About this 3D model

Use the M8 threaded rod and two nuts on the ends. Supports for nuts are parameterized - modify if you feel it necessary. UPDATE 19-09-2012: Parts slightly modified. Idler end fits F608 bearing. No bottom endstop - belt spreader instead. UPDATE 23-09-2012: Modified idler end. UPDATE 27-09-2012: Modified carrige.