SOLVED Need Help setting home position on CoreXY machine.

  • Hello all!

    I am a bit confused setting up the home position for my printer. I am using the RepRapFirmware Configuration Tool to create my config files.

    Currently when I home the machine the X homes correctly and the Y moves in the opposite direction of the endstop, ideally I would like the X0, Y0 to be at the right/rear of the machine.

    My printer size is X=273 and Y=300 endstops are located X=high (left of machine) and Y=low (rear of machine).

    When I home X the printer the carriage moves to the left touches the endstop and sets the X position to X273. Therefore, if I send the carriage to X0 it moves to the right side of the machine. Which is correct.

    When I home Y the printer the carriage moves to the front of the machine (away from endstop) forcing me to stop the machine to avoid crashing with the front of the machine. The homing direction needs to move towards the low end or rear of the machine.

    Does this make sense? Seems the RepRapFirmware Configuration Tool is not creating the config for the Y endstop at the Low end correctly. I attached the config files.



  • Moderator

    So in order to preserve the right hand coordinate system so that parts come out correctly instead of mirrored, the 0,0 origin point must be in the front left corner of the printer when looking at it from the front. X+ moves to the right, X- moves to the left, Y+ moves to the back, Y- moves to the front. If you diverge from this arrangement, you'll constantly be fighting against the slicer in order to get parts that aren't mirrored in some way.

    Homing direction is seperate from this, and would be determined by the location of the endstops. You set the direction of movement in the homing files.

    I suggest you go through this documentation to determine first the correct motor direction, and then the correct homing direction.

  • @phaedrux


    While my other printers (not CoreXY) have the homing position and the 0,0 origin at the back/right of the printer...front left works for me too, kinda the same thing if you rotate the whole printer 180 degrees.

    Following the directions from the link that you gave me determined that my motors were swapped.

    Homing now positions the carriage at the rear/left or X0, Y300 which is where it needs to be for Home, sending the carriage to the origin at 0,0 places it at the Front / Left where it needs to be!

    Thanks for pointing me in the right direction and helping me sort this out.