Cornetto Muto (Mute Cornett)
by Gernreich, published
This is a Mute Cornett designed by Steven Silverstein: http://silversteinligature.com/
I did nothing but take his measurements and put them into stl files. The Cornett needed to be cut into four pieces to fit into my print area. To facilitate gluing the pieces together I created alignment cones meant to keep the pieces aligned in the X-Y plane during the glue up. These truncated cones are the negative space at the center of the Cornett. I glued each piece together with two part epoxy. To keep the internal alignment cones from getting glued as well I wrapped the alignment cones in silicone embedded parchment paper. Both the alignment cones and the pieces of parchment paper came out with no fuss.
Print Warning! I went beyond the normal print limits on my Rep2 to cut down the number of sections from five to four. I edited the gcode to prevent the nozzle from clipping the top of the sections in the end code section. For example one of the parts is 157mm tall. The nominal end gcode calls for the z-axis to be moved to 155mm. I edited the code to move the z-axis to 158.
I have tried printing these both solid and with three shells and 15% infill. At .34, .15 and .10 My main goal is to get these pieces air tight. They were not entirely airtight so I coated the whole Cornett inside and out with a coat clear Shellac. When the Cornett is assembled the lowest note played should be A440.
I printed the alignment codes at 99.5% scale, 2 shells 5 percent infill, and .34 layer thickness.