One of our students, Joey Wood have been playing with his 3D printer.
Here are some details on the process he used to get this model made.
He designed the model in Autodesk Inventor, pulling dimensions from our real build-season CAD to ensure it would be (for the most part) to scale. He had to make a few exceptions and simplifications to the original CAD in order to ensure the model was actually printable. For example, since the drive-train was originally modeled to be constructed of sheet metal, he had to simplify the design into solid rectangular beams. If he had tried to feed the actual sheet metal CAD into the printer, the already thin sheets scaled down 12 or 13 times would likely be too thin for the printer to register. Also, he had to double the girth of the 4 2×1 aluminum beams making up the lift structure for fear that the original sized beams would be too thin and fragile. Once he had a CAD he was happy with, he broke it up into 6 pieces and sent the .STL files off to my slicing program, Cura, to be printed.
For those who are not familiar, a slicing program takes a standard 3D model, (in his case an stl file) and breaks it up into 2D “slices” that are typically .1mm-.4mm depending on the quality and resolution your 3D printer can handle. These slices are stored in a file format called G-Code, which the printer’s board can then read and turn into commands for its 4 actuators (X, Y, Z axes and a motor that feeds the plastic filament through a nozzle).
Some problems he encountered during the print include: curvature of the bottom layer of the print which is intended to be flat (This will happen when one corner of the model loses its adhesion to the print bed and curves upward), a long print time at nearly 4 hours, and inconsistencies between the main structural members that make of the lift structure.
However, the print went well overall and he found little difficulty in assembling the pieces. For assembly, he used a soldering iron to “weld” the plastic members together. While the fumes given off by PLA are completely non-toxic, he would not recommend this method as it involves warping the plastic and can burn it/you quite easily. In the future, if he were to replicate this model, h would try to find a more reliable method of fastening the pieces together for aesthetic’s sake. Perhaps a design that allows the pieces to snap together like a puzzle, and requires no other fasteners/glue/welding.
If anyone wishes to print their own Liftzilla, he have included a ZIP file with all the necessary parts. He printed his on a Printrbot Simple Metal in PLA, but feel free to experiment with your own set-ups and report back.