Today, we have studied creating complex robot programs manually again. Platonic solids were the subject of this study. Students tried to create a sequence of robot moves that produces a Platonic solid out of a 17cm EPS cube. We simply call this the robotic hotwire cutting polyhedra exercise. However, the size of our hotwire cutter became one of the problems because of its risk of crashing. We crashed several times but managed to cut some polyhedra at the end of the day. I think this exercise was helpful in repeating the basic robot programming in Grasshopper with a “solid” purpose.

The robotic hotwire cutting polyhedra exercise had many beneficial results. For example, it helped me to integrate architectural geometry and Rhino courses with robotic fabrication. I believe that the students better understood those topics now. It had also a nice fun factor. Students saw the difficulties and potentials of this new production technology.

In the above Grasshopper definition, we used the “Robots” add-on to program the motions of our Kuka KR-20. The polyhedron we intended to produce is an Octahedron with 8 identical triangular sides. You can see the available hotwire cutter is a bit larger than necessary. After the calibration of the tool and the position of the EPS block, we tried to create smooth motions to cut the sides. As you can see in the video above, the tool didn’t have to tilt to get to the correct positions. However, there are many external factors affecting the result of hotwire cutting, such as the power, the thickness of the wire, the speed of the robotic arm, and the density of the EPS. So, even the air temperature and humidity are affecting the outcome.