bottom portion 44 is flared outward to prevent the rubber band from slipping downward against the bar portion 42 the top and bottom flared portions 38 44 centers the rubber bands in the mid portion 46 to provide a desired alignment during assembly the edges of the flange 38 are rounded over to eliminate sharp edges or surfaces referring to fig1 a and 11a the example base 12 includes three rows of three cylinders 28 that are spaced equal distance from each other the tabs 32 and bosses 37 are received within corresponding slots 34 and 36 formed on the pin bar 14 a stabilizer 50 is disposed between each row of cylinders 28 to provide further lateral support for the pin bars 14 referring to fig1 b and 11b another example base 12 u2032 includes three rows of six cylinders 28 that are spaced an equal distance from each other the additional cylinders 28 provided by the larger example base 12 u2032 provide for mounting of additional pin bars 14 with the same number of bases 12 u2032 as appreciated it is within the contemplation of this disclosure to provide a base with any number of rows of and columns of cylinders 28 that provide varying mounting configurations for the pin bars.