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What does the inside of a bowling ball look like and why isn’t it just a sphere?

The bowling balls they are made with synthetic resins or urethane; they can have a maximum diameter of 21.8 centimeters and a maximum mass of 7.26 kg. Despite what we might think, they are not gods simple spheres with three finger holes: inside them there are not only layers of different materials but also weights of various shapes For optimize launches and the effects of trajectory, especially in the competitive world. To better understand how these objects are made, let’s analyze layer by layer how one is made professional ball.

Nucleus

The most important part of a bowling ball is its nucleus: it is a weight placed in its innermost part which is usually made in iron or calcium oxides. These weights can have different shapes, depending on of the effect that you want to impart to the ball during the throw: there are therefore both nuclei symmetrical That asymmetricaleach of which is capable of giving a particular effect to the ball. Champions are able to exploit the shape of the nuclei to their advantage, making throws with trajectories that, when seen like this, seem apparently impossible!

Image
Various forms of nucleus. Credit: User:Michael Barera/gallery/2019/April uploaded an original image file, of which the present file is a cropped version., CC BY–SA 4.0, via Wikimedia Commons

Filling

The nucleus is surrounded by a filling material rather light whose objective is ensure compliance between the core and the outer shell and also allowing the ball to maintain its shape with every launch. This material is chosen depending on the final weight you want to give to the ball and it goes from cork (now no longer in use) a polyurethane foams And resin matrices with glassy microbubbles.

External covering

The outermost layer it is the one that actually comes into contact with the track from bowling and, therefore, it is what determines the ball catching ability and his reaction with the track oil. There are for example coverings in plastic and in urethane, each of which allows you to make the ball’s movements more or less predictable.

Added to this is a second factor related to finishing the ball: the surfaces rougher increase friction, while those more smooth They have reduced friction, allowing the ball to slide down a longer stretch of lane. Once again, the choice of one type rather than the other depends not only on the characteristics of the track but also on the style of the player, who can customize his ball in every aspect.

The last aspect to consider is making the finger holes. In the case of professional balls the length and the distance among these it is precisely calibrated to the size of the athlete’s hand. But not only that! Digging three holes could unbalance the ball, so upstream it is necessary to calculate how much mass will be removed in this phase, so as to calibrate the internal core accordingly.