This paper presents the Spherical Microphone Arrays Little Library (SMALL) 1. The latter consists of an opensource set of Computer Aided Designs to easily build Spherical Microphone Arrays prototype for research or home use. The designs are made with opensCAD, they are customizable and the different parts can be directly 3D printed. Extra standard mechanical assembly elements may be required such as screws or metal rods. Two main configurations are proposed: open sphere or rigid sphere. The customization parameters are the array radius, the number and position of the microphones with a set of predefined configuration, their type and extra options such as the possibility to embed an USB sound card inside the array. The microphone arrays signal processing for a Spherical Harmonic decomposition is provided as a code in the Faust language. Also, Python codes are provided for the calibration of the Spherical Microphone Arrays using a robotic arm. Preliminary measurements of the decomposition onto Spherical Harmonics are carried out for a 2 nd order prototype.