Endstop detection



  • In marlin, the endstop connections, tell the motor to go the other direction, one the endstop is pressed, in the reprap firmware when i press 100 in x direction it tries to go of the rail by which point the end stop has been triggered,

    is there an issue with my files.

    Please help.

    When i home the axis and manually press the endstop, the endstop command terrminates the current comand and moves on to the next comand

    Kind Regards


  • administrators

    Endstop switches are normally active only during homing moves. These are G1 moves with the S1 parameter, which you will find in the homing files. So your comment "When i home the axis and manually press the endstop, the endstop command terrminates the current comand and moves on to the next comand" describes the expected behaviour.

    After the printer has been homed, the axis limits set by M208 are enforced to prevent the head trying to move outside the defined dimensions.

    Are you having a particular problem with homing?



  • i think im having issues addressing the general dimensions of the printer, I've got a printer with a x220 y220 z240, how would i define that ground zero is at the endstop location, and tell it to move from there.

    kind regards



  • Assuming your end stops are at the axes minima, then in your config.g you have :-

    M208 X0 Y0 Z0 S1 ; set axes minima
    M208 X220 Y220 Z240 S0 ; set axes maxima



  • @dc42:

    Endstop switches are normally active only during homing moves. These are G1 moves with the S1 parameter, which you will find in the homing files. So your comment "When i home the axis and manually press the endstop, the endstop command terrminates the current comand and moves on to the next comand" describes the expected behaviour.

    After the printer has been homed, the axis limits set by M208 are enforced to prevent the head trying to move outside the defined dimensions.

    Are you having a particular problem with homing?

    progress on the homing was working well once I made some changes to the maxima of the config.g file provided.

    when i home the y and the x axis, it reaches the endstops, retracts a little then touches the endstop again.

    with the z axis, I just purchased the http://www.ebay.co.uk/itm/5-X-PCS-Obstacle-Avoidance-IR-Sensor-Infrared-Module-Arduino-Raspberry-PI-/262723014158?hash=item3d2b830e0e:g:w3UAAOSwEzxYbjBn, so that the z homing works. and doesn't go throagh the bed


  • administrators

    @npm1:

    when i home the y and the x axis, it reaches the endstops, retracts a little then touches the endstop again.

    That's expected behaviour, it first homes quickly then it re-homes more slowly to get a more accurate homing position.

    @npm1:

    with the z axis, I just purchased the http://www.ebay.co.uk/itm/5-X-PCS-Obstacle-Avoidance-IR-Sensor-Infrared-Module-Arduino-Raspberry-PI-/262723014158?hash=item3d2b830e0e:g:w3UAAOSwEzxYbjBn, so that the z homing works. and doesn't go throagh the bed

    Be careful, you probably won't get a reproducible trigger height with that IR sensor.



  • @deckingman:

    Assuming your end stops are at the axes minima, then in your config.g you have :-

    M208 X0 Y0 Z0 S1 ; set axes minima
    M208 X220 Y220 Z240 S0 ; set axes maxima

    What does the S1 command do

    kind regards



  • @npm1:

    @deckingman:

    Assuming your end stops are at the axes minima, then in your config.g you have :-

    M208 X0 Y0 Z0 S1 ; set axes minima
    M208 X220 Y220 Z240 S0 ; set axes maxima

    What does the S1 command do

    kind regards

    S1 sets the minima, S0 or no S parameter will set the maxima. https://duet3d.com/wiki/G-code#M208:_Set_axis_max_travel


  • administrators

    The S1 parameter says that you are setting minimum coordinates. S0 or no S parameter says you are setting maximum coordinates. The minimum/maximum coordinates are also the ones assumed when a low/high-end endstop switch is triggered during a homing move.



  • Hia,

    Thanks for all the help, i have managed to get the printers homing working well on all axis,

    I just need to wait till the end stops and new ir probe comes, so that the printer works consistently,

    Would the the IR probe directly from duet3d work out of the box and to what kind of precision?

    kind regards,


  • administrators

    Please see https://miscsolutions.wordpress.com/mini-height-sensor-board/ for how to install and use the IR probe. The consistency of repeated probing at the same point is very high and typically limited by the resolution and reproducibility of your Z axis. The trigger height consistency across different areas of the bed depends on the bed surface - see the section on bed surface in the link above.



  • I have successfully moved forward with this, by telling the printer where 0 is i.e. 0 is at the endstop

    all so far is good


 

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