Scratch-Built RC Excavator Is A Model Making Tour De Force

September 16, 2022 by Dan Maloney 20 Comments

Some projects just take your breath away with their level of attention to detail. This scratch-built RC-controlled model excavator is not only breathtaking in its detail, but also amazing for the materials and tools used to create it.

We’ve got to be honest, we’ve been keeping an eye on the progress [Vang Hà] has been making on this build for a few weeks now. The first video below is a full tour of the finished project, which is painstakingly faithful to the original, a Caterpiller 390F tracked excavator. As impressive as that is, though, you’ve got to check out the build process that starts with fabricating the tracks in the second video below. The raw material for most of the model is plain gray PVC pipe, which is sliced and diced into flat sheets, cut into tiny pieces using a jury-rigged table saw, and heat formed to create curved pieces. Check out the full playlist for a bounty of fabrication delights, like tiny hinges and working latches.

We can’t possibly heap enough praise onto [Vang Hà] for his craftsmanship, but that’s not all we love about this one. There are tons of helpful tips here, and plenty of food for thought for more practical builds. We’re thinking about that full set of working hydraulic cylinders that operates the boom, the dipper, and the bucket, as well as the servo-operated hydraulic control valves. All of it is made from scratch, of course, and mostly from PVC. Keep that in mind for a project where electric motors or linear actuators just won’t fill the bill.

If this construction technique seems familiar to you, it could because we featured a toolbox made out of similarly processed PVC pipes back in June.

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Inexpensive Reading Glasses Become Stereoscope

September 13, 2022 by Jenny List 17 Comments

It’s an unfortunate consequence of growing older, that no longer are you able to read the print on a SOT-23 package or solder a QFN without magnification. Your eyes inexorably start to fail, and to have any hope of continuing a set of reading glasses is required. We have this in common with [Niklas Roy], who noticed while shopping for cheap reading glasses that their lenses were of surprisingly good quality. The result of this observation was a stereoscope made from card and a few euros worth of eyewear.

In the tradition of [Niklas]’ work it has a high level of attention to detail, which manifests itself here in a parametric web-based template generator to produce a result tailored to your glasses. It’s a fairly straightforward trapezoid shape, with a compound lens made from two sets of glasses drilled and held back-to-back with zip ties.

It served as a project for a group of children, and of course because stereo cameras are a relative rarity he also investigated taking his own pictures by moving a smartphone for left and right eye perspectives. It seems the youngsters had a lot of fun.

These lenses hadn’t come up on our radar until now, but like many goodies in a dollar store they’re certainly something to take a look at. Maybe not as a stereoscope for everyone though, some of us can’t see what the fuss is about.

LEGO Rig Makes Pretty Water Vortexes

September 1, 2022 by Lewin Day 6 Comments

LEGO and its Technic line is a great way to learn about all kinds of mechanical things, but it’s also just a whole lot of fun to play with. We suspect the latter reason is what got [Brick Technology] to pursue creating a trippy water vortex with the building toy.

The first design uses a transparent plastic sphere as a water vessel. Inside the sphere is placed a small turbine, turned from the outside via a magnetic coupling. This means the sphere can remain intact, with no holes required, nor complicated seals which can leak. It works well, and produces a vortex when the turbine is spun by a regular LEGO motor. A second attempt elects to rotate the entire sphere itself. Small LEGO wheels are then used to hold the sphere in place on the rapidly spinning turntable. The results are impressive, creating a large and relatively well-formed vortex.

Naturally, though, the video saves the best for last. The big transparent sphere is installed in a rig that surrounds it completely. The sphere itself is spun up thanks to wheels installed on two different axes. This allows the sphere to be spun in various directions under command from a PlayStation controller, creating more complicated vortexes and flow patterns. A set of swiveling casters are provided to hold the sphere in place as it rotates in various directions, and are damped with springs and rubber bands to stop the rig shaking itself apart.

Is there much purpose to this? Well, not on the surface level, no. However, it would certainly make one heck of a rig for shaking up cocktails. Or, if for some reason you need a noisy yet attractive centrifugal separator, maybe this could do the trick. Continue reading “LEGO Rig Makes Pretty Water Vortexes” →

Simple Hacks To Make LEGO Train Track Out Of Other Pieces

August 30, 2022 by Lewin Day 27 Comments

LEGO trains are fun to play with, but as with any model train, you so seldom have enough track to fulfill your greatest desires. YouTuber [brick_on_the_tracks] has come up with some creative ideas of his own to make track compatible with Lego trains using other techniques.

TRAINED LEGO PROFESSIONALS! DO NOT ATTEMPT IN REAL LIFE!

The most straightforward is to use the LEGO fence piece, first released in 1967. They can be laid in two rows, four studs apart, and they’ll serve as perfectly functional train track. It’s a 100% legal building technique as per the official LEGO rules, too. Official track pieces can be linked up by placing them on a 1-stud-high booster. [brick_on_the_tracks] argues that it’s up to nine times cheaper than using official track, but it depends on how you’re building your layout, and you need to take into account the need for a base plate.

