Dual build volume explained (1.0 Dual)

Discussion in 'BigBox General Chat' started by Alex9779, Apr 10, 2016.

  1. Alex9779

    Alex9779 Moderator
    Staff Member

    Joined:
    Sep 4, 2015
    Messages:
    2,405
    Likes Received:
    731
    In my S3D profile explanation I told that I do the homing if printing only with extruder 1 is made with extruder 1 while printing with both or extruder 0 homing is done with extruder 0.

    This is because I want to have the maximum dual build volume set up in one profile.

    For dual printing with one extruder the build volume is 260x200x300.

    So let me explain why this could be a problem when doing print with only the second extruder (extruder 1).

    Let's assume you have position your extruder 0 (e0) on the 0,0 spot of the bed.
    Then you extruder 1 (e1) is roughly 35mm to the left (x+35).
    And that is what you ideally set as offset: X35 Y0.

    Let's go with this values for now...

    So if you home with e0 selected then e0 is at 0 e1 at 35.
    If you do a move with e0 selected to 260 (the maximum) then e0 is at 260 and e1 it at 295.
    If you do a move with e1 select to 260 then e0 is at 225 and e1 is at 260.

    So what if we now want to print only with extruder 1?
    Well you build volume is reduce to the build volume like if printing with both (220x200x300) because you make moves only with e1 selected but you homed with e0 so you cannot move to 0,0 with e1 selected because that would move e0 to -35 which is not possible. (Unfortunately Marlin allows this move crashing your head into the X endstop.)

    That is why I home with e1 selected when printing only with e1.
    Then e1 is at 0 for the firmware after the homing. And you will be able to move e1 to 260.
    e0 will be at -35 for the firmware, you can set this as offset if you accidentally make a move with e0 selected but why should you?

    I tested this and it worked correct with RC4, did not test yet with RC5 or the bug fix branch...
     
  2. Stian Indal Haugseth

    Stian Indal Haugseth Well-Known Member

    Joined:
    Sep 11, 2015
    Messages:
    573
    Likes Received:
    95
    I need to read this when not tired. Is this with the mirrored setup?
     
  3. Alex9779

    Alex9779 Moderator
    Staff Member

    Joined:
    Sep 4, 2015
    Messages:
    2,405
    Likes Received:
    731
    Not really. This was about how to print with left or right extruder only without setting the offset and why the dual build volume of 1.0 was only 220x200...
     
  4. Stian Indal Haugseth

    Stian Indal Haugseth Well-Known Member

    Joined:
    Sep 11, 2015
    Messages:
    573
    Likes Received:
    95
    Right. I have just started to fool around with testing extrusion and need to get a grip on the dual stuff. Think I might take a look at your S3D profile as well if I can find it.
     
  5. Alex9779

    Alex9779 Moderator
    Staff Member

    Joined:
    Sep 4, 2015
    Messages:
    2,405
    Likes Received:
    731
    Goto the links page in my signature then to my github profile. The repo is BigBox-Settings...
     

Share This Page