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.
Hope you don't mind - I've taken your flow restricter idea and made it into a tube connector with a 2.5mm ID. I've added it as a remix here - Flow restrictor, and credited you with the original idea.
It's working well on my fountain which is cycling around once every 7 seconds. It's easy to change the internal diameter in something like tinker cad if you want to try different sizes.