Abstract: A winder for winding and unwinding of materials, which utilizes a ball variator and planetary speed reducer in combination with a mechanism functioning as a regulator of speed output and tension desired for the materials. During a winding operation, the growing winding diameter of the material causes a rise in torque at the winding shaft and through a series of planet pinions, an increase of thrust at the ring gear of the planetary speed reducer. This increase of thrust is followed by rotation of the ring gear and control cam via a control lever. The rotation is transmitted from the control cam, through a clutch mounted on the control shaft and a series of gears to an iris plate of the ball variator and through the control shaft to a weight lever. The rotation of the iris plate causes a tilt of the balls of the variator, determining the drive ratio and output speed variation. The rotation of the weight lever causes tension desired for the material.