Vacuum Dragster Uses Syringes For Propulsion

September 17, 2020 by Lewin Day 16 Comments

Atmospheric pressure is all around us, and capable of providing a great deal of force when used properly. As Otto Von Guericke demonstrated with his Magdeburg hemispheres over 350 years ago, simply removing air from a chamber to create a vacuum can have astounding results. More recently, [Tom Stanton] has used vacuum to power a small 3D-printed dragster.

In the dragster build, a typical plunger syringe is plugged at the end, and the plunger pulled back. Atmospheric pressure acts against the vacuum, wanting to push the plunger back towards its original position. To make use of this, a string is attached to the plunger, causing it to turn a gear as it moves forward, driving the rear wheels through a belt drive. With the correct gear ratio on the belt drive, the dragster is capable of spinning its tires and shooting forwards at a quick pace.

The work is a great follow on from [Tom]’s earlier vacuum experiments, using syringes as small rockets. It reminds us of the classic CO2 dragsters from high school competitions, and would be a great project for any science class. Video after the break.

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Toy O-Scope Is Dope

September 12, 2020 by Brian McEvoy 12 Comments

Not many of our childhood doll and action figure’s accessories revolved around lab equipment except maybe an Erlenmeyer flask if they were a “scientist.” No, they tended to be toasters, vehicles, and guns. When we were young, our heroes made food, drove sexy automobiles, and fought bad guys. Now that we’re older, some of our heroes wield soldering irons, keyboards, and oscilloscopes. [Adrian Herbez] made a scale model oscilloscope that outshines the beakers and test tube racks of yesteryear. Video also shown below. Continue reading “Toy O-Scope Is Dope” →

Infinity Mirror At Warp Speed

September 11, 2020 by Brian McEvoy 10 Comments

Inventing often combines more than one old ideas into a new one. Even when the fused things are similar, the result can be more valuable than the sum of its parts. Unlike those analog watches with a digital clock below the face, when [Mojoptix] combined the re-reflecting properties of an infinity mirror with the image twisting qualities of a funhouse mirror, we get more than just a pair of mirrors. The resulting images look like a lot of fun. Warping one surface of two parallel mirrors doesn’t just alter the result a bit, because the planes feed off each other’s view, the final product is an exponentially skewed show.

Our host mounts a 3D printed ring with an hubward-facing strip of LEDs to an ordinary glass mirror. Over that, he designs four mated plates that hold semi-reflective film sheets in different shapes. The first is a hyperbolic paraboloid, but it’s probably easier to think of it as shaped like a Pringles chip (crisp). Once the light is applied, it looks like a bowtie made by a deranged god or the start of an infinite rabbit hole of light and reflection. To further the madness, he hits us with four shapes at once, so we hope you’ll take a moment to enjoy the video below.

This guy is no stranger to optics, and we’ve reported on a couple of other cool inventions that teach a concept through demonstration. His precision calipers demonstrate the Moiré effect, and his digital sundial capitalizes on parallel light beams.

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LEGO Delivers Corvette Experience On A Budget

September 8, 2020 by Tom Nardi 5 Comments

Many dream of tooling around in a high performance sports car, but the cost of owning, maintaining, and insuring one of them make it a difficult proposition. While this LEGO version of the Corvette ZR1 might not be exactly like the real thing, it’s 4-speed manual and electronic gauge cluster can give you a taste of the supercar lifestyle without having to taken out a second mortgage.

Built by [HyperBlue], this desktop speedster has more going on under the hood (or more accurately, the roof) than you might expect. While it looks pretty unassuming from the outside, once the top is lifted, you can see all the additional components that have been packed in to motorize it. The functional gearbox takes up almost the entire interior of the car, but it’s not like you were going to be able to fit in there anyway.

But the motorized car is really only half of the project. [HyperBlue] has built a chassis dynamometer for his plastic ride that not only allows you to “start” the engine with realistic sights and sounds (recorded from an actual GM LT1 V8 engine), but put the mini ‘Vette through its paces. With a virtual dashboard powered by the Raspberry Pi, you can see various stats about the vehicle such as throttle position, RPM, and calculated scale speed; providing a real-world demonstration of how the transmission operates.

