The 5-Star Standard Hub Connector is an integral component for all Sonostar standard domes. There are 6 of the 5-star hubs used in every dome, and 12 used in a sphere. Sonostar 5-Star hubs are designed to be used with 1/2" Schedule 40 PVC tubing. Please note that there is no 1/2" dimension on these hubs. If you need spares, or have a project that requires standard 5-star connectors, this one's for you. Sonostar's unique connectors are designed to fit 1/2" Schedule 40 PVC pipe, and come with molded holes 1/2" from the end of each arm.
The hubs are made of high-strength white PVC, with pre-molded holes for bolt fasteners placed 1/2" from the end of each arm. There is a 10-degree curvature molded into each arm from the hub center, which gives the hubs an 'inside' and an 'outside' when putting the dome together.
PVC pipe is measured by the inside diameter of the pipe so that the volume of air or liquid can be measured. The inside diameter of the Sonostar hubs corresponds to the outside diameter of the pipe so that the pipe can fit snugly inside the hub arms. The actual inside diameter of standard Sonostar hubs is .84 of an inch.
Each arm has exactly one inch of sleeve room for the inserted pipe. You have the option of either gluing the pipes into the hubs or securing them with nuts and bolts. Stainless Steel nuts and bolts are included in both the Basic Kits and the Full Kits.