On the sillier side of things, it’s actually possible to use mini-figures as track, too. Again, it’s a 100% legal technique, though the trains don’t run as smoothly compared to the fence track. It’s very amusing, though, and could be a fun addition to a build you’re taking to a local LEGO convention.

If you’re really strapped for cash though, you can go as far as using cardboard. It’s not legal in the LEGO world, and it’s pretty basic, but you could literally make up a layout using nothing but a craft knife and pizza boxes. We’ve actually featured other LEGO train hacks before, like this neat automatic decoupler design.

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High Speed RC Jet Car Is A Harsh Teacher

August 28, 2022 by Danie Conradie 8 Comments

Making machines go fast has always been a seemingly unavoidable impulse for humans. With the advent of radio control, it’s possible to get a taste of the rush without putting your life and too much money on the line. In the spirit of speed, [James Whomsley] strapped a jet turbine engine to an RC car, and learned some hard lessons along the way.

The car started as a four-wheel drive electric race car, but [James] removed most of the drive train components and mounted the jet turbine engine on a pair of 3D printed struts. Originally intended for large-scale RC planes, the little jet engine produces about 120 N of thrust. To allow the car to stop, [James] kept the drive shafts and connected them to a centrally mounted disk brake unit.

For the first high-speed test runs, James added a vacuum-formed shell and a pair of large vertical stabilizers for high-speed stability. On the 3rd test run at a local racetrack, the car got up to 190 km/h (118 MPH) before it veered off the track and crashed. Fortunately, the chassis and engine only sustained minor damage and were easy to repair.

James rebuilt the car with a lower engine to reduce the center of gravity and added an electronic gyro in an attempt to stabilize the car at high speed. Time ran out, and he wasn’t able to test the car before taking it to a high-speed RC event held on a runway. This led to another crash when the car again veered off the track after badly oscillating. After checking the onboard footage, [James] discovered the receiver had experienced a loss of signal, and an incorrect fail-safe setting made the engine go full throttle. After more tests, James also found that excessive play in the steering mechanism had caused the gyro to induce oscillations.

Although this car failed in the end, [James] intends to take the lessons learned into a new high-speed car build. [rctestflight] also did some testing with an EDF-powered RC car recently, and used a drone flight controller for high speed stability. This is not [James]’ first foray into speed machines, having previously experimented with a rocket plane.

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Mahmut's kid in a helmet, riding the go-kart outside on pavement

Hoverboard Go-Kart Build Is A Delight To Watch

August 14, 2022 by Arya Voronova 4 Comments

Hoverboards have been an indispensable material for hackers building their own vehicles in the last few years. [Mahmut Demir] shows how he’s built a hoverboard-powered go-kart for his son. Unable to hack the board’s firmware, he instead set out to reuse the hoverboard without any disassembly, integrating it into the go-kart’s frame as-is. This build is completely mechanical, distinguished in its simplicity – and the accompanying six minute video shows it all.

This go-kart’s frame is wood and quite well-built, with the kind of personal touch that one would expect from a father-son gift. Building the vehicle’s nose out of a trashcan gave us a chuckle and earned bonus points for frugality, and the smiley face-shaped wheel is a lovely detail. As for the ‘hoverboard reuse’ part, the board is pivoted backward and forward, just as it normally would be. Rather than feet, the kart uses a lever that’s driven with two pedals through a pulley-string arrangement, giving granular speed control and the ability to reverse. It’s a clever system, in fact we don’t know if we could’ve done it better. You can see [Mahmut]’s son wandering in the background as [Mahmut] goes through the assembly steps — no doubt, having fun doing his own part in the build process.

[Mahmut] tells us he’s also added a remote off switch as a safety feature, and we appreciate that. We’ve seen hoverboards in go-kart builds before, as well as rovers, e-bikes, robot vehicles, and even mobility platforms. Truly, the hoverboard is a unicorn of hacker transportation helpers.
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Up Your Desk Toy Game With This 3D Printed Escalator

August 9, 2022 by Tom Nardi 21 Comments

Let’s be real, nobody needs a tiny motorized escalator for their desk. But now that you’ve seen it, can you really say you don’t want one of your own? The design comes our way from [AlexY], and is actually the logical evolution of a manually-operated version released previously. But for our money (and 3D printing time), we’d definitely go with this new motorized variant.

While the core mechanism is largely the same, the powered unit uses a N20 geared motor and an 18650 cell. There’s no fancy motor controller here — just flip the switch and you’ve got 30 RPMs worth of stair-steppin’ action. When you’ve run the cell down, and you will, there’s an onboard TP4056 charging module to keep the good times rolling.

[AlexY] hasn’t had a chance to document the build process for the motorized version of the escalator, but as most of the parts are compatible with the manual version, you should be able to figure it out by referencing the earlier assembly guide.

Hot squirted plastic not your thing? We’ve previously seen a wooden escalator designed to keep a Slinky in motion for as long as it takes for you to realize you could be using your skills for something more constructive.

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