Original image of "Little my"This week assignment is to make something with Vinyl Cutter and Laser Cutter techniques.
For the Vinyl Cutter assignment, I have decided to make a vinyl print of one of the characters from the stories about the Moomins by Tove Jansson. After taking the initial raster file and performing some image processing (to sharpen and smoothen the edges), I have vectorized it. Finally, I have printed this image on a black vinyl and after around half an hour of weeding, the result looks as follows:
Original image of "Little my"
Final vinyl print
For the Laser cutter, our assignment was to design and lasercut a parametric press-fit construction kit. The hardest part was to come up with an idea of what to print. After some thought, I have decided to build a model of DNA, which would also visualize the A-T, G-C relations:
DNA model
I started from a few simple pen-and-paper calculations and sketched 5 basic building blocks that would be required for the double helix of desirable dimensions. I then drew them in FreeCAD.
Initial sketches
FreeCAD Layout
FreeCAD turned out to be a helpful tool, as it also allowed me to use parametric constraints. However, when it came to exporting the 2D files from FreeCAD (within the sketcher tool), I have struggled a bit with the wrongly chosen drawing plane (X-Z), which I was not able to rotate later (the problem could have also been caused by the overconstrained plot). I have then decided to redraw everything in AutoCAD (thanks to Zack and Ben for pushing me to try this!). Note that in the final design, I had to account for the finite size of the laser r=0.17 mm, which was deduced in our prior group assignment. Finally, I have sent multiple copies of the final layouts to the laser cutter.
Autocad layout
Cutting process
After 30 minutes of printing, the press-fit construction kit was ready and I have started building basic objects with it.
Ready press-fit kit
First attempt: some sort of insect
The final DNA model also turned out quite well. The minor issue was that I did some of the calculations in my head (instead of using powerful FreeCAD capabilities). As a result, I have made a small mistake, overpredicting the radius of the helix by a factor of 2. Therefore, the stable version (very stiff) has a smaller radius, and no A-T, G-C relations:
DNA structure: Stable version
DNA structure: Complete, but unstable version
However, I was still able to implement my earlier goal (with all the internal ATGC intricacies), though I had to leave some fraction of the sections slightly weakend, which resulted in quite a fragile structure.
