Part Buyers Authority Issue #5

13 Visit partbuyersauthority.com to SUBSCRIBE or CONTRIBUTE a s an author. molds is the surface finish, this is due to the layer by layer print creating horizontal lines on all surfaces. There is a solution that involves careful sanding of mold wash and reapplication to get a much smoother finish that is more aligned to traditional sand casting. 3D PRINTED PLASTIC TOOLING We recently acquired a Stacker S2 3D printer, as seen in Figure 3, to allow us to print temporary and long term production tooling for our customers. Printed plastic is a technology that has been around for many years but is now becoming more mainstream in the foundry industry because of more economical machine pricing. With 3D printed plastic the foundry is able to rapidly develop first article tooling without the labor and costs associated with wooden tooling. Plastic patterns can be designed for replacement parts as well as the extended production runs. Because the plastic costs fractions of what wooden tooling costs the patterns are effectively disposable meaning no storage costs for customers and when the job comes around again Contact: ETHAN EDWARDS [email protected] foundry can use 3D printing to produce a casting in the time it would take to even receive the pattern from a pattern shop. The rapid prototyping nature of 3D printing allows quick modification to any design or casting material changes with no downtime since there is no pattern that needs to be modified. All that needs to occur are the changes made to the 3D model and a new sand mold or plastic pattern can be printed in the same day. The modifications can be implemented within minutes of the results from the first casting being seen. Lastly, there is an abundance of cost savings for the customer as there is no hard tooling, no need for storage, and no repair/upkeep. Everything can be stored on a flash drive to be used again in short notice if that particular casting is needed within a couple weeks. a new pattern is printed and attached to existing cope/drag boards. The 3D printed plastic process we use is known as Fused Filament Fabrication (FFF). This entails a heated extruder that extrudes the plastic in the desired geometry line by line from start to finish. The 3D printer is capable of printing very fine layer heights, less than 0.1mm in height, giving tooling equal to that of wood. All manner of pattern equipment can be printed from the pattern itself to individual pieces to be assembled into a much larger pattern or coreboxes, an example of which can be seen in Figure 4. ADVANTAGES These technologies in regards to sand casting provides several advantages to the foundry that are passed along to the customer. The biggest advantage to 3D printing is reduced lead times. When using 3D capabilities the customer can expect to see a 2-4 week lead time from order placement to delivery. The Figure 2: Partially assembled 3D printed mold Figure 4: 3D printed plastic core box, showing interior cavity Figure 3: Trident Alloys’ Stacker S2