The difference between CNC machining and Vacuum Casting

Both good rapid prototyping solutions CNC machining and vacuum casting is common process using for prototype making or low volume production. Which solution is determined depending on the parts construction,order quantity of one batch and the material using for the custom-make parts.

Well,let’s talk about the difference between these two prototype process fast turnaround CNC milling and vacuum casting production.  

① CNC machining should CNC milling or CNC lathe the parts each by each piece,while the vacuum casting first make one master and to make the silicon mold according to the master, then using the silicon mold to copy the parts is OK.

② The available material will be different. CNC milling plastic parts like ABS ,PP,PMMA is exactly ABS plate ,PP plate and PMMA plate.But the ABS parts,PMMA part and ABS part come out from vacuum casting is ABS type,PMMA type or PP type not the real ABS real acrylic.

③ The manufacturing lead-time is different. Normally the production lead-time is shorter for vacuum casting over than CNC milling.Because vacuum casting is fast production once the silicon mold is ready just need copy the parts and one mold is no problem for 8-15pcs even 20 pcs.

④ The precision level if in CNC machining is much higher than vacuum casting.Because the vacuum casting process existing the shrink issue.

⑤ The surface finishing is different. The prototypes/plastic parts request painting as protective surface,the parts done by CNC machining is OK to apply painting then bake in oven to dry the painting as fast. But for the parts done in vacuum casting is only drying in nature or bake with lower temperature.