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Start by
Sudeep Patra
02-24-2014 08:44 PM

motion application... a servo or a stepper?

Which can be a better solution for any kind of motion application... a servo or a stepper... Accuracy is not a factor to consider
02-24-2014 11:11 PM
Top #2
Steen T. Falstrup
02-24-2014 11:11 PM
The servo solution will be the most profitable way to make motion-control. The step-motor requires additional hardware (and programming) to be operating in the same way.

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02-25-2014 02:06 AM
Top #3
Roozbeh Navadeh
02-25-2014 02:06 AM
except to its cost servo system is better
02-25-2014 04:35 AM
Top #4
Dave Emminger
02-25-2014 04:35 AM
it's really an apples to oranges comparison.Servo is closed loop, stepper is generally open loop control. There are differing applications where each is the better fit.
02-25-2014 06:43 AM
Top #5
Balakrishna Padiyar
02-25-2014 06:43 AM
One has to look what you want achieve,servo control is definitely better for precision control and for auto mode operation hooked up with real time process control .
02-25-2014 09:32 AM
Top #6
Dwight McCormick
02-25-2014 09:32 AM
The stepper could be a much cheaper solution if it accomplishes the results you desire. A simple step and direction controller is much cheaper than a servo controller. Many high speed counter cards have a step and direction output that you can user to control the stepper controller. As the name implies the stepper motor moves in discrete steps, you can also step it half and quarter steps. The stepper motor is OK if you do not need high torque and do not need to control the torque. Stepper motors tend to run hotter than servo motors as the amount of current the motor consumes is not dependent upon the load. Some controllers will let you reduce the current between steps, this would be OK if you do not need as much torque to hold position as to step to position.
02-25-2014 12:10 PM
Top #7
Ralph Koettlitz
02-25-2014 12:10 PM
Steppers allow as well as servo motors closed loop solutions like those from http://www.trinamic.com/ . Steppers are much cheaper but doesn't have that much torque expecially at higher speeds. Which type of of motor someones wants to use depends on the problem to solve.
02-25-2014 02:40 PM
Top #8
satish mishra
02-25-2014 02:40 PM
If accuracy doesn't matter then it is better to choose stepper cause it will be economically better.
02-25-2014 05:11 PM
Top #9
Ahmed Almoutaz
02-25-2014 05:11 PM
02-25-2014 07:21 PM
Top #10
Rajesh Maheshwari
02-25-2014 07:21 PM
If properly sized, a stepper motor solution is cheaper and robust--less complicated than a servo.

The above assumes point to point motion--i.e. no velocity profiles needed. Along with, if accuracy is not a concern, why not use DC motor instead? If you need high starting torque use a series wound DC motor. Use limit switches to shut the motor at end of motion--simple digital circuit will enable reverse motion. In the end, the choice of the drive system ultimately depend on the motion profile and the load.
02-25-2014 10:07 PM
Top #11
Andrea Dalla Giustina
02-25-2014 10:07 PM
Hi I'm andrea from Italy
Sorry fo my "little english".
I'm using stepper motor in closed loop (actually with an incremental encoder). With this solution there is not the step loss problem, there is not temperature problem because the current is not fixed but it's modulates and the system is chipper than brushless solution.
In my opinion the problem is the torque/velocity diagram of stepper motor. The torque decreases very fast when the velocity increases, but, in particular field of application (high torque and low speed) the stepper solution in closed loop is a good solution.
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