Author: Zoe Skyforest

3791 Articles

LEGO Pole Climbers Are Great Study In What It Takes To Go Vertically Upwards

July 23, 2021 by 3 Comments

Climbing a pole with a robot might sound complicated and hard, but it doesn’t have to be. This video from [Brick Experiment Channel] demonstrates multiple methods of doing the job while keeping things simple from a mechanical perspective. (Video, embedded below.)

The first method uses a gravity locking design, where the weight of the battery pack is placed on a lever arm to increase the normal force on the wheels gripping the pole. Increasing the length of the lever arm, reducing the angle of the crawler, or adding grippier tyres can all be used to increase the grip with this design. The final design of this type is able to climb most of the way up an 8 meter flagpole without too much trouble.

The next version uses rubber bands to help add tension to grip the pole. This too works well and makes it to the top of the flagpole. The final build is a circulating design that looks truly wild in action, and winds its way to the top of the flagpole as well.

It’s great to see the experimental method of designing these Lego creations, as well as seeing how they do in the wild. [Brick Experiment Channel] has been featured here before, too.

Continue reading “LEGO Pole Climbers Are Great Study In What It Takes To Go Vertically Upwards” →

A Simple LEGO Automatic Transmission

July 22, 2021 by 9 Comments

The automatic transmission in your average automobile can be a complicated, hydraulic-y thing full of spooky fluids and many spinning parts. However, simpler designs for “automatic” gearboxes exist, like this Lego design from [FUNTastyX].

The build is based around a simple open differential but configured in a unique way. A motor drives what would typically be one of the output shafts as an input. The same motor is also geared what would normally be the main differential input shaft as well. In these conditions, this double-drive arrangement would sum the speed input and lead to a faster rotational speed at the other shaft, which becomes the output.

However, the trick in this build is that the drive going to what would be the usual differential input is done through a Lego slipper clutch. This part, as explained by [TechnicBricks], allows the outer teeth of the gear to slip relative to the shaft once torque demand is exceeded. What this functionally does is that when the output of the “automatic gearbox” is loaded down, the extra torque demand causes the clutch to slip. This then leads to only one input to the differential doing any work, changing the gear ratio automatically.

It’s likely not a particularly efficient gearbox, as there are significant losses through the very simple clutch, we suspect. However, it does technically work, and we’d love to see its performance rated directly against other simple Lego gearbox designs.

It’s a little confusing to explain in text, but the video from [FUNTastyX] does a great job at explaining the principle in just a few minutes. We’ve seen plenty of crazy Lego gearboxes over the years, and we doubt this will be the last. Video after the break.

Continue reading “A Simple LEGO Automatic Transmission” →

Detecting Ripeness In Fruit And Vegetables Via Neural Networks

July 22, 2021 by 11 Comments

Humans have an innate knack for identifying food that is fit to eat. There’s a reason you instinctively enjoy fresh fruit and vegetables, but find maggot-infested rotting flesh offputting, for example. However, we like to automate as much of the food production process as possible so we can do other things, so it’s necessary to have machines sort the ripe and ready produce from the rest at times. [kutluhan_aktar] has found a way to do just that, using the power of neural networks.

The project’s goal is a straightforward one, aiming to detect ripeness in fruit and vegetables by monitoring pigment changes. Rather than use a camera, the project relies on data from an AS7341 visible light sensor, which is better suited to capturing accurate spectral data. This allows a better read of the actual light reflected by the fruit, as determined by the pigments in the skin which are directly related to ripeness.

Sample readings were taken from a series of fruit and vegetables over a period of several days, which allowed a database to be built up of the produce at various stages of ripeness. This was then used to create a TensorFlow model which can determine the ripeness of fruit held under the sensor with a reasonable degree of certainty.

The build is a great example of the use of advanced sensing in combination with neural networks. We suspect the results are far more accurate than could have reasonably be determined with a cheap webcam, though we’d love to see an in-depth comparison as such.

Believe it or not, it’s not the only fruit spectrometer we’ve featured in these hallowed pages. Video after the break.

