Dynamic Machine Axis Beams
Axis Beams
The basic principle of using composite materials for machine tool structures is stiffness driven; bringing high stiffness-to-mass ratio and added damping properties compared to steel.
On any cutting or milling machine, horizontal or vertical beams are significant structures for machine performance. The mass and stiffness can limit the machine’s working area, accuracy and acceleration. Composites allow the weight to be reduced by up to 50%. In contrast, stiffness can allow faster acceleration for the same deflection, which is essential for the positional accuracy required to cut to a high tolerance.
CompoTech is continually developing our unique machining process, which allows accurate fibre placement and pressing of square sections to produce beams with the straightness and accuracy required.
The process development also considers the internal structure that manages the torsional stiffness and contains the internal inserts for threading. Composite structural design must consider the linear rails, drives and other attachments, with the inserts placed appropriately for fastening.
Laser Cutter Gantry
The benefits of composite axis structures can be demonstrated by machine manufacturer, Eagle Laser. Eagle have used CompoTech’s carbon gantry for many years and are one of the first laser cutting companies to have taken a system first approach to using a carbon fibre traverse.
The lightweight nature of the moving parts provides maximum dynamic motion, whilst increasing stiffness ensures accurate cutting. Eagle has been able to take advantage of these improvements to double the peak acceleration, reaching the top speed faster and therefore reducing the cutting time. They recently released a 30kW laser cutter, claiming that the damping of the composite material manages the vibration at high speed.
Key benefits:
- The gantry weight is 44% lighter compared to a steel option
- Acceleration increased from 3g to 6g with a top speed of 350m/min
- 30% faster cutting time
- Stable temperature and vibration damping
Silicon Chip Inspection Gantry
SCHNEEBERGER develops positioning systems to produce silicon wafers. For quality assurance purposes, critical dimensions are regularly checked during the production process through wafer metrology. These measurements are used to verify dimensions of the order of <20 nanometers.
CompoTech developed a carbon axis using a double gantry system for the increase and speed of the wafer. The low mass system and high stiffness of the pitch fibre composite improved the dynamics to enable chip manufacturing units to achieve higher throughputs.
Acceleration up to 5g with positioning accuracy of 0.5 μm is achieved when installed in a semiconductor test system. If the user requires greater precision, the Twin Gantry can achieve positioning accuracies of 100-nanometers. Even then, acceleration speeds of 2gs are still possible.
