Solidus Labs Dogleg GDR Delta 3d printer is interesting variation of RepRap Simpson. Information is limited, hopefully more will be available soon.
From video description:
Source:
http://www.youtube.com/channel/UCS9dnQROWtxe3Tqcf3pWnYQ?feature=watch
From video description:
First movements of our dogleg grounded delta robot(GDR) 3d printer. This is the first motion test using the delta marlin firmware on a gen 6 board controlled through printrun. The GDR idea is from the Simpson 3d printer but we utilize lead screw/worm gears for motion
Source:
http://www.youtube.com/channel/UCS9dnQROWtxe3Tqcf3pWnYQ?feature=watch