[aadityadengle]

yes bill i am using the scales just for feedback and ensure the axis position. the scales will provide actual travel or position to my software and on that basis the software logic will control the stepper motor.
I have done with the stepper controlling part in my project and now working on the feedback reading. the idea of using linear scales for the feedback is just exactly as you said. i want to minimize the backlashes and do my cnc a bit to the professional level.

[BillTodd]

My thoughts only but ...

Steppers either have enough power to get the job done, or they don't. If they are losing steps then adding extra ones seems a bit of a bodge (I suppose if speed is not important then slowing to ensure the extra steps actually do something might be OK - but then why not just go slow enough not to lose steps in the first place???)

On the other hand, if there is an inherent non-linearity in the stepper-motor drive mechanism then correcting by linear feedback would make some sense (although a similar effect could be achieved with a correction table)

In short steppers are good at low speed only their torque drops of at speed and there is no way to add extra 'oomph' when the going get tough.

So...

If you are going to the trouble of adding linear feedback , why not use a servo motor instead of a stepper?

Bill

[aadityadengle]

finally used US Digital QSB..... it rocks