turning 3D printed plastic parts into metal objects is not a new concept. but we don’t see a lot of it and took pleasure in enjoying the documentary version of [3DTOPO’s] lost PLA metal casting process so much we figured you’d want to see it too.

The thirty-five minute video walks through every part of the process which we originally learned about in September of last year. The process was developed as a way to fabricate parts that will be used in high-stress applications. For instance, the part seen above is a mounting bracket for the ball screws that moves the Z axis on a substantial CNC build he’s been working on. A plastic part will break under the strain so he needed to make it out of aluminum alloy.

To start, the piece is modeled and printed in plastic to check the fit. once it’s just ideal he scales it to 103% and prints it again to account for the shrinking of the metal as it cools. The next step is visualized above, adding paths using rigid foam insulation that allow for the metal pour and for air to escape. This is packed into a plaster and sand mold which dries before being cooked in a furnace to vaporize the foam and PLA. This leaves a best mold for the metal pour.

After the break you can see a 5-minute introduction version of the project.