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 aware that the top of the lead screw is supposed to be free?
If it was fixed at the top, then it would not make much sense to have a flexible coupling at the bottom ;-)
Make sure that the motor shaft does not extend into the flexible part of the coupling.