VERICUT provides a harvest of benefits for John Deere
As one of the leading forestry and agricultural machinery manufacturers, John Deere faces challenges from global competition, and a company commitment to always deliver machinery to its customers on time. CGTech’s CNC machine tool simulation, verification and optimisation software, VERICUT, is providing manufacturing process integrity and improving efficiency at the company’s manufacturing facility in Finland, and is also delivering a common software platform for John Deere’s facilities around the world.
With production facilities in 16 different countries and employing more than 50,000 people, John Deere’s forestry, agricultural and earthmoving products are instantly recognisable in their green and yellow livery. At its Joensuu factory the company employs around 400 staff, manufacturing all forwarders, wheeled harvesters, slash bundlers, harvesting heads and cranes. The other forestry products in the extensive range are produced in Iowa, USA. With an established network of distributors supplying forestry machinery to customers in over 35 countries, including Sweden, Russia, South America and the UK.
Product development for the cut-to-length machinery takes place at its Tampere facility. Here, 250 staff provides research, development and design support, as well as administration services. The whole company’s R&D spend is a staggering $4.8 million per day.
The Joensuu facility was originally established in 1972, and forestry machinery was built in batches for stock before it was sold. More recently, a change in manufacturing methods was instigated with a factory master production plan, which included enterprise wide planning provided by SAP.
Today, the highly advanced customer-specific machinery is made-to-order on a constantly moving production line, enabling punctual delivery of the machinery within 40 days of order. Capacity and productivity are vital parts of the factory master plan to achieve reliable delivery of hundreds of units per year, and the company has invested heavily in its machining cell.
Two highly efficient twin-machine FPT machining cells with automated pallet loading are used to produce the structural parts of the products. The ram spindles of each of the FPT machines face each other, allowing both machines to cut the component loaded in the working envelope. However, this was a concern for the company as any collision between the machine’s structure and the component or fixturing would result in a significant loss of production capacity, hampering the daily build target of the forestry machines.
When the first twin-machine cell was installed the company purchased Pro/Engineer CAD/CAM software to program the twin 3+2 axis machines offline. “The CAD model is created in Pro/Engineer and the software’s Manufacturing module provides the CAM NC program file, which is post processed for the machining cell. While the Manufacturing module allows me to simulate the tool path, it does not show me if there is a crash,” explains CAD/CAM Engineer Jouni Porkka.
As the two machines face each other and are capable of cutting simultaneously, working together on the component being machined, the two NC systems are linked by a PLC. However, there was no trust from the operators and they would simply operate one machine and then the other, significantly extending the planned machining cycle times and not achieving the efficiency gains.
John Deere found the answer to its problem with the installation of full 5-axis VERICUT software, to simulate the twin 3+2 machining capability of the cell. The software is supplied and supported in Finland by Pathtrace Oy. As Jouni Porkka recalls: “All of the modelled elements from Pro/Engineer are imported into VERICUT, including the raw material, fixturing, cutting tools and holders, machine structures and the swing arm tool changer, which has to be positioned correctly not to collide with any other element during the tool changing process. Even the long tools we use to allow complete access to the component have been accurately modelled.
“And, from the NC data we have checked so far, there would have been a significant number of machine collisions if we had run the NC program without checking it with VERICUT.”
Once the design of the product component, such as the welded chassis, has been finalised any further modifications are few and far between. So, when the process has been verified in VERICUT the file is considered safe to use for production. The VERICUT NC file is pulled down to the machining cell from the company’s network, and if any modifications are required they are done by Jouni Porkka. No changes are made at the CNC system.
A total of more than 40 different components will be machined by the FPT cell. With this quantity of components additional programming support has been provided by John Deere staff in India, where the company also uses VERICUT to check the finished NC program. The Indian facility also has a complete VERICUT model of the twin-machine FPT cell, including the fixturing and tooling assemblies.
To help shorten the implementation time fixturing is being manufactured in Czech Republic by a precision engineering company from the designs completed in India, so VERICUT is the common software platform supporting the truly global nature of John Deere’s business model.
The factory plan sees the removal of the older machining cell when the new pallet system is installed and all the parts programs have been proven safe by VERICUT. The longest cycle time on for a component in the FPT cell is around 3 hours, machining bearing locations and mating surfaces, as well as drilling and tapping multiple points for assembly. The equivalent part’s cycle time was over 6 hours on the previous machining cell, so significant savings are being achieved.
Jouni Porkka concludes: “First stage of our continuous improvement engineering philosophy is to make everything in production safe, and VERICUT has achieved that for us. We have to save the machine spindles and eliminate lost production time, fortunately it is safe to crash in VERICUT and NC programs can be modified without any serious consequence.”
Article published in PES, October 2013 [PDF]