I used to use stepmotors for my designs so far but my new project requires servomotors . My new project will be a big router with the workable area of 3 m x 2 m and with the jogging speed of 1 m / sec . Probably I will use kremayer - pinion for the axis movements to achieve this speed .I will cut 18 mm MDF sheets for furniture industry. For optimum servo selection I was studying on data sheets of some motors. But I 'm confused a lot . I hope someone will help me to find optimum solution. At the beginning I have started with some considerations ; for example the cutting force will be 30 kg ,the jogging speed will be 1 m/sec . if I use 40 mm pinion I need 60 kg-cm( 6Nm) tork and I need 480 rpm at the output shaft of the motor ( or gear drive) . I thought if I use a servo without gear reduction very big motor must be used but I never use it at 3000 rpm where the eff. is high as 70 % and as the speed reduced the tork also reduces ( please see the data sheet) So I thought if I use a 5/1 reduction I will get 500 rpm at shaft when the motor at 2500 rpm and I will get very high tork with a small 1.5 Nm motor.This is the first step which I need your confirmation. Second step is the selection of the motors . In my opinion there is two kind of DC motors brushed and brushless . I think Brushless motors are better since they don't require maintenance . This is the second subject that I can not decide . For the drivers there is no big price difference between brushed and brushless drivers . I suppose I will get all the motors and drivers from here http://www.transmotec.com/ since the prices are very affordable.