Need Help! Limit and home switches not working


Results 1 to 2 of 2

Thread: Limit and home switches not working

  1. #1
    Member
    Join Date
    Aug 2016
    Location
    United Kingdom
    Posts
    26
    Downloads
    0
    Uploads
    0

    Default Limit and home switches not working

    I had my machine set-up with a DB25-1205 BOB running a 240V woodworking router and all was well except an occassional error with the z-axis limit switch.
    I decided to change to a 3 phase motor driving it through a "MACH 3" board. Because of the transient problem on the z axis i ran screened cables to the limit switches.
    Having got the motors on the three axes working i went on to add the safety circuits and started with the x-axis.
    I have tried many combinations of setting in stepconf all to no avail.
    The first image below shows the Mach3 board and its wiring. Pin 13 is allocated to the x-axis microswitch and returns to the GND terminal.
    The stepconf set up is shown on the second image.
    Measured reistances and voltages between 13 and GND are:-
    With no power resistance = 1.9ohms (I'm using fine signal wire and this is it's resistance).
    With power on and the micro-switch closed circuit the voltage is 0V
    With power on and the micro-switch open circuit the voltage is 16.3V
    Pin 12, for example, with no wires connected and not allocated in stepconf gives 9.6V
    In this configuration i get an error message when i try to switch on Linux, "Joint 0 on limit switch error". If i invert the stepconf setting for Pin 13 then the machine will run but when trying to home the x axis the switch is inoperative.
    I've fed the board with 5V from an external source and both with and without the USB cable.
    Any help would be appreciated in allowing me to set up the limits and home.

    Similar Threads:
    Attached Thumbnails Attached Thumbnails Limit and home switches not working-limits-2-jpg   Limit and home switches not working-limits-3-jpg  


  2. #2
    Member
    Join Date
    Aug 2016
    Location
    United Kingdom
    Posts
    26
    Downloads
    0
    Uploads
    0

    Default Re: Limit and home switches not working

    Posed same question on LinuxCNC site and got good lead.
    I had to change the parallel cable, due to gender change on BOB, and the new cable was not fully populated.
    Changed cable and all goes well.



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

Limit and home switches not working

Limit and home switches not working

Limit and home switches not working