Requirements for the metal print project included fitting within a 2x2x4” area and using 1/4 of the print volume. Since LEGO minifigs are blocky and simplified, a LEGO figure would translate well into metal print parameters.
First Iteration, design parameters: LEGO Batman was designed in SolidWorks to fit within the available print area. All bridging and overhang was modeled to <2mm for printability and thermal management. The arms were given a thickness of <2mm with filleted hands joining to the body, reducing overhang.
Second iteration: To reduce warping and improve thermal management, overhang was reduced to <0.5mm. The neck was also thickened and a chamfer added to reduce overhang. The legs were joined into a single piece to remove bridging. An angular slice was cut from the hands so their print angle would be >45°. The entire piece was hollowed out to a wall thickness of <2mm for thermal management optimization.
Materialize print setup: Using Materialize software, block supports were placed underneath the feet to separate the part from the build plate; this minimizes residual stress by reducing the cross sectional area while anchoring the part to the plate.
Pencil supports were added to the cape to support local minima, providing a path to conduct heat away from the cape.
Print bed orientation: The part was oriented 45 degrees to the wiper blade to prevent damage due to friction against the blade.
Final part: Details came out relatively free of defects due to careful placement of supports and optimized design for thermal management. In future prints, warping at the feet could be improved with further reduction in wall thickness.
