The mold was tricky to manufacture because I wanted to conserve the amount of silicone used. (expensive) I ended up modeling it in 3d so that I could get a good estimate of the volume of silicone that it would take to fill the two parts of the mold. being this cheap ended up biting me in the ass when used for casting.
The truss turned out to be extremely hard to get a good cast. The struts are thin and the details of the LM/SLA interface are very fine in places. The molten tin had time to cool of before it reached the bottom of the mold and there was also the issue of getting air out of the mold. This was further complicated by the fact that the mold was rather flexible and hard to keep “shut” due to the fact that I made it so thin. Maybe not such a good idea afterall… Just look at the number of rubberbands used to keep everything in place…
There where a considerable amount of failed trusses cast, sworn over and melted down again. late late at night and a couple of burnt fingertips later I had the four trusses I needed and even one spare if i where to break one during assembly. (I just do not want to use that mold again if possible.)
Failure ratio of at least 5:1