Building the Most Simple Motor in Mostly LEGO

Although [Jamie’s Brick Jams] has made many far more complicated motor design in the past, it’s nice to go back to the basics and make a motor that uses as few parts as possible. This particular design starts off with a driver coil and a magnetic rotor that uses two neodymium magnets. By balancing these magnets on both sides of an axis just right it should spin smoothly.
The circuit for the simple motor. (Credit: Jamie’s Brick Jams, YouTube)
First this driver coil is energized with a 9 V battery to confirm that it does in fact spin when briefly applying power, though this means that you need to constantly apply pulses of power to make it keep spinning. To this end a second coil is added, which senses when a magnet passes by.

This sense coil is connected to a small circuit containing a TIP31C NPN power transistor and a LED. While the transistor is probably overkill here, it’ll definitely work. The circuit is shown in the image, with the transistor pins from left to right being Base-Collector-Emitter. This means that the sensor coil being triggered by a passing magnet turns the transistor on for a brief moment, which sends a surge of power through the driver coil, thus pushing the rotor in a typical kicker configuration.

Obviously, the polarity matters here, so switching the leads of one of the coils may be needed if it doesn’t want to spin. The LED is technically optional as well, but it provides an indicator of activity. From this basic design a larger LEGO motor is also built that contains many more magnets in a disc along with two circular coils, but even the first version turns out to be more than powerful enough to drive a little car around.

youtube.com/embed/sX7x0XwtlKQ?…

hackaday.com/2026/02/14/buildi…

🚀 60 anni e non sentirli… più o meno 😄

🧭 Prologo

Ne ho passate tante, di tutti i tipi e in tutti i campi.

Per 30 anni ho lavorato come esperto e supporto dati e sistemi in una grande azienda di telecomunicazioni… finché un bel giorno è arrivata la diagnosi, tumore alla testa.

Mi davano per spacciato, o nella migliore delle ipotesi paralizzato a vita.
È andata diversamente, e sì, mi è andata benissimo.

Oggi sono su una sedia a rotelle, ma con una cosa che non mi hanno tolto, la forza d’animo.

🎂 Tris di festeggiamenti

• 12, compleanno di snowfan.it
• 13, il mio 60°
• oggi, San Valentino… e stasera festeggio al mio club di motociclisti 🏍️❤️

Sì, tutto sommato… sono felice.

🛠️ Rinascita, versione Linux

In questi 8 anni da quel giorno fatidico dell’operazione, ho ripreso a studiare e smanettare forte con
Linux, server e Fediverso.

Il lavoro di prima mi ha dato basi solide, ok.
Ma adesso ho una cosa rarissima… tempo, e posso usarlo senza padroni.

🖥️ La mia piccola flotta

Attualmente, 3 server

• 2 VPS
• 1 VDS

e ci tengo su un bel po’ di roba che amo curare
Mastodon, Pixelfed, Matrix, SearXNG… e l’ultimo arrivato, SNAC2 ✨

🧪 Routine da vecchio guerriero

Leggo log ogni giorno.
Provo, cambio, sperimento… e ti dirò, lavoro più adesso in pensione forzata che quando lavoravo “sul serio”.

Il motivo è semplice
mi piace, adoro il Fediverso, e mi sento di nuovo utile a qualcuno.

🧟 Epilogo, addio zombificazione

Anni fa stavo sui social “classici” come uno zombi, senza sapere bene nemmeno perché.

Adesso invece mi dedico a qualcosa di utile per una comunità, piccola o grande che sia, e soprattutto con una differenza enorme
so come funziona, so cosa sto facendo, e so perché lo faccio.

🌌 Fine del pippone

I miei primi 60 anni sono stati intensi.
Chissà come saranno i prossimi…

Io intanto, una cosa l’ho già scelta
continuo a costruire. 🔧🌿

Rock Sphere Machine Produces Off the Charts Satisfaction

[Michigan Rocks] says he avoided making rock spheres for a long time on account of the time and cost he imagined was involved. Well, all that is in the past in light of the fabulous results from his self-built Rock Sphere Machine! Turns out that it’s neither costly to make such a machine, nor particularly time-consuming to create the spheres once things are dialed in. The video is a journey of the very first run of the machine, and it’s a great tour.
The resulting sphere? Super satisfying to hold and handle. The surface is beyond smooth, with an oil-like glossy shine that is utterly dry to the touch.
The basic concept — that of three cordless drills in tension — is adapted from existing designs, but the implementation is all his own. First a rough-cut rock is held between three diamond bits. The drills turn at 100 RPM while a simple water reservoir drips from above. After two hours, there’s a fair bit of slurry and the rock has definitely changed.

[Michigan Rocks] moves on to polishing, which uses the same setup but with progressively-finer grinding pads in place of the cutting bits. This part is also really clever, because the DIY polishing pads are great hacks in and of themselves. They’re made from little more than PVC pipe end caps with hex bolts as shafts. The end caps are filled with epoxy and topped with a slightly concave surface of hook-and-loop fastener. By doing this, he can cut up larger fuzzy-backed polishing pads and stick the pieces to his drill-mounted holders as needed, all the way down to 6000 grit. He shows everything about the pads at the 11:55 mark, and it’s an approach worth keeping in mind.

What is the end result like? See for yourself, but we think [Michigan Rocks] sums it up when he says “I wish you could feel this thing, it feels so smooth. It’s so satisfying to roll around in your hands. I’m so happy I made this machine. This is awesome.”

We’ve seen machines for making wooden spheres but this one makes fantastic use of repurposed stuff like inexpensive cordless drills, and the sort of wood structures anyone with access to hand tools can make.

youtube.com/embed/FSE1GE1mz2k?…

Thanks to [AloofPenny] for the tip.

hackaday.com/2026/02/13/rock-s…