More and more companies are facing capacity problems due to a shortage of skilled welders.

This problem is also affecting Eastern European companies. BAST s.r.o., a large Czech supplier for the railway sector, has therefore decided to invest in robot welding. "This not only solves the problem caused by the lack of professional welders, but also improves the welding quality and the general efficiency of the production process", explains co-owner Miroslav Bazala. Valk Welding delivered two arc welding robots that are mounted on a gantry structure and serve three work stations over an 18 m track.

BAST manufactures cabin sections, doorframes and parts, frames, brake systems, coverings for air conditioning systems and switchboards, voltage converters, security components, battery compartments and other articles for rail vehicles. Its clients include well-known manufacturers such as Siemens, Alstom, Bombardier and Knorr-Bremse. Over 230 people work in two and or three shifts in a production area of 24,000 m2. For the processing of stainless steel and aluminium the company has an extensive CNC machinery plant for plate processing, welding and coating, in which MAG, MIG, TIG, laser welding and resistance spot welding are used.

2 Welding robots serving 3 work stations
"In the call for tenders in the spring of 2014 we chose Valk Welding as our robot integrator for their comprehensive knowledge and experience in the area of robot welding and their solutions for small series productions
that result in high productivity and profitability", explains Miroslav Bazala. Valk Welding delivered a comprehensive system consisting of two Panasonic TA-1900WGH3 welding robots mounted on a gantry structure serving 3 work stations. Both welding robots move on an 18-metre track for that purpose. The first work station, with a load capacity of 6,000 kg, is intended for single axis positioning and is therefore equipped with a positioner.
The center work station is equipped with a two-axis drop center positioner with a 1,500 kg load capacity. A third work station is equipped with an indextable with two positions and has a load capacity of 250 kg for smaller parts. The 3 work stations are set up in such a way that it is possible to position and process virtually all of the products and parts that BAST produces for the railroad sector.

Offline programming to reduce downtime
All of BAST's products are programmed offline so that small series can be processed as efficiently as possible on the welding robots. "Offline programming from a PC rather than directly on the robot maximises the productivity of the entire welding process. The downtime is considerably reduced because there is no need to interrupt production for programming”, explains Richard Mares of Valk Welding CZ s.r.o..

Arc-Eye laser tracking system
BAST supplies certified welding in conformity with EN 15085 and ISO 3834. To guarantee high welding quality BAST uses the Arc-Eye laser tracking system. The Arc-Eye system makes a complete 3D scan of the weld, detects any deviations and guides the welding robot exactly along the weld. "Also, the ARC-Eye laser sensor is not sensitive to reflections in glossy materials such as aluminium and stainless steel", explains Richard Mares.

What has been achieved with the robots?
"We have mainly made the switch to automation for small series and repeat orders for laser cutting, machining and welding. As well as the welding robots, we also have 2 laser welding robots", says Miroslav Bazala. "Robot automation not only replaces manual welding, but also helps us to raise overall productivity levels. About 80 percent of the welding is now done by the robots, which is equal to the work of 18-24 manual welders. This is how we have overcome the lack of welders and guaranteed the continuity of our production process." "It is also important for us to be able to fall back on service, training courses and support if programming issues arise. We're more than satisfied where that's concerned”, says Miroslav Bazala. "The Czech branch of Valk Welding has trained our people to a very high professional level." www.bast.cz