Ultimaker 2 Z-shaft endcap

Please note that I have not created these.

This bracket is used to keep the z-shaft rods in place.
I've converted them as a part of my Lets build an Ultimaker 2+ Extended clone project.

I just converted the STEP files from the Ultimaker 2 github repository to STL files.

Please let me know if I have broken some sort of license. (it is open-source, so I believe it is ok).