While a LEGO sports car might not be quite as exciting as getting yourself a real project car, there’s something to be said for being able to rebuild your transmission without getting your hands dirty.

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Prop-Driven Cardboard RC Car Doesn’t Skimp On Performance

August 25, 2020 by Donald Papp 17 Comments

[Kryzer Channel] takes making a DIY RC car to a whole new level with this prop-driven electric car that is made almost entirely out of cardboard (YouTube video, also embedded below.) By attaching an electric motor with a push prop to the back of the car, [Kryzer] avoids the need for any kind of drive system or gearing. Steering works normally thanks to some scratch-built linkages, but the brake solution is especially clever.

Braking is done by having a stocky servo push a reinforced stub downward, out of a hole in the center of the car. This provides friction against the road surface. After all, on an RC car a functional brake is simply not optional. Cutting the throttle and coasting to a stop works for a plane, but just won’t do for a car.

Winding thread around metal components then saturating with CA glue makes a durable assembly.

Layers of corrugated cardboard and hot glue make up the bulk of the car body, and some of the assembly techniques shown off are really slick and make the video really worth a watch. For example, the construction of the wheels (starting around 2:24) demonstrates making them almost entirely out of cardboard, saturated with CA glue for reinforcement, with a power drill acting as a makeshift lathe for trimming everything down. A section of rubber inner tube provides the tire surface and a piece of hard plastic makes a durable hub. Wraps of thread saturated in CA glue, shown here, is another technique that shows up in several places and is used in lieu of any sort of fasteners.

The well-edited video (embedded below) is chock full of clever assembly and construction. Unsurprisingly, this is not [Krazer]’s first cardboard vehicle: their video channel has other impressive cardboard models and racers to show off.

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Scratch Built Subnautica Sub Explores The Pool

August 6, 2020 by Tom Nardi 6 Comments

In Subnautica, players explore an alien underwater landscape with the help of a number of futuristic tools and vehicles. [Robert Cook] found himself particularly enamored with the large submarine you unlock towards the later parts of the game, so much so that he decided to build his own real-life version.

Even though the RC version of the Cyclops [Robert] has designed is only big enough to explore swimming pool sized alien landscapes, it’s by no means a simple build. In fact, the sub’s internal watertight compartment holds an impressive array of electronics and systems that are arguably overkill for what’s essentially a toy. Not that we’re complaining, of course.

Beyond the electronics and a few key components, almost every part of the RC Cyclops has been 3D printed. From the bulkheads that cap off the internal watertight acrylic tube to the hull itself, there’s a lot of plastic aboard this ship. Which might explain why it takes nearly two kilograms of lead weight to get the sub close to neutral buoyancy. From there, a clever ballast tank arrangement made from a syringe and peristaltic pump allow the vehicle to dive and surface on command.

[Robert] is in the process of releasing the STL files for all the submarine’s 3D printed components, and has done an excellent job of documenting the roughly four months he’s spent working on the project in a series of videos on his YouTube channel. The videos contain a wealth of fascinating tips and tricks regarding DIY submersible vehicles, such as selecting the proper radio frequencies for maximum penetration through water and counteracting the permeability of 3D printed parts with a generous coating of epoxy.

Modern RC hardware makes it easier than ever to cobble together a “submarine”, but there’s still something to be said for a project that takes the long way around and actually implements features like a functioning ballast system.

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RC Car Becomes Cable Cam

July 19, 2020 by Al Williams 6 Comments

The prevalence of drones has made airborne photography much more widespread, especially among hobby photographers and videographers. However, drone photos aren’t without their problems. You have to deal with making the drone follow the shot which can be difficult unless you have a very expensive one. Worse, you can’t really fly a drone through heavily wooded or otherwise obstructed terrain.

[Makesome’s] friend faced these issues and wanted to buy a cable cam — a mount for the camera that could go back and forth on a cable strung between two trees or other structures. Instead of a design from scratch, they decided to cannibalize a cheap RC car along with an HP printer and the effect — as you can see in the video below — is pretty good.

Repurposing toys is an honored tradition and, after all, what do you need but a motor that goes forward and reverses? We can’t help but notice though that toy hacking is much easier now that you can 3D print custom widgets to connect everything together.

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