- UPDATE: test runs with 20% carbon fiber filled ABS from Techmer ES
- “Near net shape” approach with relatively large extruder
- Five axis CNC machine gives the final net shape
- Thermwood announces 3D Additive Manufacturing program
Thermwood Corporation, a U.S. based manufacturer of 3 and 5 Axis CNC routers, has announced a program to develop a 3D Additive Manufacturing system capable of making large carbon graphite reinforced composite thermoplastic components.
“Near net shape” approach with relatively large extruder
Thermwood’s systems utilizes a “near net shape” approach where a relatively large extruder, mounted to the machine, is used to heat, melt and deposit, or “print”, carbon graphite filled thermoplastic material to quickly create a structure which is almost, but not quite the exact final shape. That structure, when it cools and hardens is then five axis machined to the final net shape.
Plastic extruder integrated into CNC machine
These new systems will be based on Thermwood’s Model 77, semi-enclosed, high wall gantry machine structures, which are currently offered in sizes up to sixty feet long. The plastic extruder is supplied by American Kuhne, who developed a custom system to integrate the extruder both mechanically and electronically with Thermwood’s CNC machine. This allows not only the machine but also the plastic extruder to be controlled and managed by a central CNC control.
Second gantry enables “Additive” and “Subtractive” processes to be performed on same machine
With the addition of a second gantry, both the “Additive” and “Subtractive” processes can be performed on the same machine. The second “Subtractive” gantry will be offered as an option. Companies that already have five axis machining capacity and want to work with Additive Manufacturing may only require “Additive” machine capability as they can use existing equipment for the “Subtractive” part of the process.
Thermwood’s additive manufacturing systems will feature full six axis articulated additive deposition head, allowing it to build layered structures on both a horizontal plane as well as planes canted in any direction up to ninety degrees from horizontal. The company believes that this capability will be important as technology advances and more complex structures are required.
Additive process with 1-45-24 single screw extruder
Thermwood’s initial development machine, which is nearing completion, can make parts up to ten foot by ten foot by five foot high, is equipped with a 20HP, 45mm (1 ¾ inch) diameter, 24-1 L/D extruder and support equipment capable of processing over 45 kg (100 pounds) of material per hour. Despite the relatively heavy weight of the extrusion system and head, which are both mounted on and move with the machine, the machine generates impressive performance with high acceleration rates and high feed rate capability.
This is an ongoing research and development program and Thermwood Management cannot say when commercial systems might be available to the market, but they believe this technology represents a major opportunity and that “Additive Manufacturing” will become a significant factor in the future of manufacturing.