Laser Cutting Machines for Large Scale Applications

During its 25 years of being active in the segment of development and production of CNC machines for cutting materials with plasma, oxyfuel, laser and high pressure water jet, MicroStep has worked its way up among the renowned suppliers of these technologies on a global scale. This statement is proved by more than 2400 sold machines which are working in more than 50 countries all around the world and export representng approximately 90% of the production.

One of the key foci of the company is cutting materials using solid-state fiber laser. This technology is gradually starting to dominate the laser cutting market while the demand for CO2 lasers is continuing to drop. This is caused by a number of reasons the main of which are much higher energy efficiency, lower maintenance costs and longer service life.

Solid-state fiber lasers have brought new possibilities into the cutting market. Optic fiber has freed the cutting machine of the cumbersome reflective beam guide of the CO2 laser, which has considerably complicated the construction of machines. Size of such machines was limited, respectively large scale applications had to have the entire laser technology built on to the machine’s gantry, which drastically reduced its dynamics. Fiber lasers technology has opened up way for development and construction of more complicated cutting machines with feature not only laser cutting but also additional technologies increasing productivity of the machine. These can be the technologies for bevel cutting, drilling, tapping, countersinking, marking or even additional plasma cutting head. It is also much easier to design different customer oriented solutions, combine plate cutting with cutting of pipes, profiles etc.

Using these new options, the development in MicroStep has been focused on creating a modular structure for CNC machines, which would enable production of customer oriented systems in regard to the size of the working area and the type of installed technology. Based on this modular system different systems may be assembled beginning with the simple cutting machines MSF-Eco for cutting of workpieces with maximum size of 3 x 1.5 m. Then, there are the standard MSF laser cutters with a shuttle table and a maximum cutting area of 12 x 3 m and large MSF-Max systems which can have the working are of astonishing 50 x 6 m. MSF-Eco machines can be only equipped with a simple/basic straight cutting head and do not possess an automatic table exchange system. The standard MSF cutters are equipped with the automatic exchange system and may be equipped with bevel cutting laser tool station, drilling tool station with tool automatic tool exchange, line scanner tool station for scanning parts in case of additional beveling, etc. MSF-Max are constructed with permanent cutting table, which is divided into multiple cutting zones. A mobile safety cabin moves above the table. Within is the gantry with all the installed technologies. This type of machine allows for one or two beveling tool stations, drilling tool station with automatic tool exchange (up to 30 mm diameter), plasma beveling tool station, etc.
An example of such system is a laser CNC cutting system displayed in Fig. 1. Supplied in 2017 to the STX France shipyards, this is an unique 50 m long machine with two 21 x 3,5 m cutting zones. The working area consists of suction tables sunk into the ground of the production hall in order to allow easy access onto the grates during loading and unloading. The suction table is divided into zones controlled by pneumatic cylinders which open only the zones where the cutting is currently happening.


Fig. 1 Laser cutting machine MSF-Max with two cutting zones 21 x 3,5 m large

The gantry is moving above the cutting surface inside a mobile safety cabin which is always above the currently active cutting zone. Meanwhile the second cutting zone is being unloaded and subsequently loaded by the operators. The gantry may move only inside the safety cabin with the exception of maintenance when it may be moved a little outside the cabin as shown in Fig. 2


Fig. 2 Gantry of the cutting machine MSF-Max equipped with beveling laser tool station

The gantry moves on accurate linear guidelines which are separated from the cutting table. Covers on these guidelines protect them from damage which may be caused during manipulation with material above the machine. The safety cabin moves on separate guidelines and is driven by two-sided synchronized electric drive.
All the electronics are located in the rear part of the safety cabin in order for the length of all the electric cables, optical cables, cooling fluid lines, etc. to be minimal.



Fig. 3 Auto-calibration of Tool Geometry (ACTG) system located directly on the machine’s gantry.

Installed cutting technology on this machine is 8 kW fiber laser source from IPG. Transfer of the laser ray into the HIGHYAG cutting head is ensured by a fiber with a diameter of 150 micrometers. Kinematic structure of the cutting tool station allows its tilting in range of + 48o . This enables bevel cutting with a maximum angle of 45 o in the entire working area. The cutting system is able to create V, Y, K and X-cuts necessary for future welding of the cut parts. Accuracy and long-term stability of the machine is ensured by patented auto-calibration system (ACTG) developed by MicroStep. Because of the machine size it has been integrated together with calibration of the capacitive sensor on the cutting head and the nozzle cleaning and calibration station directly on the gantry. The unit may be seen in action in the Fig. 3. High absolute accuracy (approx. 0.2 mm) at a stable temperature has been ensured by path corrections calculated based on precise measurements done by a laser tracker.
The machine is controlled by the operator via an MMI console displayed in Fig. 4. It is mounted directly on the safety cabin and moves with it. Main display shows current machine information and the additional screen displays live feed from multiple cameras inside the cabin including the one on the cutting head. This allows the operator to monitor the cutting in real time.



Fig.4 The control console mounted on the mobile safety cabin

Thanks to focused development of solid-state fiber lasers, MicroStep is able to construct systems for even the most complex applications. This is a continuous development of course and MicroStep is constantly expanding its product portfolio by innovating the existing and developing new system modules.