"This is precisely what we need!" Roland Kuhz, owner of German metal engineering company Kuhz Metallbau, spontaneously stated at the product presentation of the Migatronic CoWelder. The CoWelder is a collaborative welding robot that combines the strengths of a welder with those of a machine, and is characterised by easy programming, intuitive operation and limited space requirements.
When Migatronic dealer SUT Rostock called attention to the CoWelder, Roland Kuhz was hooked immediately. Particularly for small companies with batch sizes from 20 to 300 units, the CoWelder is a flexible and affordable solution. After delivery and start-up by Migatronic and a half-day training course, the employees were able to produce the first components. As part of a two-day training course at Migatronic, two employees were trained in programming the CoWelder.
It is first and foremost the growth in the field of boat trailers which regularly leads to bottlenecks in the company’s production. Kuhz supplies boat trailers for motor boat, sailboats and inflatable boats from 570 to 2,870 kilogram payload. In terms of quality and the equipment of the trailers, the company sees itself at eye level with the well-known competitors in the market.
The processing time per component was 8 to 10 minutes. Today, the pure welding time is less than 5 minutes and the total processing time including the change process as well as preparation and post-treatment is just under 10 minutes for 3 components. In this way, it was possible to reduce the average processing time per component from 8-10 minutes to just over 3 minutes.
„Our motivation for automating the welding process is to prevent the shortage of skilled workers. The efficiency of the CoWelder allows us release work capacity for other tasks,“ Roland Kuhz explains about his reasons for purchasing the welding robot. The significant cost advantages resulting from the shorter production time are very much welcomed as spin-off.
Cowelder will do the same work for 700 hours
„The CoWelder has been in operation for 7 months now. We currently have an order in production, which earlier would not have been up for debate, viz. 1,200 welding positions on 600 components. Owing to the CoWelder, we dared to get on to the order. You know, it is hard to motivate an employee to do the same work for 700 hours. That is not a problem with the CoWelder,“ Roland Kuhz explains the positive development made possible by the new robot colleague.
For this order, socalled „eyes“ are produced for handling up to 300 tons heavy ship segments. 30 mm thick round plates are welded onto 30 mm thick steel plates. After welding a root pass, 4 additional welds are made on both sides of the component. This produces a total of approx. 10 m welded round seam on each component. If welded manually, the production time per component is 70 minutes. With the CoWelder, the process takes 30 minutes including the time needed to turn over the component. 30 tons of steel are processed for the production of the 600 components.
A welder would need around 700 hours, i.e. 17.5 man weeks for the production of the components. In co-operation with the CoWelder, however, the welder spends only a few minutes placing components in the fixture and turning them over. Most of the time, the welder can attend to other things.
Worth mentioning is the quality of the weld made by the CoWelder: since the CoWelder can weld the round seam fast and consistently in one process without interrupting the operation – which is not possible by hand - the quality is significantly better than manual welding. Add to this the continuity of the robot. „No matter if the CoWelder operates in day-shift or night-shift, it produces uniform quality. We would never demand that from an employee,“ Roland Kuhz explains.
A minimum of preparatory work
The preparatory work required to set up the CoWelder for this component was extremely manageable: creating the rather simple fixture took about half an hour. Creating welding programs took about 3 hours. Time well spent considering the large-scale savings in time and money.
In addition to the products mentioned, other trailer parts, such as gusset plates and roller supports are also being produced on the CoWelder. The robot has been fully utilised in full shift operation. Fixtures and programs for additional components are being prepared step by step in order to utilise the capacity of the CoWelder year-round by combining standard components and components from commissioned work. Seen over a total of around 15 different trailer components, Roland Kuhz calculates with approx. 40 per cent time saved. This means that 480 hours of manual welding result in approx. 270 CoWelder hours. Most of this time the welder can spend on other tasks.
"The CoWelder makes work easier. The investment has paid for itself – and we have no regrets,“ Roland Kuhz sums up the purchase of the CoWelder.