Printing rectangular grid

  • I am trying to print an item with a rectangular grid (using PLA on Ultimaker 2+):

    item with a grid

    Holes are 4x4 mm, distance between holes (wall thickness): 1mm. I am printing with 0.4 mm nozzle.

    Unfortunately, Ultimaker Cura generates G-code which prints each rectangle on its own and in a quite a bad way:

    print preview

    The printer head tries to draw a rectangle, then moves in the direction opposite to a last laid line, which with not perfect adhesion of single line messes up the print pretty badly: it often picks up last rectangle side and drags it.

    Any way to change the way Ultimaker Cura approaches to lay out the grid? I would imagine that long lines that are connected to other lines would adhere to bed much better than individual squares, but I don't see any options that would allow to alter it.

    I agree, the slicing is not optimal. Maybe you can make an Issue at github.

    Another thought why this might be bad: the printed piece will will have very little tensile strength as there are no strands running along the whole thing keeping it together.

    It's difficult to slice for 1mm walls with a .4mm nozzle. You'll do much better with walls of .8mm or 1.2mm. Once you go beyond 1.2mm the slicer can start to use diagonal lines to fill in for any value you want, but less than that you really want to stick with multiples of your nozzle size.

  • Trish

    Trish Correct answer

    4 years ago

    Slicers never create a grid by crossing the already printed lines - they print perimeters and thicken them into a shell. So if the picture that is to be printed is a #, it does not lay down first the || and then the = crossing over it, it lays down an inner square and then builds the rest to get to the shape. This operation rule is held for shells, but not for infill patterns.

    As you describe the printer picking up the printed, you have adhesion problems and your first layer might be not level or too thick.

    You might also want to enable "print thin walls" and use 2 or 3 perimeters.

    I ended up re-leveling the bed and made the walls slightly thicker (1.2 mm). It, of course, didn't change the printing pattern, but it did manage to print properly. Still, I think printing internal holes this way is wrong, especially with an adhesion plate present: it would hold much better if as much lines as possible ran across bottom layer ending on both ends at the adhesion plate...

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Content dated before 7/24/2021 11:53 AM