Weekend Workshop: Build an old-school lightbulb from pencil lead and a jar

By Rick Stella Published September 18, 2016

Need something to keep you busy this weekend? We’ve got you covered. The Weekend Workshop is our weekly column in which we showcase a badass DIY project that you can complete with minimal skills and expertise. We’ve dug through all the online tutorials and gone the extra mile to pinpoint projects that are equal parts easy, affordable, and fun. So put on your work pants, grab your tool belt, and head to the garage. It’s time to start building!

In the late 1800s, as Thomas Edison’s light bulb was sweeping the nation, electricity as a utility was widely cherished — and for good reason. Today, it’s just one part of an abundance of modern day utilities taken for granted. Having the ability to waltz into your local Home Depot and grab a LED light bulb off a shelf would be incomprehensible just 100 years ago.

So this weekend, instead of merely purchasing one, why not try to fashion your own light bulb out of a few ordinary items? Thanks to a sharp engineer on Instructables known as sathyanc, building your own electric light bulb shouldn’t take more than an hour. Using little else in terms of materials than a glass Mason jar, eight D-cell batteries, and a graphite pencil needle, this innovative light bulb is not only easy to build, but wildly novel.

To help you get started, we’ve sifted through sathyanc’s step-by-step walkthrough to find an exact build list for the project. Thankfully, they also posted a video detailing how to put together this DIY light bulb, so if reading isn’t your thing, you’re in luck. Here’s what you’ll need to get started:

Tools:

Alligator clips
Graphite pencil needle (0.5mm)
Cello tape

Materials:

Small support material
D batteries (8)
Glass Mason jar
Supply power adapter (optional if not using 8 D batteries)

With all the necessary tools and materials at the ready, it’s now time to start piecing together this homemade electric light bulb. Simply follow sathyanc’s comprehensive walkthrough and before you know it, you’ll be the proud owner of a DIY bulb that Edison himself would envy. Happy building!

Topics

Former Digital Trends Contributor

Rick became enamored with technology the moment his parents got him an original NES for Christmas in 1991. And as they say…

Cars

EVs top gas cars in German reliability report — but one weak spot won’t quit

future electric cars 2021 volkswagen id4 official 32

Electric vehicles are quietly crushing old stereotypes about being delicate or unreliable, and the data now backs it up in a big way. According to Germany’s ADAC — Europe’s largest roadside assistance provider — EVs are actually more reliable than their internal combustion engine (ICE) counterparts. And this isn’t just a small study — it’s based on a staggering 3.6 million breakdowns in 2024 alone.
For cars registered between 2020 and 2022, EVs averaged just 4.2 breakdowns per 1,000 vehicles, while ICE cars saw more than double that, at 10.4 per 1,000. Even with more EVs hitting the road, they only accounted for 1.2% of total breakdowns — a big win for the battery-powered crowd.
Among standout performers, some cars delivered exceptionally low breakdown rates. The Audi A4 clocked in at just 0.4 breakdowns per 1,000 vehicles for 2022 models, with Tesla’s Model 3 right behind at 0.5. The Volkswagen ID.4, another popular EV, also impressed with a rate of 1.0 – as did the Mitsubishi Eclipse Cross at 1.3. On the flip side, there were some major outliers: the Hyundai Ioniq 5 showed a surprisingly high 22.4 breakdowns per 1,000 vehicles for its 2022 models, while the hybrid Toyota RAV4 posted 18.4.
Interestingly, the most common issue for both EVs and ICE vehicles was exactly the same: the humble 12-volt battery. Despite all the futuristic tech in EVs, it’s this old-school component that causes 50% of all EV breakdowns, and 45% for gas-powered cars. Meanwhile, EVs shine in categories like engine management and electrical systems — areas where traditional engines are more complex and failure-prone.
But EVs aren’t completely flawless. They had a slightly higher rate of tire-related issues — 1.3 breakdowns per 1,000 vehicles compared to 0.9 for ICE cars. That could be due to their heavier weight and high torque, which can accelerate tire wear. Still, this trend is fading in newer EVs as tire tech and vehicle calibration improve.
Now, zooming out beyond Germany: a 2024 Consumer Reports study in the U.S. painted a different picture. It found that EVs, especially newer models, had more reliability issues than gas cars, citing tech glitches and inconsistent build quality. But it’s worth noting that the American data focused more on owner-reported problems, not just roadside breakdowns.
So, while the long-term story is still developing, especially for older EVs, Germany’s data suggests that when it comes to simply keeping you on the road, EVs are pulling ahead — quietly, efficiently, and with far fewer breakdowns than you might expect.

Cars

You can now lease a Hyundai EV on Amazon—and snag that $7,500 tax credit

amazon autos hyundai evs lease ioniq 6 n line seoul mobility show 2025 mk08

Amazon has changed how we shop for just about everything—from books to furniture to groceries. Now, it’s transforming the way we lease cars. Through Amazon Autos, you can now lease a brand-new Hyundai entirely online—and even better, you’ll qualify for the full $7,500 federal tax credit if you choose an electric model like the Ioniq 5, Ioniq 6, or Kona EV.
Here’s why that matters: As of January 2025, Hyundai’s EVs no longer qualify for the tax credit if you buy them outright, due to strict federal rules about battery sourcing and final assembly. But when you lease, the vehicle is technically owned by the leasing company (Hyundai Capital), which allows it to be classified as a “commercial vehicle” under U.S. tax law—making it eligible for the credit. That savings is typically passed on to you in the form of lower lease payments.
With Amazon’s new setup, you can browse Hyundai’s EV inventory, secure financing, trade in your current vehicle, and schedule a pickup—all without leaving the Amazon ecosystem.
It’s available in 68 markets across the U.S., and pricing is fully transparent—no hidden fees or haggling. While Hyundai is so far the only automaker fully participating, more are expected to join over time.
Pioneered by the likes of Tesla, purchasing or leasing vehicles online has been a growing trend since the Covid pandemic.
A 2024 study by iVendi found that 74% of car buyers expect to use some form of online process for their next purchase. In fact, 75% said online buying met or exceeded expectations, with convenience and access to information cited as top reasons. The 2024 EY Mobility Consumer Index echoed this trend, reporting that 25% of consumers now plan to buy their next vehicle online—up from 18% in 2021. Even among those who still prefer to finalize the purchase at a dealership, 87% use online tools for research beforehand.
Meanwhile, Deloitte’s 2025 Global Automotive Consumer Study reveals that while 86% of U.S. consumers still want to test-drive a vehicle in person, digital tools are now a critical part of the buying journey.
Bottom line? Amazon is making it easier than ever to lease an EV and claim that tax credit—without the dealership hassle. If you're ready to plug in, it might be time to add to cart.

Emerging Tech

Humanoid robots race against humans at unique half-marathon in China

A humanoid robot running in a half marathon.

You may have seen robots dancing like the music icon Mick Jagger, doing parkour, or even painting on a canvas. Tesla’s Optimus humanoid robot is eagerly anticipated, while Google and Meta are also planning to enter the field. The competition in the East, however, is on a different level altogether.

China just put humanoid robots to the test in the world’s first race of its kind, where they ran alongside humans in a half-marathon. A total of 21 robots lined up for the event in the Yizhuang half-marathon, following a long spell of supervised learning on roads.