Efficient nesting of layer segments for Cut Layer Additive
Thermwood has introduced a new approach to large-format additive manufacturing (AM), which it believes offers a lower cost route to leveraging the benefits of AM but with materials which can’t typically be 3D printed.
Known for it’s Large Scale Additive Manufacturing Technology, the U.S.-based company has taken its 50 years of experience in building CNC control systems, and applied it to a process called Cut Layer Additive.
At first glance, the process seems more akin to sheet lamination than Thermwood’s extrusion-based LSAM 3D printing process, but it's actually a completely different approach. Rather than printing, layers are cut from thick sheets of material and assembled. Each layer is separated into two or more segments and once cut, are re-connected using puzzle joints, with dowel alignment holes in place to ensure straightforward assembly. Depending on the material, which Thermwood says can extend to just about any machinable material, the overall process including cutting and assembly is said to take, ‘at most,’ the same amount of time and labour as it does to 3D print the same near net shape part.
Aerospace layup tool made made with Cut Layer Additive
Parts are produced hollow, and Thermwood demonstrates one example of a large aluminium aerospace trim fixture featuring walls that are around one inch thick. The company says it uses ‘less material than just about any other way of making it.’ In another example, Thermwood shows how parts can be made from porous materials and penetrated with a thermoset resin, which soaks and hardens into the structure to make a large thermoset composite part. The process was used to manufacture a 12-foot-long aerospace layup tool for a material cost of 2,000 USD, and in less time than it would take to additively print the same part.
Thermwood describes the process as a ‘simple idea, executed with cutting edge technology,’ which could have ‘a profound effect on a lot of areas.’ The real backbone behind the process appears to be its machine intelligence background. Claiming that Cut Layer Additive doesn’t require programming, ‘in the usual sense,’ Thermwood says it has taught its machine control technology to create Cut Layer Additive parts by simply sending a CAD file and telling it a set of desirables such as material choice, wall thickness, nesting layers, etc. The machine then automatically creates the additive part and layer segments needed to make it, nests them on your chosen material and creates an internal multi tool program to cut it out. The machine also provides information, including a QR code, to assist the operator with assembly, which can be done with bonding, screws, rivets and bolts.
