OK, the last weekly assignment is ready (PS11.pdf). Note the dual due date: the digital parts of the assignment are due a week from today (Tuesday Dec 4) and the physical 3D print of your model is due at the prototype session.
One student asks:
"I have access to a different 3D printer, so I'll be using that for assignment 11. I was wondering if there was a specific size of the curve you would prefer (an inch or two in diameter? palm sized? bigger?). I didn't see this specified in the assignment (though the OpenSCAD program sets the curve size to 4 by default)."
The curve_size parameter just sets the relative scale of the thickness of the tube that follows your curve and the overall size of the model. It does not set the actual physical size of the object. There are no meaningful intrinsic units to the STL file that is produced. You will need to scale it using the software that controls your 3D printer (which goes for printing in Pierce G11 as well). In Pierce, they will help you scale it so that the estimated printing time and amount of material used are reasonable. (The people in the lab there have been kind enough to provide the plastic used by the 3D printer at no charge.) If you have access to another 3D printer, you are welcome to print your object at whatever absolute size seems reasonable to you: you can weigh the printing time, material used, the size capacity of the printer, and your personal preferences in selecting a size. However, I'd recommend that you not print your shape any smaller than two or three centimeters across. (Larger, if reasonable and desired, is fine.)
Also, I should make things explicit to ensure I am giving credit where credit is due: as implied by its name, the main OpenSCAD file you will be using (if you go the OpenSCAD route) is adapted from one written by my friend Laura Taalman, aka mathgrrl.com.