The original Chrysalis grillwork was designed to mimic the structure and function of an acoustic guitar soundboard. The model was created in Pro-E, and was a combination, or superposition, of two separately designed CAD files –a “bold” grill and a “fine” grill. The idea was that the bold tendril pattern would be primarily structural and transfer the tension from the bridge to the outer 13 attachment points (The Ridgewing re-design kept the identical grill attachment point pattern). The inner edge of the grillwork was unattached, and the bridge only made contact with the grills on their flat hard points. The bridge cleared the body center and touched only the grills, so the bridge and grills were free to “float” and vibrate like a wooden acoustic guitar soundboard. The fine grills were designed to carry the vibrations to the taught Mylar membrane that acted as the Chrysalis guitar’s sound-producing structure.

Rendered as polished gold because why not?

The carbon-fiber Chrysalis grills worked very well, but are extremely labor-intensive to make using a silicone mold. To minimize manufacturing cost, the Ridgewing grill was re-designed to be made out of die-cast magnesium. The die-casting tool to make them costs about the same as a very nice new car, but then it excretes finished grills. The fine grillwork of the original Chrysalis design was too thin for the die-casting process, so the grills had to be re-designed. The design task was to make a simpler grillwork design with a minimum cross-section in the range of 2,5mm – 3,5mm, and of course it also had to look real pretty.

It turns out it is pretty easy to make an unappealing grill design, and surprisingly difficult to make one good looking. Defining “good-looking” for a grill is an obscure exercise of the imagination, but you know it when you see it. Technically, each tendril is pretty straightforward to create.  Each is an individual “loft” in CAD-speak, with a loft being defined by 1) a beginning profile, 2) an end profile, and 3) a three-dimensional curvy line or “path” that connects the two. Push the Go button, magic happens and Sha-ZAMM, you have a beautiful winding tapered tendril to rotate this way and that and admire. OK, you think, now let’s just go and make a bunch of them.

The problem is that, while each individual tendril usually looks beautiful in its own right, especially when rendered in polished gold (my favorite), when you start hooking tendrils together, life starts to get very complicated. The tendrils are created and melded together in a complex tree structure of relationships called “dependencies”. You create tendril “A”, then tendril “B”, then you want to join them with a tendril “C”. Later in the design you want to create a tendril “R” to join tendril “B” with tendril “M”, but tendril “M” was designed to join tendril “C” with tendril “F”, which joined tendril’s “D” and “E”, etc.. To make things even more challenging, the complex tendril shapes, surfaces and dependencies not only give you a headache, but they also give your computer a serious headache of its own. Re-building the entire model for each new tendril or design tweak takes some time. Toward the end of the design it provides enough of a break to allow you to go get another cup of coffee, look over yesterday’s mail, and do some stretching exercises. Then you come back, and there is a 50-50 chance that while you were away the design “blew up” with that latest tweak, and you go “What the Hell?” and restart.

Drilling down into the design to try and identify the tiny flaw or flaws that caused the latest blowup, and then doing it over and over again for every tendril, becomes an obsession. But it is a necessary obsession, because until you root out every last little flaw, you ain’t got no grill. And when you finally get it done, and it looks so nice you want to lick it, you look back at a highly magnified picture of a dragonfly’s wing pattern and go “What the Hell?”

If, like they say, mental stimulation helps prevent dementia in old age, then keeping track of grillwork tendrils should push you right back to child-mind. So I’m not quitting.