In order to get a perfect casting ,we should consider some important factors before starting design.We have some experince as follows
1st Try to avoid thick section,so as not to create shrinks when hot pouring
2nd Don't change wall thickness suddenly,otherwise the organization will cause segregation.and the thin section will become cold and harsh.and the thick places will be lack of iron fluid
3rd If the casting is too thin or only 0.005m thickness,it should be pay special attention to the smoothness of the cavity when making the shell,otherwise there will be more defective products
4th The heat transfer rate should be calculated according to the smallest part of the section,the high transmissible metal can be poured castings which is below 0.010m thickness.
If the alloy metal flow ability is good,there is no need to consider the running and feeding system.
5th When some high-alloy steel and stainless steel are in the molten states,their flow ability is not good and the thin part will be lack of metal fluid.The medium heat transfer rate metal include stainless steel, brass and bronze.
6th Try to avoid under cut when making design, it is necessary to use split die.Also pay attention to the was pattern in order to reduce the defective products.