in sw13 we would take a large assembly, save it as a part, then save as a step file, then we could e mail them. with sw17 its the opposite, if I save an assembly as a part or step it gets 3 times bigger. what the heck is going on here?
I've looked a bunch of places and couldn't find any information about any changes to how SW interacts with STP files. An exclusion being that 2017 offers MBD which can now work with STP242 - that's a different topic.
STP files with SW have always been buggy in my experience. Try Parasolids and zip or rar?
Perhaps something changed with the way that SW interacts with STP files because of new 3D Interconnect functionality.