Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 35 replies
  • Subscribers 32 subscribers
  • Views 2373 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Choice of motor - application query

simonturner83
Hi

I am currently working on a design concept for a motion system - I would be very grateful for any advice that could be given on a suitable type of motor for the application (e.g. servo, stepper, DC motor etc.).
 The related requirements for the motion system are as follows:
  1. Rotate a cylindrical object placed on its side on friction rollers to allow inspection, where rotation occurs around the axial axis as per test tube rollers or pipe weld rollers.
    1. Details of the cylindrical object:
      1. It is unattached to the rollers, i.e. placed on for rotation / inspection then removed.

    2. Can weigh up to 20kg.



  • The cylindrical object is required to rotate at a very slow speed, typically 1rpm and lower, where the upper limit is likely to be in the region of 15rpm. The friction rollers on the motion system will be in the region of 1/10 to 1/20 of the circumference of the cylindrical object.

  • The rotation of the cylindrical object is required to be significantly consistent, i.e. smooth rotation with minimal stepping / juddering.

  • The motion  profile is likely to just be one full rotation of the cylindrical object at a fixed speed, but there may be a requirement to perform the rotation in increments with pauses in between (i.e. one full rotation split into 6x moves). The duty will be low, i.e. 5-10 such operations per day.

  • Allow some basic position/speed control, where closed-loop is preferable.

Many thanks.



Parents
  • 0
    So you want to turn something, slowly, smoothly,  and possibly steppily.

    How much torque, how much inertia, and how much accuracy do you need on the angular positioning ? You may need clutching or brakes if there is a requirement to come to a dead stop at a known angle from rapid motion.

    You are probably correct to think in terms of electricity as your preferred prime mover, but if you had said it was a missile and weighed tonnes I'd suggest you consider hydraulics with the oil controlled by solenoids.  I still might if the diameter is very large.

    Stepper motors are good for small controlled angles of rotation, as you can literally count the clicks, but be aware of starting and break-away torque limits, so you have a top speed limit and load limit to consider as well as a low starting torque

    You may servo any kind of motor on either shaft speed or angular position (and this can be very good - open a roller ball mouse to see how it can be done very precisely indeed) DC motors are easier to arrange if you have a wide speed range, for low speeds inverters and induction motors are probably not precise enough, some geared or belt driven reduction may well be needed.


    If it really is test tubes, then buy something from Festo or Rockwell, no need to design these days for any problem that has already been solved.
Reply
  • 0
    So you want to turn something, slowly, smoothly,  and possibly steppily.

    How much torque, how much inertia, and how much accuracy do you need on the angular positioning ? You may need clutching or brakes if there is a requirement to come to a dead stop at a known angle from rapid motion.

    You are probably correct to think in terms of electricity as your preferred prime mover, but if you had said it was a missile and weighed tonnes I'd suggest you consider hydraulics with the oil controlled by solenoids.  I still might if the diameter is very large.

    Stepper motors are good for small controlled angles of rotation, as you can literally count the clicks, but be aware of starting and break-away torque limits, so you have a top speed limit and load limit to consider as well as a low starting torque

    You may servo any kind of motor on either shaft speed or angular position (and this can be very good - open a roller ball mouse to see how it can be done very precisely indeed) DC motors are easier to arrange if you have a wide speed range, for low speeds inverters and induction motors are probably not precise enough, some geared or belt driven reduction may well be needed.


    If it really is test tubes, then buy something from Festo or Rockwell, no need to design these days for any problem that has already been solved.
Children
No Data

Community Rules & Guidelines