3D Printed Straw Connectors V3

Another follow up to my original post about a 3D printed straw construction set, I've made a new shape of connector.  This new connector is shaped like a tetrahedral, it joins each straw at an angle of about 109.5 degrees to each other.  This shape is particularly interesting because it is commonly found in nature, most notably in molecules containing carbon.  In fact at the atomic level, diamonds (pure carbon) contain this same repeating tetrahedral configuration shown in figure 5.

I printed this connector with an epilog printer (the grand prize in the Make it Real Challenge!)  I've attached the AutoCAD and stl files below.