Study compares rapid tooling technologies

Rapid Solutions (Nashotah, WI, 71), a division of U.S.-based custom molder and design engineering firm, Dickten & Masch, recently evaluated two selective laser sintering (SLS) and two stereolithography (SLA) rapid tooling options side by side. The study was conducted to assess each technique’s advantages and disadvantages in order to establish which system offered better commercial potential. Results of the study were published in DTM’s third-quarter 1998 newsletter Horizon.

The study involved making rapid tooling for a part with “fairly challenging” geometry using the different methods and assessing the quality, cost and production time of the finished product. The four rapid tooling methods used in the study were two versions of DTM’s SLS process–one using the new RapidSteel 2.0 material, and one using a new copper polyamide material on a Sinterstation 2500–and two variations of 3D Systems’ SLA processes–KelTool, which uses a type of steel, and Direct Aim, which uses an epoxy plastic.

The size of the mold inserts to make the part were approximately 152 mm x 317 mm x 38 mm. Rapid Solutions estimated the lead time to create conventional tooling for this part would be 16 to 18 weeks for a two-cavity mold and cost as much as $100,000 (all figures in U.S dollars).

The study found that on the basis of cost, size of build envelope, build time and other factors, DTM’s SLS rapid tool process using RapidSteel 2.0 was superior to either of the 3D Systems rapid tooling methods. For example, total costs to build the inserts using the KelTool method was reported to be $34,000 or 39% more than the $20,500 it cost to make SLS inserts. Also, the lead time required to build SLA KelTool inserts was reported by Rapid Solutions to be two to three weeks, compared to a build time of about five days for the SLS inserts.