🌀 Optical Illusion Desk Spinner (Floating Ball Effect)

A minimalist spinner that looks different when it moves

I wanted to make something that spins, but doesn’t need motors, wires, or batteries.

This project started with a simple question:

Can a spinning object make something look like it’s floating?

When this spinner is standing still, the ball clearly sits inside a twisted frame. Nothing special.

But when you spin it, something strange happens — the ball suddenly looks like it’s hovering perfectly in the center, disconnected from everything else.

There’s no magnet, no motor, no electronics. Just motion, balance, and how our eyes work.

What’s the Illusion Here?

The illusion only appears while the spinner is moving.

1. At rest → you can see the frame, the gaps, and the supports
2. While spinning → the frame visually disappears
3. Result → the ball looks stable and floating in mid-air

Your brain fills in the motion and ignores the structure.

The object doesn’t change. Your perception does.

Materials I Used

1. 1 × 608 ball bearing
2. (ceramic bearings spin longer and smoother, but steel works too)
3. About 70g of filament
4. Super glue (only if the fit is loose)

Tools

1. 3D printer
2. Slicer software
3. Sandpaper (optional)

Print Details

All parts were 3D printed.

Settings I used:

1. Layer height: 0.2 mm
2. Infill: 15–20%
3. Walls: 3 perimeters

Total print time was around 4 hours, and the full build used roughly 90 grams of filament.

Balance matters here, so cleaner prints give a better spin.

You can download the files from here...

The spinner rotates on a single 608 bearing.

1. Press the bearing into the center housing
2. It should be snug, not forced
3. If it’s loose, add a tiny drop of glue (avoid the inner ring)

A ceramic bearing isn’t required, but it really improves spin time — which makes the illusion stronger.

Assembly is simple:

1. Insert the bearing into the base
2. Attach the twisted frame
3. Place the ball in position
4. Secure the top part

Before calling it done:

1. spin it by hand
2. check for rubbing
3. make sure it spins freely and smoothly

Paste a small peice of double tape to fix the base on the table

This project only makes sense once it’s spinning.

1. Slow spin → you still see the frame
2. Faster spin → the frame disappears
3. The ball looks like it’s floating

If you hand it to someone without explaining anything, they usually stop and stare for a second — which is the best reaction.

Why This Works (Simple Explanation)

Our eyes don’t see fast motion frame-by-frame.

When the spinner rotates:

1. the structure moves too quickly to track
2. repeated motion blends together
3. the brain locks onto the ball instead

This is similar to:

1. persistence of vision toys
2. animation
3. optical illusion spinners

Things You Can Experiment With

1. Different ball sizes
2. Changing the twist angle
3. Matte vs glossy filament
4. Heavier or lighter base

Small changes can make the illusion stronger or weaker.

Final Thoughts

This build reminded me that you don’t need electronics to make something interesting.

A single bearing, a balanced shape, and motion are enough to create a moment where people genuinely question what they’re seeing.

If it makes someone spin it twice just to be sure — it’s working.