Diagonal Boing Ball takes center stage in RobSmithDev’s latest Amiga tribute. To celebrate the 40th anniversary, Rob returns to his floating Boing Ball project. This time, he aims to fix a detail that has always bothered him: the ball’s spin. The original Amiga demo spins the ball at a slight diagonal, not a perfect vertical. Rob makes it his mission to match that effect and delivers a build that will fascinate Amiga fans and tinkerers alike.
Revisiting the Iconic Ball
Rob starts by comparing his previous floating Boing Ball to the classic Amiga demo. The demo’s ball spins on a diagonal axis, while Rob’s original model stayed upright. This subtle detail prompts a complete redesign. The new anniversary edition features not only the signature float but also that distinctive diagonal rotation, thanks to clever engineering inside.
Smart 3D Design and Construction
Rob takes viewers through the design process in Tinkercad, splitting the ball into two interlocking hemispheres. No glue is needed; teeth and grooves allow easy assembly and future access for tweaks. He prints a spherical ring to minimize support material and integrates aluminum rods for strength and non-magnetic properties. The internal structure houses a motor, a floating magnet, and a neat locking ring to keep the ball spinning at the right angle.
Engineering the Impossible
Achieving the diagonal spin is more than a party trick. Rob walks through a series of circuit experiments, searching for a way to power both LEDs and the motor from the same wireless coil system. He reverse engineers the LED board, tunes capacitor values, and even leverages resonance at 100kHz to eke out more power. After several tries and some clever hacks, Rob gets the motor spinning and the LEDs glowing together—without a tangle of extra components.
Assembly, Tweaks, and Final Results
The video showcases multiple attempts at the perfect print, using both opaque and transparent PLA for different lighting effects. Rob demonstrates handy tools and templates for cutting rods to size, ensuring the ball sits and spins just right. He also walks through assembly details for the base, which mimics the look of an Amiga A590 drive, right down to the touch sensor location.
The Mesmerizing Payoff
After all the experimentation, two finished Boing Balls take the stage. Both float and spin on their bases, mimicking that diagonal effect seen in the original Amiga demo. The sight of two balls, each influencing the other’s magnetic field, brings a lively and mesmerizing motion to the desk. Rob admits he still can’t choose his favorite finish, so he lets the viewers decide.
Try It Yourself
Rob wraps up by encouraging fans to build their own diagonal Boing Ball using the linked files and parts list in the video description. With step-by-step guidance and a printer capable of multiple colors, anyone can make their own tribute to 40 years of Amiga magic.
For the full experience and all the magnetic mayhem, don’t miss the video. Only the Amiga makes it possible!
