5.5

3-D print this part on its own or along with the other components in the [Maker Studio Gears Set](http://amzn.to/1CtP2qF) the [Maker Studio Winches Set](http://amzn.to/1ykEoNR) and the [Maker Studio Propeller Set](http://amzn.to/1OFnS5j). STL and PDF files are available on thingiverse or you can buy the sets in your local toy store.