The rotations of blue antenna of a worm gear (around two perpendicular axes XX and YY) are controlled by two grounded motors.
Yellow motor makes green frame rotate around axis XX thus controls the object rotation around axis XX.
Violet motor makes orange worm shaft rotate around axis XX thus controls the object rotation around axis YY.
Motion of the yellow motor also makes the object turn around axis YY a small value that is not easy to be realized. First part of the video shows this phenomenon.
To keep the object do not turn around axis YY while adjusting the object position around axis XX, the violet motor must rotate together with the yellow one (with different speed subject to transmission ratio of the worm drive). Second part of the video shows this correction.
Motion of the violet motor does not affect the object rotation around axis XX (see third part of the video).