I’m going to get into our 3D printing setup and process and how it might benefit those that are looking in getting into print-to-cast jewelry manufacturing.
A little background into our company and design process; we are a 54 year old company that began work in 1969. Our original designer and namesake has since retired and we currently have a design team that produces around two full collections a year consisting of close to 100 individual designs in total. Traditionally, our designers made wax carvings, or fabricated models that were then cast or molded. We cast in-house and produced around 44,000 castings in 2022. We mainly work in Sterling along with 14K, 10K, and Bronze. Within the last two years, our designer shifted to designing in Rhino/Matrix, and we began 3D printing in-house with the goal the goal of printing to cast.
We began small, working with an Elegoo Mars 2 Pro with a castable resin. We experimented with numerous types of resins and landed on Stuller’s Open-Grow Spectrum HD as working the best for us. It was a huge learning process, that required much fine tuning and experimenting to produce good quality castings. The biggest issue, was the burnout. These castable resins are only partially made of wax. We had to coat the prints in Pro Cad Liquid Barrier before investing, and then we invested in R&R Plasticast instead of our typical Ultra-Vest. We were still having mixed and inconsistent results with pitting and surface imperfections. We noticed this was typically on casting sections that did not have much space to escape, such as pendant bails or locations furthest away from the sprue. In response, we added sprues to the areas. We also learned that our initial ramp needed to be slower, otherwise the resin would reach it’s ignition point to quickly and would interact with the investment to cause casting imperfections. We slowed our initial ramp to 300F and held for 4 hours, and also slowed our other ramps to 1300F before dropping to casting temps. Results were better, but we still were unimpressed by limitations of the Elegoo printer itself, and the process to produce these results ate into our regular workflow time allocations, and if we didn’t do everything exactly right, then a whole day was wasted.
We looked into buying a better resin printer, but then got turned onto Solidscape printers from a local colleague of ours who had a 3Zs they were looking to sell. After some research, we decided to purchase theirs for a very reasonable price. The learning curve for operating and maintaining the machine was much harder than the Elegoo, but after some time, we were able to make our first print and subsequent cast. The results were phenomenal. The difference being, the Solidscape prints in wax with a melting point almost identically to the injection wax we use. Many on this forum are probably familiar with their technology, Drop on Demand. The print is similar to FLM where it has an XY arm that drops build material onto a build plate. The difference is, the Solidscape’s support material completely surrounds the build material, which is then dissolved away in a solution during post-processing. Print times are exponentially longer, we have had 60 hour prints that we run over the weekend. Maintenance is different as well; the 3z requires continual upkeep and cleaning.
The printer we purchased was over 10 years old, so we were expecting some repairs. The motor that drives a cutter (which planes over each printing layer) failed and needed to be replaced. (Note: subsequently, we realized it was a bearing inside the motor itself, which we replaced for $10. So now we have a refurbished motor on hand in case the Y-Axis motor fails). The programs used for the printer are also far behind the other CAD tech that we use, but it works. Trial and error, was a big part of this, but it paid off in the end where we are able to consistently produce great models with minimal cleanup. The only drawback is that the printer support is expiring at the end of this year, so we are learning how to repair what we can in the event that Solidscape can no longer provide us with service.
So now are process is this; rapid prototyping on the Elegoo, and printing to cast with the Solidscape printer. Our turnaround from final design to casting the model can be within 72 hours. It’s help contribute to an effort of pushing our design calendar up a year, and has been a great learning process.
Let me know if anyone has any questions with printing to cast, or any questions regarding our process, the machines and tools we use, or anything else in general.