http://tavmjong.free.fr/INKSCAPE/MANUAL_v14Draft/html/Tiles-Tricks.html

inkscape (works on Mac, PC, Linux) is a free open source vector drawing program. It has powerful and (to my mind) slightly non-intuitive commands for copying, rotating sets of objects.

• Make a shape
• Use the tile clone command
• set center of rotation where you want it (e.g. directly below the 1st object)
• make it have 1 row of N tiles (1 column)
• check the Exclude tile box.
• specify rotation amount in the rotation tab

create tiled clones

• Use the basic P1 simple translation tab

DXF is not good

Use Better DXF

http://www.bobcookdev.com/inkscape/inkscape-dxf.html

but first unlink the clones so they're all separate objects.