ESPboy Turned Into Functional Walkie-Talkie

June 27, 2023 by 17 Comments

The ESPBoy was first built as a hackable open-source game engine and handheld console for educational purposes. However, it’s also a platform that can readily support all kinds of other uses. You can even turn the humble handheld device into a working walkie talkie.

The build relies on adding a SA868 transceiver module to the ESPBoy, along with a microphone, speaker, audio amplifier and antenna as supporting hardware. It then relies on the ESPBoy’s existing screen and buttons as a user interface for the radio. Assembled appropriately, it can then be used as a very basic and barebones walkie talkie for voice communication.

You won’t get coded squelch or other useful features, but it’s enough to let you talk over the air with other handheld radio users. The SA868 module can transmit on a variety of frequency bands, but the video shows it operating in the UHF band around 433 MHz. With a power on the order of 1.8W, it should get you a few kilometers of transmission range in an open field.

Check out our earlier coverage of the ESPBoy and its many different configurations. Video after the break.

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Luxury Train Cars Used To Ride On Paper Wheels

June 27, 2023 by 20 Comments

Early on, railways primarily used wheels made of wood or iron. The former were cheap and relatively easy to manufacture, while the latter had far superior wear qualities. It may surprise you to learn, however, that some railways once used wheels made out of paper, as [Train of Thought] explains.

The wheels were pioneered by a man known as Richard N. Allen, in the 19th century. The wheels were constructed by layering up hundreds of sheets of paper with glue, compacting them with a press, and allowing them to cure for a few weeks. The solid paper disks were then machined to size, and were drilled to accept bolts that attached metal plates for protection. The wheels were given a cast-iron hub and a steel rim for wear reasons.

The benefit of the wheels was that their composite paper construction helped damp vibrations and noise from the wheels and rails. The North American Pullman railway ended up using the wheels for sleeper and dining carriages for the more luxurious ride they provided.

The paper wheels were short lived, however. While the wheels were up to the task when new, they would fail much sooner than solid metal wheels. A series of derailments led to the wheels being declared unsafe for use in the US by 1915.

The wheels serve as a good example of wheels and tires acting as a tuned part of a whole suspension system. Experimental wheel designs come and go, but there are reasons why we landed on certain designs for certain applications, after all. Video after the break.

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Podcast Feedback: Be Careful What You Ask For

June 27, 2023 by 18 Comments

I had one of those experiences yesterday that seem so common these days: the arrival of a mystery Amazon package. You know the kind — you get a shipping notice from UPS with the faux-excited “Your package is arriving today!” message, but you’re sure you haven’t ordered anything in a while. You check your Amazon order history, find nothing pending, and puzzle over who could be sending you a package. What could it be? A gift from a secret admirer, perhaps?

And so it was with me as I waited for the UPS driver to make her rounds of our neighborhood and drop the package off on our front steps. Surprised at its size, I hurriedly brought it inside, zipped open the box, and pulled away the packing to reveal…

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An Android Phone Powers A Self Driving Car

June 27, 2023 by 31 Comments

As auto manufacturers have brought self-driving features to their products, we’re told about how impressive their technologies are and just how much computing power is on board to make it happen. Thus it surprised us (and it might also surprise you too) that some level of self-driving can be performed by an Android phone. [Mankaran Singh] has the full details.

It starts with the realization that a modern smartphone contains the necessary sensors to  perform basic self-driving, and then moves on to making a version of openpilot that can run on more than the few supported phones. It’s not the driver-less car of science fiction but one which performs what we think is SAE level 2 self driving, which is cruise control, lane centering, and collision warning. They take it out on the road in a little Suzuki on a busy Indian dual carriageway in the rain, and while we perhaps place more trust in meat-based driving, it does seem to perform fairly well

Self driving features are codified into a set of levels for an easy reference on what each is capable of doing. We’ve taken a look at it in the past, should you be interested.

Wind-to-Heat: A Lot Of Hot Air?

June 27, 2023 by 85 Comments

Heating is one of the greatest uses of energy in human society today. Where we once burned logs to stave off the brutal winter chill, now we lean on gas and electricity to warm our homes and keep us safe and toasty. In some colder climates, like the UK, heating can make up 60-80% of total domestic energy demands.

However, there are alternative ways to provide heating. Using wind energy to directly provide heat could be key in this area, using a variety of interesting methods that could have some unique niche applications.

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Spindle Upgrade Makes PocketNC Faster And Smoother

June 27, 2023 by 21 Comments

Conventional wisdom says that rigidity is the name of the game when it comes to machine tool performance. After all, there’s got to be a reason for CNC machines that need specialized rigging companies just to deliver them. But is there perhaps a way for the hobby machinist to cheat a little on that?

From the look of [Ryan]’s PocketNC spindle upgrade, it seems like the answer just might be yes. The PocketNC, a much-coveted five-axis CNC mill sized for the home shop, has a lot going for it, but as with most things, there are trade-offs. Chief among these is a lack of the usual huge, heavy castings used for CNC machines, which results in the tendency for the cutting tool to chatter or even stall out if you push the speeds and feeds too far. After a good intro to some of the important metrics of machining, such as “material removal rate,” the video below delves into how MRR affects chip load which in turn results in chatter.

The easy fix for chatter, of course, is to take smaller cuts. But [Ryan] decided to increase the spindle speed to take lighter cuts, but to do it really fast. The hardware for this includes a 3,500 KV high-torque brushless DC motor and a custom spindle attachment. The motor is connected to the spindle shaft using pulleys and a drive belt, and the shaft is supported with stout bearings that can be pre-loaded to fight backlash. The end result is three times the stock 10,000 RPM spindle speed, which lets [Ryan] see a 300% increase in cycle time on his PocketNC. And as a bonus, the whole thing requires no permanent modification to the machine and can be easily removed.

We think [Ryan] did a great job breaking this problem down to the essentials and hacking up a low-cost solution to the problem. Continue reading “Spindle Upgrade Makes PocketNC Faster And Smoother” →

Escalate The NERF Arms Race With Self-Firing Missiles

June 27, 2023 by 2 Comments

NERF guns are a toy that appeals to adults and youngsters alike — if you’ve never had the chance to pelt your friends with safe and kid friendly foam darts in a surprise ambush, you haven’t lived. But just as with real-world weapons of the type superpowers put in shows of military strength, there’s an arms race in the world of NERF. Mere darts aren’t enough, and there’s a range of missiles for the bellicose youngster intent on skirting the brink of global foam dart annihilation. These come with a catch though in the shape of a lackluster launcher, and this has prompted [Joel Creates] to create a self-firing NERF missile with a secondary rocket motor.

A supercapacitor stores enough energy to light a small scrap of guncotton explosive when sent through a heater coil, and this should be enough to launch the missile. Perhaps this whole video should sit in “Don’t try this at home kids” territory, but try he does, with multiple dead ends along the way. The final try is a secondary rocket motor inside the missile that’s triggered by a micro switch upon leaving the standard NERF launcher. It’s not a resounding success, but we’re sure you’ll agree it’s an entertaining video to get there.

We’ve featured quite a few NERF hacks over the years, including this large auto-aimer.

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