This is the Sci-Fi Lab B7, a kinetic sculpture where engineering meets imagination. This laboratory structure features a motor-driven marble system powered by a N20 motor (400 RPM recommended), which drives 4 synchronized conveyor belts lifting 8 mm steel marbles to the top. From there, the marbles descend through a network of spiraling rails winding around the lab’s core.

At the Front, a glowing blue lab tube radiates energy, while 14 interlocking gears transmit motion throughout the mechanism, creating a smooth flow. Building the B7 is a complex but deeply satisfying project — a mix of precision mechanics and sci-fi design that results in a functional marble run and a striking display piece.

• Designed for 8 mm steel marbles
• Powered by a standard N20 Motor from Maker's Supply
• 4 conveyor belts
• 14 interlocking gears for synchronized motion
• Optional LED lighting for the blue lab tube and windows

Bill of Materials

• 8 mm Stainless Steel Balls
• 6x Micro Steel Ball Bearings MR128
• N20 Reduction Gear Motor 400rpm
• 4 White 3030-LED Board
• Self-Locking Button Switch
• Power Distribution Board
• SH1.0 to SH1.0 Connector Adapter Board
• 4x M2x6 Screws

• 8x M2.5x6 Screws

   

Assembly Instructions

Tips:

• At every connection point of the rails, you can slightly rotate both rail ends to adjust the slope and fine-tune the marble movement.
• The gearbox axis has small dots that indicate where to attach the clamps, ensuring that the gears and the axis stay securely in place.
• Each rail is marked with a small letter to help with sorting — they start with A at the bottom and go up to T at the very top.

• If some rail connections at the building don’t hold tightly enough, apply a small amount of glue at the contact points to add extra stability.
• Every gear is numbered, making it easier to identify and position the correct one during assembly.

Assembly Guide Video:

Missing in the video:

• Before adding the Laser-object, add the small black Rail into the hole.
• At the end of assembly, add the black door with glue.

Troubleshooting

If the conveyor belt is too loose or sags too much, you have two options:

• Remove one conveyor belt link and try again.
• Use the alternative print profile with slightly shorter belts and test this version.

Have fun assembling! 🚀