For the composites assignment, I want to create something using steel as reinforcement on a concrete matrix. Nothing new there, but it is for me. I also want to try making a semiwoven lattice using CNC bending of 1/8″ diameter carbon steel. I´m lucky to have at hand an small desktop bender, a DiWire, wich is (hopefully. ) up to the task.
The subject object for this assignment is an small stool, which will have a seat volume made of this orthogonal steel structure, which in turn will be put on an EPS mold cavity made by a CNC hot wire cutter. The concrete is also reinforced using fine gravel. Here are some proces sketches explaining the object and method.
Since the DiWire bender software works with .SVG files, I had to convert the Alias generated DWG files in Adobe Illustrator. Once there, I´ve opened them, checked scale, lenght and material setup to feed the steel wire. Once I´ve started bending, I tagged them with postits to avoid hassle while assemblying.
After bending them, I cut / trimmed the excess rod with a big bolt cutter, which was the only tool I had at hand ( I wasn´t allowed to cut the rod with the shear for fear of leaving indentations on its edge.) Once cut I had to bend some parts back to elliminate springback, and welded the transversal loops. After that I laser-cut a pair of simple assembly jigs with the correct spacing between sections, and to allow me to insert the other orthogonally placed wires.
Tying up the perimetral intersections to improve stiffness. Cutting the mold for concrete casting in EPS using a CNC hot wire cutter:
Setting up the steel structure in the mold, concrete preparation and casting. I expect to release the mold tomorrow around mid – day. There where slight trimming errors and springback deformation in the wire structure which resulted in uneveness far from the nice and exact CAD drawing. Not very funny thing but definitely a learning experience on something I´ve never did before. In my defense I can only said the famous (designers.) Campana Brothers are famous for the deliberate exploitation of their inaccuracy… 😀
After leaving it for 16 hours, I considered it was ready for demoulding, but since it´s still a little damp, I´ll try a seating test on it in 10 hours more.
To access the files for this assignment, please go here: