Author: Lewin Day

1969 Articles

Slow Races On A Pinewood Derby Track Built From Scratch

May 20, 2022 by 18 Comments

Pinewood derby racing is a popular pastime for scouting groups and many others besides. [Mr Coster] whipped up his own track with the assistance of some 3D printed parts, and used it to run a competition with a fun twist on the usual theme.

The track starts with a pair of MDF panels, on to which some strips are placed to act as guides for the racers. There’s also a release mechanism built with hinges and a pair of dowels that ensures both racers start the competition at exactly the same time. To give the track a nice transition from the downward slope to the horizontal, a series of curved transition pieces were designed in Fusion 360, 3D printed, and added to the course.

As for the competition, [Mr Coster] decided to eschew the usual focus on outright speed. Instead, students were charged with building the slowest possible car that could still complete the course. Just for the fun of it, though, the kids were then given one day to modify their slowest cars to compete in a more typical fastest-wins event. It gives the students a great lesson in optimizing for different performance parameters.

You might be old-school, though, and want to ruin the fun by taking it all way too seriously. Those competitors may wish to consider some of the advanced equipment we’ve featured before. Alternatively, you could run a no-holds-barred cheater’s version of the contest. Video after the break.

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Flexible Grip For Hammer Made With 3D Printing Pen

May 19, 2022 by 16 Comments

When it comes to putting a flexible grip on a tool, you might reach for a self-fusing silicone tape or other similar product. However, [Potent Printables] has discovered you can easily create a flexible grip using a 3D-printing pen and some flex filament.

In this case, a hammer first gets a layer of blue painters tape wrapped around its wooden handle. This serves as a base layer to promote good adhesion. A simple paper template was then printed as a guide for creating the graphics on the flexible grip. Flexible filament was fed through the 3D pen, with the red and black details of the graphics printed first. Then, white flex filament was used to make the rest of the flexible grip. A wood burning tool was then used to smooth out the first layer of flex filament, before a second layer was added on top.

The result is a flexible white grip on the hammer which is stuck fast, likely due to shrinkage as the plastic cooled after printing. We’ve seen some other creative grips made with 3D printing before, too. Video after the break.

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Hacking The Logitech Z906 Speaker System

May 19, 2022 by 36 Comments

The Logitech Z906 is a well-rounded 5.1 surround sound system. It’s capable of putting out 1000W in peak power, and can decode Dolby Digital and DTS soundtracks as you’d expect. It’s intended to be used as the heart of a home cinema system and used with a central command console. However, [zarpli] figured out the device’s serial secrets and can now run the device in a standalone manner.

As it turns out, the Z906 uses a main control console that speaks to the rest of the hardware over a DE15 connector (also known as the DB-15). [zarpli] realized that the hardware could instead be commanded by just about any device with a serial port. Thus, a library was whipped up that can be readily used with an Arduino to control all the major functions of the Z906. Everything from volume levels to effect modes and channel assignments can be commanded by microcontroller. As a finale, [zarpli] shows off the hardware playing a multi-channel composition without the console connected, with his own hardware running the show instead.

If you’ve got a Logitech Z906 or similar unit that you wish to automate, you might find this work useful. It’s also a good inspiration for anyone contemplating hacking away at the console ports on other hardware. Video after the break.

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Defeat Your Car’s Autostop Feature With A Little SwitchBot

May 18, 2022 by 203 Comments

These days, many new cars come with some variant of an “auto-stop” feature. This shuts down the car’s engine at stop lights and in other similar situations in order to save fuel and reduce emissions. Not everyone is a fan however, and [CGamer_OS] got sick of having to switch off the feature every time they got in the car. So they employed a little robot to handle the problem instead.

The robot in question is a SwitchBot, a small Internet of Things tool that’s highly configurable for pressing buttons. It’s literally a robot designed to press buttons, either when remotely commanded to, or when certain rules are met. It can even be configured to work with IFTTT.

In this case, the Switchbot is set up to activate when [CGamer_OS]’s phone is placed in phone mount, where it scans an NFC tag. When this happens, Switchbot springs into action, switching off the autostop function. It was set up this way to avoid Switchbot hitting the button before the car has been started. Instead, simply popping the smartphone in the cradle activates the ‘bot.

