs, but struggles to play a standard guitar.

If you can touch the fretboard, it seems, you can whale away on this axe without trouble. It’s made to be easier to play all around. The strings aren’t fully tensioned, so they’re easy to pluck — the site says they only take 1.7oz of force to actuate.

Right now, the guitar is in the prototype stage. But when it’s ready to rock, it will do so a couple of ways. One uses embedded sensors in the fretboard detect finger positions and sound the appropriate note whether you pluck it or simply fret it. In another mode, the finger positions light up to help you learn new songs. The guitar will have a touchscreen interface, and Noli are planning on building a companion app to provide interactive lessons.

We have to wonder just how exactly this will be able to mimic the physics of guitar playing, especially since it’s designed with all players in mind. How satisfied will seasoned players be with this instrument? Can it do pull-offs and hammer-ons? What about slides? Do the sensors respond to bends? And most importantly, will the built-in speaker be loud enough to drown out the string vibrations? It seems to do just fine on that front, as you can see in the video below.

If the built-in speaker didn’t drown out the strings, it could make for some interesting sounds that stray outside the western chromatic scale, much like this LEGO microtonal guitar.

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Design An Electronic Catan Board In A Day

May 23, 2021 by Rich Hawkes 5 Comments

One of the things that makers sometimes skip over is the design of the project that they’re creating. Some of us don’t do any design at all, we just pants it. The design part of making something can take quite a while – there is sketching to do, as well as 3d-modelling and PCB creation. [Sam March] wanted to try and create something interesting where he did the design in a single day. The result is, or will be, a 3D printed, electronic, Settlers of Catan game board.

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Modifying Lights For DIY Ambiance

May 23, 2021 by Bryan Cockfield 13 Comments

The ESP32 and ESP8266 spread like wildfire a few years ago due to their small form factor, low price, and wireless capability. They didn’t just take over the DIY scene, though. Plenty of mass market products began to incorporate these tiny chips as well, which means that there are some interesting pre-made devices around that are ripe for modification. In this case, using an off-brand smart light bulb as a base for an semi-proprietary lighting setup.

The lighting in this build is a generic RGB light bulb with the ability to control its color over Wi-Fi. Since it has an ESP8266 chip in it, it can be made to work with Philips Hue lights with some minor modifications, allowing a much wider range of control than otherwise available. For this one, [Vadim] needed to pry open the bulb case to access the chip, then solder wires to it for reprogramming. It needed power during this step which meant plugging the resulting mess of wires back into a lamp socket, but after this step the new programming allows the bulb to be reprogrammed remotely.

After that step is complete, though, the generic bulb is ready for its inclusion into a Hue lighting system. In this case, [Vadim] is using diyHue, a Hue emulator that allows control of the bulbs without needing to use any cloud services, running on a BeagleBone. It’s a fairly comprehensive way of adding many different types and brands of bulbs to one system, and avoids any subscription models or the use of a cloud service, which is always something we can get behind.

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Adding Remote Controls To A Blackmagic Studio Camera Without Breaking The Bank

May 22, 2021 by Maya Posch 2 Comments

What to do when one ends up in the possession of a 4K studio camera, but without the requisite hardware and software to remotely control it? When [Glen Akins] ended up in this situation, he took the reasonable option here and developed his own knob-based remote control to adjust exposure and focus on the Blackmagic Designs Micro Studio Camera 4K. Without a remote control option, the only adjustment options are via fiddly small buttons on the camera itself, which wouldn’t have been a fun experience during the webcam usage that this camera would be used for.

This camera is normally controlled via the control channel on the SDI input which also handles the video output from the camera. For larger installations the proprietary ATEM software is commonly used, and there’s a $99 Arduino expansion board as well that’s apparently rarely stocked. With SDI not an option, the second option was LANC, which runs into pretty much the same issue with proprietary protocols and very expensive hardware.

Behind door number three is the more curious control option of the Futaba S.BUS protocol. Originally created for remotely controlling radio-controlled aircraft and similar remotely controlled systems, the thought here appears to be that this studio camera can also be used with systems that already have an S.BUS receiver, such as large drones.

With this S.BUS protocol having been reverse-engineered for a while now, it was a fairly straightforward procedure from there to create an MCU-based board with a lot of encoder knobs on it that map to a specific adjustment on the camera. The result of [Glen]’s labor can be found on GitHub.

Main image: The finished knob-box with the Blackmagic Designs camera. (Credit: Glen Akins)

Affordable Transilluminator Helps Visualize DNA

May 22, 2021 by Al Williams 2 Comments

If you want to examine the results of gel electrophoresis — and who doesn’t — you need a transilluminator. These devices can be quite pricey, though, so you might want to check out [Gabriel St-Pierre’s] plans to make an affordable blue-light version. You can see a video about the device below.

Using a UV filter, an Arduino Nano, an LED strip, 3D printing, and some mechanical items, it looks like this is a very easy project if you need such a device. There are a few miscellaneous parts like a hinge and some mirror material, but nothing looks too exotic.

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