1
\$\begingroup\$

I search for a stepper-, servo- or other motor and a related circuit, which is suitable to handle the following aspects:

  • freewheeling:
    Spinning the motor shaft by hand without (or as little as possible) friction

  • variable friction at the motor shaft under computational control: Rotate the motor shaft by hand with a specific rotation behavior (rotation needs less force (smoothly rotation), or rotation needs more force (hardly rotation))

  • motor brake / lock: Rotate the motor shaft by hand is not possible, position locked

  • exert a specific and directed motor force: Rotate the motor shaft with a maximum of force so that a human can not hold the shaft

I would be very pleased if anyone can give me any advice. It would be perfect if the motor size is as small as possible.

Thanks in Advance :-)

\$\endgroup\$
  • \$\begingroup\$ Any modern didgital PMSM servo drive system can do that, and much more. \$\endgroup\$ – Marko Buršič Sep 16 '15 at 13:33
  • \$\begingroup\$ Can you provide me a simple motor model with an example, tutorial-link? I find no suitable PMSM servo with a controller and example. \$\endgroup\$ – user3704293 Sep 17 '15 at 10:09
  • 1
    \$\begingroup\$ Industrial servo systems: Omron servo motor/drive, Yaskawa Servopack, Siemens S120, Beckhoff AX5xxx, Emmerson, Samsung,...If you like more accademic you have evaluation boards from TI, ST, Microchip, Freescale...probably is better to buy a used industrial one, cheaper. freewheeling - disabling the servo, motorbrake - set target position to actual position, exert - positioning/speed/torque control, force - torque control, or speed setpoint = 0 with low Kp gain. \$\endgroup\$ – Marko Buršič Sep 17 '15 at 10:23
1
\$\begingroup\$

I believe that the performance that you describe requires a servo motor with a high resolution shaft position feedback to a high quality controller. In order to select a torque rating, you need to quantify "force so that a human can not hold the shaft" and also define the maximum speed for shaft rotation under motor power. A servo motor system can hold a shaft at a fixed position quite well, but not as solidly locked as a friction brake.

\$\endgroup\$
  • \$\begingroup\$ Is there a way to use a servo in a non-positioning way and define a friction? As I pointed out at the second requirement, I need to control the motor shaft also manual by hand with different haptic feedback. And in my understanding servo motors are controlled by absolute positions. Can you provide me a simple example, tutorial-link or motor type on how to do that? Thank you so much :-) \$\endgroup\$ – user3704293 Sep 17 '15 at 9:24
  • 1
    \$\begingroup\$ I believe that a servo controller could be set up to hold the speed of the motor shaft at zero, but develop only a set torque to do that. That set torque could be adjustable from zero to the maximum capability of the motor. I can not provide any links. I suggest that you look for the web sites of the brands mentioned by Marko Buršič and download product literature and manuals. There is likely general tutorial information available, but I don't have any links to offer. \$\endgroup\$ – Charles Cowie Sep 17 '15 at 15:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.