MagicBox – The Color-Changing Ball Illusion

"Is it magic, or is it smart engineering?"

Spark curiosity and amazement with the MagicBox, a 3D-printable magic box designed to instantly transform the color of a ball right before your eyes!

Place the red ball into the socket, slide the drawer fully inside the outer sleeve, and pull it back out: the ball has magically turned yellow! It is a classic, captivating illusion trick created to delight kids, families, and anyone who loves clever hidden mechanisms.

✨ How It Works

The model relies entirely on a clever mechanical sliding mechanism hidden inside the structure. When the drawer is fully inserted into the outer case, internal geometry triggers a smooth swap of the sphere—no electronics or external tools required.

Video: https://youtube.com/shorts/Mt3V2U-_Udw?si=hJUmV0rMiQNM3VPj

🖨 Print Settings

The model has been carefully optimized for an easy and clean printing experience:

• Supports: ❌ NO supports needed (all parts are designed to print flat on the build plate).
• Layer Height: 0.16 mm or 0.20 mm recommended for smooth sliding surfaces.
• Perimeters/Walls: At least 3-4 perimeters to ensure full opacity so light doesn't reveal the internal trick.
• Infill: 15% - 20% (Gyroid or Grid).
• Recommended Material: PLA or PETG.

🧩 Assembly & Tolerances

The model consists of several separate 3D-printed parts designed to snap together.

⚠ Important Note on Tolerances:

To keep the illusion seamless and prevent the internal mechanism from binding, the sliding and snap-fit tolerances are fairly tight.

• Make sure your 3D printer is well-calibrated (especially your Flow Rate / Extrusion Multiplier).
• If any joint feels too tight due to elephant's foot or tiny blobs, a quick touch-up with fine sandpaper (400 grit) will make everything slide smoothly.

🎁 What You Need for the Trick:

1. Printed MagicBox parts (Outer sleeve and inner drawer).
2. Two identical-sized balls in different colors (e.g., Red and Yellow).

If you enjoyed this design, please leave a Like, share a Make showing off your color swap, and happy printing! 🏆