How 3D printed sand molds improve your casting experience

By C.A. Lawton | March 11, 2020
pattern blog (5)

Additive manufacturing, or 3D printing, is the process of making usable objects from digital models. By building up successive layers of material, additive manufacturing provides access to capabilities not available with traditional manufacturing processes. Not only can additive manufacturing technology build objects using materials such as plastics and metals, but advances have proved successful in printing sand molds and cores on large scales.

In 2015, the C.A. Lawton Co. partnered with the Wisconsin Manufacturing Extension Partnership (WMEP) and the Milwaukee School of Engineering (MSOE) Rapid Prototype Center to perform trials on printed sand molds and cores for large and complex castings. Because the C.A. Lawton Company specializes in large, complex, and low-volume castings, the ability to skip the expensive and sometimes limiting pattern step and go straight to the printing of the molds and cores has proven to provide many advantages to our customers.

Some of the advantages of Sand Printing are:

  • Fast: Printed cores and molds are turned out in days. Traditional core boxes can take many weeks to build.
  • Accurate: Feedback from the first part in easily incorporated into the digital model resulting in dimensionally accurate parts. This is not always practical or even possible for traditional patterns due to the scope of the adjustments (< .020”) and the high expense of altering existing wood or urethane tooling.
  • Near-Net: Because 3D printed sand molds do not require a draft for pattern extraction or special accommodations for under-cuts, molds are built to exact profiles resulting in weight savings and less machining.
  • Surface quality and contour consistency: Printed sand molds produce surfaces many degrees higher than foam tooling.
  • Complexity: There is often no need to watch out for undercuts. Sand molds allow for interior features that are not possible with traditional cores. Additional complexity can be added in instances that may not have been previously possible.
  • Integrated: Complete molds can be printed inclusive of internal features. Cores are integrated into the mold.
  • Cost-effective: Lawton produces quick and efficient models and prototypes without expensive patterns. This is ideal for large, low-lot size / single run parts and complex cores. 
  • Combination: 3D printed complex cores can be combined with traditional in-house sand molds.
  • Easy de-coring (after casting): Due to low binder content of cores and easier outgassing of components, de-coring is easier.

Ask your rep if 3D sand molds and cores are right for your project. If your application is 1,000+ pounds and includes complex parts, this method might be right for you. Call us today to learn more!