Wombot threaded spool shaft

The spool shaft on the Wombot Exilis is good but it doesn't lock into place and i needed it to be a little wider.

I've included the blender file & openscad for remixing

I used this excellent set of code for openscad to generate the thread: http://dkprojects.net/openscad-threads/

If you print this with the flange side down for both parts, it wont need support material.