MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
You are missing the hole in the hub for the pin that attaches the hub to the caster block. Other wise you only have one point of contact and it will not hold the skis stable when turning. Here is a picture of a similar hub with an exploded view of the hub and caster block