S3D has a problem generating way more line segments that is sane/reasonable, and Smoothie can choke on that.
Issue discussion here… http://smoothieware.org/forum/t-1179593?from=email#post-2284378
Cleaning up gcode
There are a number of cleanup postprocessors for the S3D gcode that fixes the issues…
https://groups.google.com/d/topic/smoothieware-support/TKtdYDK2_fY/discussion
And an online version : simply pass your S3D gcode through this tool and the problem will stop occuring :