It’s a rather creative use of the SwitchBot. They’re more typically employed to turn on dumb devices like air conditioners or heaters that can otherwise be difficult to control via the Internet. However, it works well, and means that [CGamer_OS] didn’t have to make any permanent modifications to the car.

The design of the SwitchBot reminds us of the Useless Box, even if in this case it has an actual purpose. Video after the break.

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One Coder Is Porting Portal To The Nintendo 64

May 18, 2022 by 10 Comments

When Portal came out in 2007, developers Valve chose not to release the groundbreaking title on an obsolete Nintendo console long out of production. Nobody cared at the time, of course, but [James Lambert] is here to right that wrong. Yes, he’s porting Portal to the N64.

The port, or “demake,” as [James] calls it, has been under construction for some time. The project has posed some challenges: Portal was developed for PCs that were vastly more powerful than the Nintendo 64 of 1996. Thus, initial concerns were that the console wouldn’t be able to handle the physics of the game or render the recursive portal graphics.

However, hard work has paid off. [James] has chipped away, bit by bit, making improvements to his engine all the while. The latest work has the portals rendering nicely, and the companion cube works just the way you’d expect. There’s also a visible portal gun, and the engine can even render 15 recursive layers when looking through mirrored portals. Sixteen was too much.

Of course, there’s still lots to do. There’s no player model yet, and basic animations and sound are lacking. However, the core concept is there, and watching [James] flit through the not-quite-round portals is an absolute delight. Even better, it runs smoothly even on original Nintendo hardware. It’s a feat worthy of commendation.

We had no idea what [James] had in store back when we featured his work creating real-time shadows on N64 hardware. Now we know! Video after the break.

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3D Printed Linear Actuator Is Cheap And Strong

May 18, 2022 by 27 Comments

Motors are all well and good for moving things, but they’re all about the round-and-round. Sometimes, you need to move something back and forth, and for that a linear actuator will do the trick. While they can be readily sourced for under $50 online, [Michael Rechtin] genuinely felt like reinventing the wheel, and managed to whip up a 3D-printed design that costs under 20 bucks.

The basic design is simple, consisting of a small motor which is geared down through several stages using simple spur gears. The last gear in the train is tasked with turning a lead screw which drives the arm of the linear actuator back and forward.

For simplicity, [Michael] used a 24V brushed DC gearmotor for its low cost and the fact it already has a step-down gearbox integrated into the design. It’s paired with a couple more 3D-printed spur gears to provide even more torque. Instead of a fancy lead screw, the build instead just uses a quarter-inch bolt sourced from Home Depot, which can be had much cheaper. This pushes a 3D-printed arm back and forth thanks to a nut stuck in the arm. It’s all wrapped up in a neat-and-tidy 3D-printed housing. The design is able to push with a force of roughly 220 lbs. For a more practical idea of its strength, it can readily crush an empty soda can.

The video on the design is great, showing how important features like limit switches are added, and how the wiring can be neatly hidden away inside the housing. We’ve seen [Michael’s] work before, too, like strength testing various types of 3D printed gears. Video after the break.

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Sunrise Keyboard Looks The Part

May 18, 2022 by 9 Comments

If you’ve been to a bar sometime since the 1930s, you’ve probably spied someone drinking a Tequila Sunrise. It’s a drink that mimics the beautiful colors of the dawn. In much the same way, so does this Sunriser keyboard build from [crashl1445].

Built for a high-school engineering project, the build looks resplendent with its yellow case, paired with yellow, orange and pink keycaps to produce the wonderful sunrise aesthetic. The build relies on an Elite-C v4 microcontroller, an off-the-shelf device specifically designed for building custom keyboards. As you might guess from the name, it features a USB-C port, serving as a modernized alternative to the Arduino Pro Micro for custom keyboard builders. KTT Rose switches are used as per [crashl1445’s] own preference, and there’s even a rotary encoder which acts as a volume knob, installed right by the arrow keys. The case is printed in several parts on a Prusa Mk3+, as the keyboard wouldn’t fit entirely on the build plate as a single piece.

The best thing about building your own keyboard is that you can design it entirely to suit your own preferences and aesthetic; we think [crashl1445] did a great job in this regard. If you’re cooking up your own sweet keyboard build, don’t hesitate to let us know!