What is in this article?:
- Modernizing Controls for Finishing Forgings
- Adaptive Control for Out-of-Round Hammer Forgings
A remanufactured three-stage lathe line gets a boost in productivity thanks to a state-of-the-art CNC concept
- Hard-surface machining
- CNCs, motors, and AC drives
- Rebuilt overhead gantry
Standard Forged Products chose Euro Machinery Specialists to remanufacture a three-stage machining line designed 50 years ago to finish rail and locomotive axles.
Adaptive Control for Out-of-Round Hammer Forgings
In Stage Two, the center section of the axle is machined with an overall first finish pass. Stage Three involves the final finish pass with a single headstock, 75-hp Simotics M-1PH8 motor driving the workpiece. In operation, while the customer spec for the axle surface finish is 250 RMS, the line is currently holding 124 RMS consistently, Engelke noted. Every workpiece in process is subject to form gage and profilometer readers for accuracy. Two semi-trailers full of chips are produced by this line, every day.
Each stage’s motion control is run by a Sinumerik 840D sl CNC, the Siemens flagship controller. An HT2 handheld unit is provided at each station for easy setup and commissioning.
Dual-channel (X, Z and U, W) cutting paths in Stage One necessitated a higher-level controller for accuracy, according to Cary Ramthun, CNC programmer and controls engineer at Euro. “We were challenged by the large amounts of power and torque required to perform this machining operation in each of the three stages,” Ramthun explained, “plus the overhead gantry system and other materials handling devices all required precise integration. We worked with Siemens to achieve the entire motion control and automation package. The movements are seamless and completely safe for both the customer’s operators and every component of the machine stages.”
Ramthun added: “Siemens programmers worked with us and Standard Forged Products programmers to accomplish the final solution on this project.” He called particular attention to the Siemens CNC’s adaptive control feature, which accommodates the out-of-roundness condition often found on hammer forgings. The Profinet coupler provided with the Sinumerik 840D sl syncs the gantry and the machine stages in a series of “handshakes,” with no hard-wiring, only sub-network connections are required, plus full isolation of the networks.
Engelke detailed the engineering required for the project presented considerable challenges, as well. “We were working with 1960s machinery built by a company that’s no longer in business. We started by reverse-engineering each individual machine component in our CAD system. Doing so allowed us to design, engineer, and adapt new modern mechanical and servo-driven solutions, as well as provide the customer with complete, highly detailed machine documentation, such as manuals with assembly drawings, spare parts lists, hydraulic, lubrication and electrical system schematics. Our customers find such documentation invaluable to their operations for service and troubleshooting of the machine tool.”
In addition to the Sinumerik CNC, Simatic HMI, and Simotics motors on the line, the 46-ft. long control cabinet features Sinamics booksize and chassis drives, active line modules, Sitop 24V DC power supplies and all auxiliary hardware for the machine and gantry control.
Euro Machinery Specialists was founded in 1969 by Engelke’s two grandfathers. Today, it operates several horizontal and vertical boring mill lines, machining centers plus grinding equipment — in addition to its rebuilding and retrofitting business. Customers range from major machine tool and construction equipment builders to the military and related contractors. The company employs over 20 people including two CNC engineers.
Engelke concludes, “This was a total team effort between Siemens, Standard Forged Products and our company. The result was a better-than-new production line for our customer, which came about through the use of new modern motion control and CNC technologies, diverse talents cooperating together and a good deal of old-fashioned American ingenuity.”