in need of a servo motor - slow working speeds

[atape]

Hi,

I am in need of a servo motor + controler that will run at really low speeds - 0.001 rpm. It needs to run smoothly, what kind of motor should I get, DC,AC? Manufacturer? It doesn't have to be all that powerful (about 120w, which is roughly 3nm in torque).

 

[tygerdawg]

try a stepper from

http://www.imshome.com

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[OperaHouse]

In particular look into a steper motor with a microsteping drive. These will turn a rotation into thousands of steps.

 

[cswilson]

You must be extremely careful in this type of application how you define "smoothly". Ultimately, whether you use a servo or a stepper motor, the best you will really be able to do is move from being at rest at one position increment to being at rest at the next position increment.

If you use a typical 200 step/rev stepper motor with a 256 microsteps per step drive, you will still need less than one increment per second at these speeds. When you look at the motion in the second timeframe, it will not be smooth. Over hours, it will be smooth. What do you really need?

Curt Wilson
Delta Tau Data Systems

 

[Clyde38]

More information is required. What is the duty cycle? What kind of power is available? AC, DC, or Brushless DC, all with the appropriate gearing may suit the application. A piezo motor may do the job.

[link

http://www.linkedin.com/in/clydehancock

]

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[Compositepro]

No mention has been made about upper speed required, or speed range.
Normally a gearbox is used on motors to get these very low speeds. Why is that not possible here?

 

[blacksea]

For such low power 120W DC brush motor can be well solution. But more important issue is position feedback sensor. It seems that you need in encoder with analog 1Vpp output for following interpolation by controller - see single axis digital controller with buil-in amplifier from Elmo or Copley for example.

 

[bib66]

Servo motors nearly almost have vibrations, which could make problems, when the velocity is so slow and the motor should run extremely smoothly.

Stepper motors do not vibrate and with microstepping there is the possibility to run the motors quite slowly. With 10.000 Increments per revolution the given velocity of 0,001 rpm means 10 Increments/minute.

Birgit Burdinski

http://www.xemo.de