Tuesday, November 29, 2011
Cerro metal molds
I reached a point in my 1/3 scale wheel lock project where I had all the master parts made and was ready to cast multible parts. In all my past miniature projects I have made various type molds for injecting the wax to be used for investment casting. For the wheel lock I decided to use plastic parts instead of wax because of the greater detail and sharp corners that can be achieved with plastic. In order to inject plastic into a mold I needed a mold material that could hold up to the higher temperatures and pressures used with a plastic injection machine. Following are a few photos of the mold making process and the cheap press I made from scrap parts, It is used to compress the Cerro metal quickly after the molded Cerro is poured in the mold. This compacts the Cerro metal causing a tighter crystal structure in the metal which produces extremely fine detail.Another benefit of the cerro molds is the expansion of the eutectic metal thus parts that are not smaller due to mold shrinkage, the cerro also cools the injected wax or plastic very quick which reduces cycle time of making parts.
To see the 1/3 scale wheel lock project go to Miniature Wheel Lock