By Nancy Holt, director of operations, 3D Systems On Demand Manufacturing, Seattle
At the RAPID + TCT event this year, 3D Systems displayed a 2.5 m high investment casting pattern of a stator ring at its booth. That pattern was created using the innovative QuickCast methodology that enables parts to be quickly printed using SLA additive manufacturing to create a very lightweight, complex honeycomb shape that can be burned out easily during the casting process.
Many people ask if this is produced using 1 massive SLA 3D printer. It’s not. It is crafted in CAD into smaller parts that are more easily printed. This entire pattern consisting of 8 parts was created in under a week, using 5 SLA 3D printers at our Seattle-based On Demand Manufacturing facility.
Once each part is printed it is put into a spinner to remove the excess resin. The team has to carefully remove the supports from the SLA prints and sand paper away any layer lines by hand. Once inspection is complete the parts are glued together using epoxy resin and the seams are finished to be smooth before going to the foundry.
While it is a detailed process, it is amazingly fast and inexpensive compared to traditional processes for making large casting patterns. If this pattern was completed using traditional wax molds, just creating the tools for the wax pattern could take 9-12 months. The cost of the tooling alone is estimated to be about half a million dollars.
This SLA Quickcast stator ring took 6 days to print, with the finishing taking a couple more days, and the cost is under $20,000.
Using 3D printed investment casting patterns means customers can reduce risk – risk of mistakes, of needing costly design iterations. Many manufacturers use SLA casting patterns for prototyping prior to going into full, traditionally-based investment casting because of the low cost, but SLA patterns can and are increasingly used as full production patterns. A further advantage of 3D printed casting patterns is that the designs can have more complex geometry than designs created using tooling, the part can be lighter weight, and far more functional.
And while talking of lighter weights, the SLA printed stator ring pattern was just 32 pounds in weight. Imagine the weight of the same in wax!
Our team will produce any where from 24-30 complex SLA pattern assemblies per month along with many projects using both 3D printed wax and SLA for smaller patterns. Often times, especially with large complex assemblies, repeat production orders continue for several years and hundreds of patterns
We are a customer-first operation – we will be tasked with some truly demanding projects and deadlines and we will take it on and figure it out. For the team it’s all about watching a complex pattern come together. We are craftsmen, every single surface of a pattern is touched by hand and you can ruin a part very easily without true attention to detail. Seeing that perfectly finished pattern go out to casting is the biggest reward for us all.
The 3D Systems’ On Demand manufacturing services facility located in Seattle, WA., is focused exclusively on expert services in 3D printed wax, PMMA and SLA casting pattern production.