FlipSpin - Self-Flipping Spinning Top

FlipSpin

This model is a self-flipping spinning top with an optional ripcord launcher.

The top can be started normally by hand, just like a classic spinning top. The additional launcher is mainly designed as an easy-start aid for users who find it difficult to give the top enough spin by hand, for example children or people with limited finger strength.

The launcher uses a simple toothed ripcord mechanism: the top is placed into the holder, the ripcord is inserted, and then pulled quickly. This transfers the pulling motion into rotation and gives the top a stronger, more consistent start.

And yes, the launcher may remind you of a certain childhood toy where everyone dramatically pulled a ripcord and expected a full-scale battle in the living room. This model is a small 3D-printable nod to that feeling — but instead of fighting another top, it fights gravity, flips itself over, and keeps spinning on its head.

What Makes It Special

Unlike a normal spinning top, this one does not just spin in one position. It starts on its rounded body, gradually leans over, flips itself upside down, and continues spinning on the small stem. The self-flipping motion is the main feature of the model and makes it much more interesting to watch.

The Physics Behind It

When the top is not spinning, it behaves a bit like a roly-poly toy: its center of mass is positioned so that gravity naturally brings it back into the upright position with the stem pointing upward.

Once the top starts spinning, gravity, friction, and rotation interact in a more complex way. The top does not rotate around one fixed point. Instead, it rolls along a small contact path on its rounded body. Because the rotation axis and the symmetry axis are slightly offset, friction creates an additional torque.

This torque gradually makes the top lean further until it flips over. After the flip, the top continues spinning on its small stem. The rotation direction stays the same from an outside perspective, but energy is lost through friction and because the center of mass is lifted during the flip, so the spinning speed decreases over time.

This makes the model a compact demonstration of center of mass, torque, friction, precession, and rotational motion.