TinyG limit switch reaction time

Home › Forums › TinyG › TinyG Support › TinyG limit switch reaction time

Tagged: 

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • April 15, 2013 at 3:51 pm #4007
    Karl Lew
    Member

    My TinyG is happily wired in to FirePick and is humming along quite nicely:

    http://www.youtube.com/watch?v=eWZ145UbPq8

    I have a question about limit switch reaction time. As you can see in the homing video, the drive belt whips and slackens when the head contacts the limit switch at the homing velocity, which is 1/30 of the maximum velocity. If I increase the homing velocity, the head derails off the MakerSlide because it’s basically crashing into the limit switch.

    I have NO limit switches. If I switch to NC limit switches, will I see improved reaction time from TinyG since it may not need to debounce as long?

    April 16, 2013 at 1:40 am #4009
    Karl Lew
    Member

    Alden, thank you for your most excellent advice. It was indeed the jerk homing parameter:
    http://youtu.be/QYS0nsMFFH0
    The jerk homing is now set at 64x jerk maximum, which makes TinyG “react faster” to prevent head crash into homing stop. Doing this also permitted faster search velocity.

    April 17, 2013 at 10:01 pm #4018
    Riley
    Keymaster

    Just to be clear Alden, on the OpenPNP forum posted this response.  Thanks for the follow up Karl.  You rock.

     

    It’s expected that the search velocity needs to be tuned for the setup, and should be significantly slower than the max velocity. Have you tried using a higher jerk for homing? The homing jerk is independently settable for this purpose. The jerk can actually be set high enough that you lose steps on the decel. This is OK as you are in a homing operation. You would never want to run it this high in actual operation. Please let me know if this gives you more headroom.

    Alden
  • Author
    Posts
Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.