Introduction: Marblevator, Spiral Disk.

About: Our grandkids keep me busy!

Marblevator, Spiral Disk is my simplest Marblevator yet! Requiring only two 3D printed parts, this Marblevator runs for hours without dropping a marble.

I designed the spiral disk (wheel) to run clockwise. With an 8mm ball bearing in the wheel track, as the wheel rotates clockwise, the ball bearing follows the spiraling wheel track until it reaches the end where a sloped surface ejects the ball bearing onto the base track. The ball bearing runs down the base track until it reaches the end where it waits until the wheel track start rotates into position, then falls back into the wheel track.

Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.1.0, and 3D printed in PLA on Ultimaker S5s.


  • Thick cyanoacrylate glue.
  • Soldering iron.
  • Solder.
  • Wire.

Step 1: Parts, Files and Assembly.

I acquired the following parts for this model:

  • One N20 100RPM gear motor.
  • Five 8mm ball bearings.

There are two 3D printed parts for this model, "Base.stl" and "Wheel.stl". I printed both of these parts at .1mm layer height, 20% infill, with no supports. However, even at .1mm layer height I still filed, trimmed and sanded both parts such that the ball bearings entered the track, rotated through the track, then exited the track with ease. Plenty of time and patience is required to perform this step.

The included video shows how to assemble the model. First, I soldered 80mm wires to the gear motor, then pressed the gear motor part way into the base. I next aligned the hole in the bottom of the wheel with the motor shaft, making certain the hole and motor shaft flats aligned, then pressed the wheel onto the motor shaft (If your wheel is loose on the motor shaft, a small dot of thick cyanoacrylate glue may be applied). With the wheel on the motor shaft, I slid the motor and wheel toward the front of the base such that it almost touched the base.

With the model assembled, I attached a 3VDC power source to the motor, made sure the wheel rotated clockwise as viewed from the front, added the ball bearings, and let it go! After an hour or so of successful operation, I added a small dot of thick cyanoacrylate glue between the motor and the base to hold the motor in position.

And that is how I 3D printed and assembled "Marblevator, Spiral Disk".

I hope you enjoyed it!