By Tom Mueller, Mueller AMS
Creating casting patterns using 3D printing is a technique that was pioneered by 3D Systems in the mid-1990s. The QuickCast® methodology enables patterns created in SLA to be a very fast and lightweight hollow pattern build style with hexagonal internal supports, produced without the time and cost needed for tooling.
SLA QuickCast patterns have been the leading type of additive manufactured pattern ever since, across the industry. Progress to transition QuickCast from prototyping into production has been slow: it has been used extensively for prototype castings, and some bridge manufacturing, and in the last few years has evolved into extensive casting for jet engine impellers. But now we are moving into a new era where QuickCast will become applicable in wider vertical segments.
At the Investment Casting Institute’s annual Technical Conference and Expo this week in Kansas City, Missouri, hundreds of foundry owners and employees are attending to discover new developments and technologies for investment casting.
At the event I will be presenting the ongoing research and development currently in play for 3D Systems’ QuickCast methodology. QuickCast has had some ongoing challenges with regard to cracking shells during the casting process. While this was solved using work-arounds, this really only made the methodology applicable to prototype castings. Recent years have seen some new development for QuickCast and, in collaboration with 3D Systems, I have been conducting research to make this solution truly viable for production-grade SA casting patterns.
A number of factors are increasing interest in using printed patterns for low- to medium-volume production including increasing demand for fast turn on casting orders, and increasing interest in “un-moldable” geometries generated by topology optimization programs.
During this research, studies were done to reduce stiffness in the pattern and have uniform stiffness in all directions to relieve the problem of shell cracking, while keeping file size, slice time and build time comparable to the existing methodology.
Creative new approaches to the QuickCast build were delivered by the research team, including notched walls in the structure and a new diamond-shaped build, and both look promising.
At the time of this blog post and presentation, foundry testing has not been completed. I will be happy to deliver an update in the coming months when we have fully-tested results showing how QuickCast continues to lead in the industry.