The United States develops the world's largest composite 3D printer to produce driverless steam

Not long ago, the US company Digital Therwood original equipment manufacturer Local Motors has developed the world's largest composite material 3D printer, and completed the installation and testing of the equipment. The 40-foot-long (about 12.19-meter), 10-foot-wide (about 3.05-meter-wide) 3D printer is used primarily to produce Local Motors' self-driving electric car Olli, which has IBM Watson's advanced cognitive computing capabilities. . Passengers can communicate with Olli on the way to the car, asking questions about the vehicle's operating status, where to go and why the route was chosen.

Therwood explained that the printer is the largest additive manufacturing (LSAM) device it developed, the industry's first extruded 3D printer with built-in CNC machining capabilities. LSAM is capable of producing large parts of fiber reinforced thermoplastic composites. The equipment adopts a two-step process and a near net shape production process.

First, the parts are printed layer by layer through a 3D printer, where the part size is slightly larger than the final size, and then the CNC is slightly trimmed to obtain the final part size and shape. In the process, the 3D printer runs in free space without the need for molds and tooling. Two gantry cranes assist in the simultaneous printing and cutting operations on one LSAM device, and the two gantry cranes are responsible for printing and cutting tasks.

The equipment differs from the 2016 BAAM (Big Area Additive Manufacturing) equipment developed by Cincinnati for the Local Motors Olli Pilot Project, which is capable of producing a wide range of molds and parts. The key difference between BAAM and LSAM is that they have different extrusion capabilities. The former can print 80 pounds of material per hour, while the latter has 3 different extrusion heads, which allows the extrusion rate of the device to reach 150, 300 per hour. Even 500 pounds.

In addition, the BAAM system compresses the material during the printing process in a circular mechanism, while the LSAM uses a servo-controlled wheel to follow the stacked polymer and compress it. At the same time, the BAAM system relies on a moving print substrate to control the z-axis height, while the LSAM secures the substrate and moves it by moving the extrusion head or processing head. The BAAM's maximum print size is 20 feet by 7.5 feet by 6 feet, while the LSAM prints a range of 10 feet wide and 5 feet high, extending the substrate to 100 feet in length if needed. LSAM's raw materials are industrial grade pellets from Techmer PM, which contain 20% carbon fiber and 80% ABS plastic.

According to Local Motors, LSAM will be used to manufacture the vast majority of 3D printed Olli, while BAAM is mainly used to print Olli's pedestals, wheels, interior panels, molds, etc. in current Chinese projects. For the moment, two devices cannot work in tandem.

In order to further increase the rigidity of the components, they also plan to further increase the ratio of thermoplastic resin and carbon fiber reinforcement in the future.