In my building gantry router cnc machine, 3 axis are through the timing belt drive connections to the ballscrews. No solid solution to the little non-synchronization between gantry drives or backlash are there then. May be the using of glass scale encoder is a solution. But it cannot be implemented in Mach3 environment under servo or stepper motor drive conditions. Presently, no step down gear ratio are used between the timing belt pulleys(Is it better than using small pinion to a large gear in term of backlash amount??). Two 32 teeth are linked with MT5 belt. Wider belt is more preferable in that case as well. Thanks.