Servos vs steppers and VFD articles

[wcarrothers1]

I'm a servo user. But figured anyone who wants to read a bit about servos vs steppers, Motion system Design Magazine (motionsystemdesign.com) has a good article in the Jan2011 ed.

Also the december ed had a good article explaining the in's and outs of VFD drives. (definitions of and such).. Both good reads.

b.

[RocketScientist]

I can explain from a control loop stability, analog noise vs digital noise (discretenes and bit drop-off). But, being a newbie here and no hands on with these devices when building CNC equipment, I am all ears here.

On the other hand, I could not tell you which would hold position better.. I hope someone here can share the hands on and practical tradeoffs between the two as I want to build a 5-axis CNC mill, a CNC Lathe and grinders. I have to start somewhere...

Thanks for letting me spill what I know.

Best - RocketScientists

[wcarrothers1]

Hmmm they both hold possition well, I think the big difference is if a open loop stepper gets bumped off possition it will not "know" to return where if I were to push my gantry so hard I could move it (against the servo already fighting me) it would move back to where it started after I was done pushing.

For the most part I don't think it's typical for a gantry to get bumped out of possition while standing still.

b.