I just realised the pics I posted were somewhat outdated. In the final version I moved the tabs holding rotating nuts/servos of X axis to the rear and turned them 180 degrees so the pulleys are just at the rear plane of gantry. This was done to make possible to add another pulleys so I can belt the two sides together with one long belt. There are schools of thought (especially on our local CNC forum) that they'd better be tied together so if one side will stall or not work properly the gantry won't damage the rails. I believe that this is not necessary as servos have quite reliable feedback and one stepper just wouldn't have enough torgue to damage rails and the other side will stall within few steps from the first side.