Closed loop Stepper holding torque enquiry


Results 1 to 6 of 6

Thread: Closed loop Stepper holding torque enquiry

  1. #1
    Member
    Join Date
    Feb 2013
    Location
    uk
    Posts
    81
    Downloads
    0
    Uploads
    0

    Default Closed loop Stepper holding torque enquiry

    Hi,

    I increasingly use a 4th axis in rotaty carving jobs. For a series of foam carving jobs i've made a lightweight 1 metre long trunnion to hold 200mm thick foam blocks to carve at 45 and 90 degrees degrees. The problem is its not got enough torque to hold itself in place at different indexed degrees when milling material.

    I bought 12nm stepper and HSC86 closed loop driver to run a 1:1 HTD belt and pulley. The stepper is standard 12nm 1.8 deg and the closed loop driver can go up to 110vdc and 70ac. Its currently ungeared (Gearing this would have been better granted but time and budget got in the way.) The trunnion bed is about 8kg set back 30cm from the axis rotation.

    As a 12nm stepper it should surely be able to hold better than it should. Without the obvious advantage of gearing where should I look first to improve its holding?

    Any thought or suggestions how to improve the mechanical, electrical or software setting most appreciated.

    Similar Threads:
    Last edited by marbles; 10-01-2020 at 02:52 PM.


  2. #2
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: Closed loop Stepper holding torque enquiry

    12Nm can only hold about 8 lbs 1 ft from the shaft. You have almost double the weight a little bit further away.
    Gearing is probably the only option.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  3. #3
    Member
    Join Date
    Feb 2013
    Location
    uk
    Posts
    81
    Downloads
    0
    Uploads
    0

    Default Re: Closed loop Stepper holding torque enquiry

    Hmm foot for thought. Yes gearing I know would help.

    I should have mentioned that I'm currently using a 48v supply, which is not helping matters. I would have thought a 100v supply would do a better job or am I looking at the problem the wrong way?

    Not having access to a harmonic drive or low backlash wormgear unit I suppose in terms of gearing I could increase the size of the Htd pulley on the stepper and decrease the pulley size on the shaft, that would assist I would have thought?

    Last edited by marbles; 10-01-2020 at 03:00 PM.


  4. #4
    Member CitizenOfDreams's Avatar
    Join Date
    Nov 2012
    Location
    USA
    Posts
    1267
    Downloads
    4
    Uploads
    0

    Default Re: Closed loop Stepper holding torque enquiry

    If the trunnion is indexed (as opposed to continuously turning), maybe a motor brake would help?



  5. #5
    Member
    Join Date
    Feb 2013
    Location
    uk
    Posts
    81
    Downloads
    0
    Uploads
    0

    Default Re: Closed loop Stepper holding torque enquiry

    Quote Originally Posted by CitizenOfDreams View Post
    If the trunnion is indexed (as opposed to continuously turning), maybe a motor brake would help?
    I have what I call a manual positioner already that has a couple of disks that I lock off with gclaps. Works great with a digital inclinometer to give me the exact angle. I do totally need to add a brake just not quite worked out how to add this electrically or in the code.



  6. #6
    Member
    Join Date
    Feb 2013
    Location
    uk
    Posts
    81
    Downloads
    0
    Uploads
    0

    Default Re: Closed loop Stepper holding torque enquiry

    Looks like as Gerry said some sort of gearing is the order of the day. I'll start the hunt for a low arcmin right angle planetary unit.

    As i'll need it for both index holding and continuous machining what would you suggest as a good gear ratio?



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Closed loop Stepper holding torque enquiry

Closed loop Stepper holding torque enquiry