HyperCube (and Evo) Leg Extension - Supported

This is a remix to allow better support of the leg extension. It has an optional M8 screw that can be used to secure it to the extrusion once tapped. It is very strong with no no wobble. Because the hole for the M8 screw was added the optional nut for an anti skid pad was removed. A stick on anti skid pad (if desired) would need to be used.