molding & casting
I wanted to experiment with using a black and white png to create my mold. In fab modules, white is mapped to the highest point and black is mapped to zero. In Photoshop, I turned on the grid and the snapping feature. I then drew shapes using the pen tool.
![](mold1.png)
I applied gradients to the various shapes to create facets.
![](tile2.png)
I applied one transparent radial gradient over the entire design so that it would be highest in the center and lowest on the edges.
![](tile3.png)
I had some problems with the fab modules code when I went to actually mill this design on the Modela. When I tried to compute the tool path from the png, I was getting bad results or crashing the program. It turned out that using the 1/8" end mill in the calculations was causing something in the program to fail. I decided to use a smaller tool (1/16"), which fab modules was able to calculate. I made my piece a little bit smaller hoping it wouldn't take eternity, but it did end up taking a very long time (fab modules doesn't estimate the milling time like the Windows software does).
![](tile4.jpg)
The rough cut only took about 15-20 minutes, but it did not go deep enough the first time. I changed the cutting depth in the 3D settings and then did it again, and it worked. The finishing cut took hours! Overall, I think it took almost 5 hours to mill, but luckily I don't think I blocked anyone else! The walls of the outer square are for some reason not completely smooth, but I can live with it. I'm very happy with how the rest of the small details turned out.
![](tile1.jpg)
Many of the sharp points ended up being rounded because of the diameter of the mill, but I actually really like the way that looks too.
![](tile5.jpg)
Looks like I ended up with some air bubbles in my silicon, but they aren't too bad. I decided to try casting the dry stone anyways while making a second silicon mold.
![](tile7.jpg)
The strange edges actually look pretty interesting! I guess if you want fab modules to cut clean edges, you have to incorporate it into your design or else it will do something like this.
![](tile6.jpg)
Despite the air bubbles, I like how the dry stone piece came out!
![](tile8.jpg)
I smoothed down some of the edges using a metal spatula and then sanded it.
![](tile9.jpg)
I made another mold using the vacuum chamber, which had much fewer bubbles.
![](tile10.jpg)
However, after two more tries casting in dry stone, I had lots of bubbles. I suspect this might be from the vacuum chamber, but I'm not sure! The best outcome was my first one, but I tried hand-painting one of the later ones which had fewer bubbles with gouache.
![](tile12.jpg)