Week 2: Calibration and Nesting Objects

In this assignment, I build a simple calibration cube in part 1. In part 2, I designed Matryoshka dolls, goblets, and a cube tree for printing, and another spiral tower for display in Rhino.

Rhino, 3D printer

I followed the steps in https://www.youtube.com/watch?v=hHQA8muXvoc. The steps are to first generate a cube object by drawing a 2D square and extrude curve -> straight to make a cube with no upper and lower surface. Then, use planar curve to fill in the two missing surfaces. After that, I drew and copied 6 spheres, and moved them to the center of 6 surfaces. I used the solid -> difference to subtract the spheres from the cube to make the ornament. I exported the design to stl format ready for printing

I failed 3 times before printing this calibration cube. The failures includes not plugging in the filament, and not balancing the workbed correctly. Be sure to read the manual before playing with it because it can avoid lots of errors. By opening the stl file in cura3D and plugging in the USB with the TF card, I can send the design to the TF card and plug the card back to the 3D printer and print the result. It tooks around 30 minutes.

I started with the starter code of creating a stack of transformed objects. First, I drew a curve that mimics the doll shape, and revolve that curve around the Z axis. By changing the center of the bounding box Z to 0, I can ensure that the bottom of all dolls lie on the same xy plane. By reducing the scaling factor in each iteration of the stack geometry, the effect of creating dolls with the same shape but with different volume can be achieved. I was planning to buid larger dolls with more complexity in the curve, but I found even simple design like this in a small scale takes the printer 4+ hours to fabricate, so I want to stick to this simple design.

I get the idea from the class demo of create a row of transforming objects. Starting from the basic shape of the calibration cube, I wanted to design a tree with cubes as trunks and a stacked row of shrinking cubes as branches. Starting from the starter code, I changed the scale and offset values to connect the row of shrinking cubes. From this basic shape, I copied 6 more, and re-oriented their directions in space. By contatenting them on the trunk made of three cubes, the tree like structure is achieved. One thing I did not consider well is it is a bit large, which takes 5 hours to build for the 3d printer. Also, there are some artifacts when printing, and I think the reason is the PLA filament do not have enough time to cool down, which creates threads-like artifacts after printing it out.

In this design, I used the non-uniform, iterative scaling model. By first revolving the curve to create a goblet object, I modified the centeroffsets to place the duplicates with scaling on the xy plane, and changed the scaling factor to make the goblets in better forms. The printing part of this is harsh. The bed level may have some problem, which makes two of the goblets deform.

Besides using revolve curve around an axis, I tried to form my own object -- a spiral. By using the non-uniform scaling of the original spiral, I duplicated 3 nested spirals, and the wrapping creates the effect of a tower like structure. Due to the complexity shown in Cura3D, I did not print it out, and just want to show this interesting shape when I work along this assignment.