Continue reading “Detecting Ripeness In Fruit And Vegetables Via Neural Networks” →

What Exactly Is A Gaussian Blur?

July 21, 2021 by 29 Comments

Blurring is a commonly used visual effect when digitally editing photos and videos. One of the most common blurs used in these fields is the Gaussian blur. You may have used this tool thousands of times without ever giving it greater thought. After all, it does a nice job and does indeed make things blurrier.

Of course, we often like to dig deeper here at Hackaday, so here’s our crash course on what’s going on when you run a Gaussian blur operation. Continue reading “What Exactly Is A Gaussian Blur?” →

DIY Fume Extractor Keeps Air Clean While You Solder

July 20, 2021 by 17 Comments

Soldering is a key skill to learn when building electronics, but it’s also a process that can put out a lot of fumes. The best way to deal with this is to use a fume extractor. Of course, you can always make your own, as [Open Green Energy] ably demonstrates. It’s a guided build of the design [rdmmkr] published on Thingiverse.

The build relies on a 120mm case fan for suction, and it’s combined with a activated carbon filter to best capture the harmful fumes from the soldering process. The fan is neatly installed inside a 3D printed enclosure of custom design, which also includes a removable tray which holds the filter material. The fan is run from a DC power supply via a barrel jack, and a basic speed controller is installed to allow the fan to be turned up higher for more suction, or lower to reduce noise.

It’s a useful item to have around the home workshop, and it’s something that you could easily whip up at home with parts from the junk bin if you’re so inclined. The benefit of 3D printing is that you can easily alter the design to suit whatever parts you have on hand.

We’ve seen a few fume extractor builds over the years, from the simple and basic to the very fancy. Video after the break.

Continue reading “DIY Fume Extractor Keeps Air Clean While You Solder” →

It’s Super Easy To Build Yourself A USB-C Variable Power Supply These Days

July 18, 2021 by 29 Comments

Once upon a time, building yourself a power supply required sourcing all manner of components, from transformers to transistors, knobs, and indicators. These days, everything’s a bit more integrated which helps if you’re trying to whip something up in a hurry. This build from [Ricardo] shows just how straightforward building a power supply can be.

The build is a simple mashup, starting with a ZY12PDN USB Power Delivery board. This board talks to a USB-C supply that is compatible with the Power Delivery standard, and tells it to deliver a certain voltage and current output. This is then used to supply power to a pre-built power supply module that handles current limiting, variable voltage output, and all that fancy stuff. It even comes with a screen built-in! Simply slap the two together in a 3D printed case with a couple of banana plugs, and you’re almost done.

All you need then is a USB-C power supply – [Ricardo] uses a portable power bank which allows him to use the power supply on the go. It’s a great alternative to a traditional heavy bench supply, and more than enough for a lot of hobby uses.

We’ve seen a lot of interest in USB Power Delivery recently, and its likely hackers will continue to enjoy the standard for some time to come. If you’ve got your own USB PD hack, be sure to let us know!

Arduino Cable Tracer Helps Diagnose Broken USB Cables

July 18, 2021 by 31 Comments

We’ve all found ourselves swimming amongst too many similar-looking USB cables over the years. Some have all the conductors and functionality, some are weird power-only oddballs, and some charge our phones quickly while others don’t. It’s a huge headache and one that [TechKiwiGadgets] hopes to solve with the Arduino Cable Tracer.

The tracer works with USB-A, Mini-USB, Micro-USB, and USB-C cables to determine whether connections are broken or not and also to identify wiring configurations. It’s built around the Arduino Mega 2560, which is ideal for providing a huge amount of GPIO pins that are perfect for such a purpose. Probing results are displayed upon the 2.8″ TFT LCD display that makes it easy to figure out which cables do what.

It’s a tidy build, and one that we could imagine would be very useful for getting a quick go/no-go status on any cables dug out of a junk box somewhere. Just remember to WIDLARIZE any bad cables you find so they never trouble you again. Video after the break.

Continue reading “Arduino Cable Tracer Helps Diagnose Broken USB Cables” →