La Roche sur Yon, France — Sepro Group has redesigned the prototype 5-axis robot (Success 22X) it demonstrated at the K 2019 trade fair and completed an update of the entire Success product line for injection molding machines from 20 to 700 tons.
Three of the units also can be optionally equipped with a 2-axis servo wrist — it was co-developed with Yaskawa Motoman — to create a 5-axis Cartesian design that Sepro says brings flexibility and economy to the market.
Sepro launched the Success range in 2011, billing it as the first truly affordable robot line to offer reliable, enhanced capabilities. Molders bought them for pick-and-place applications and simple downstream operations. The product line lived up to its name. Success became Sepro's best-selling robot family.
Sepro says the latest Success robots have an extended standard demolding stroke and, for the first time, a long-demolding (LD) configuration is available that can add 200mm to the stroke. Sepro says in some applications this allows certain-size robots to serve higher-tonnage molding machines than previously possible.
In some models, Sepro says the maximum horizontal stroke has been lengthened, and a telescoping vertical arm is available to extend that movement by as much as 200mm.
In addition, Sepro engineers have resumed use of cam follower bearings for linear motions of the new Success robots. Sepro developed and patented the bearings years ago to handle the heavy payloads and long strokes on large robots. The bearings are now standard on all Cartesian robots as recognized technology that not only improves weight distribution and operation compared to linear bearings, but also is more tolerant of dust and other contaminants.
Sepro says the three largest robots, which cover presses from 80 to 700 tons, are available in a 5-axis-servo 'X' configuration, which adds speed, flexibility and user-friendliness compared to 3-axis robots with pneumatic wrists.
The full-servo wrist on Success Line X robots is a feature previously found only on more technological robots, according to Claude Bernard, product marketing director.
"Among other advantages, the all-servo wrist can be easily adapted with simple digital commands, guaranteeing greater flexibility and faster production changeovers," Bernard said in a news release, adding that it approaches Single-Minute Exchange of Die (SMED) methodology. "We believe this represents the future of Cartesian robots."
Unlike pneumatic wrists, Sepro says servo motors have positional sensors that allow the robot to know exactly where the wrist — and gripper mounted to it — are positioned at all times. The robot can move in all 5 axes at any time to complete complicated motions, Sepro adds.
The company says it is becoming easier to extract a large, complex part with minimal clearance between mold halve or tie bars, or to position parts for secondary operations. At the same time, simpler end-of-arm tooling can be used because the servo wrist more easily compensates for minor misalignments, according to Sepro Group.
Many complex part-manipulation tasks required 6-axis articulated-arm robots. However, Sepro says the 5-axis Success X robots offer faster intervention into the mold space for shorter cycle times, while delivering the flexibility inside and outside the mold otherwise associated with an articulated unit.
Sepro also says set-up and operation are intuitive and the programming was designed to fit the unique needs of injection molding.