I designed this handheld gimbal as a demonstration for kids to learn how gimbals work. Gimbals have been used on sailing ships for centuries. They were used in the Inertial Measurement Units (IMU's) on the Apollo spacecraft to navigate to the Moon and back.
This is a "4 gimbal" design. The additional gimbal avoids "gimble lock" which would occasionally occur using a 3 gimbal design.
If you add a weight or something in the cup, you can move the handle in any direction you want and the cup will remain reasonably level. The faster you move it, the less stable it becomes but it will settle to a level state. Moving it somewhat slowly will yield the best demonstration.
Please post your comments and makes!
No Supports are needed. You can print this in place and all axis should move freely after printing.
I have tested this print at 100% and 75% scale. I tried 50% scale and although it worked, it didn't spin very nicely. I think if I broke in each axis for a while that it would work but it's pretty fragile at 50%. I'd recommend nothing smaller than 75% scale.