Dual fan x-carriage

This is a X-carriage is for any 3D printer where the X axis is horizontal and the distance between the two linear shaft center is 50mm. For extruder pusher, please refer to thing:39933: http://www.thingiverse.com/thing:39933 For the full setup, please refer to this detailed article/howto: http://blog.arcol.hu/?p=1991 -- This is a thing:15534 minor fix, I adjusted the holes, and nuts size. The license is the same as the ancestor.