3-axis robots taking on more complex tasks

March 9, 2017

Recent developments by suppliers are ensuring that the roles of three-axis robots will continue to expand in take-out operations, as well as in the performance of more complex automation tasks such as assembly and inspection. These smaller robots are undergoing metamorphoses in several areas, with the addition of controls technologies for Industry 4.0 and sensor technologies that are being combined for innovative solutions in molding plants. Here are the latest innovations.

WITTMAN BATTENFELD INC.

Wittmann Battenfeld Inc., Torrington, Conn., has announced the launch of its Primus 16 robot for pick-and-place applications that don't require complex automation. It is ideal for applications involving thin-walled components made by presses with clamping forces of 20 tons to 200 tons.

The robot has a stiff but lightweight vertical arm. It is available with a payload of up to about 11 pounds; a horizontal axis with a stroke of either about 59 inches or 79 inches; a vertical axis of 31 inches, 39 inches or 47 inches; and a demolding axis of either about 17 inches or 24 inches. With servomotors on all three axes, the robot moves smoothly with little noise.

Due to its modular design, the robot is cost-effective, the company says. The first model of a new series, it is designed to fill a niche for small robots. It's been adapted from the company's W818, which has a slightly bigger payload. Equipped with the company's R8 TeachBox control, the robot can be programmed in short sequences of steps — even by new users. Several control functions come standard: SmartRemoval reduces removal time, while EcoMode automatically sets the speed of travel.

SEPRO AMERICA LLC

Sepro America LLC, Warrendale, Pa., introduced the S5 sprue picker, a beam-mounted Cartesian robot with three servo-driven axes. The sprue picker is geared for simple automation of injection molding machines from 33 tons to 220 tons of clamping force. Its maximum payload is 2.2 pounds. Its horizontal stroke is about 24 inches with a demold stroke (transverse layout) of about 16 inches, and it has a vertical stroke of 39 inches.

The S5 comes standard with a simple sprue gripper but it can be supplied optionally with a rotating wrist and can be fitted with simple end-of-arm tooling. The standard picker operates entirely inside the injection molding machine footprint and includes an unloading chute and guarding. An optional extended-strip-stroke version is also available to evacuate sprues or small parts outside the molding press.

This sprue picker is equipped with Sepro's Touch Picker control system. The control systems on Sepro's products are becoming even more of a focus, said Jean-Michel Renaudeau, managing director of Sepro Robotique, in an interview during the K show. He emphasized that the growth of automation is just natural.

"To be innovative every year, this is the idea for Sepro," he said. "We are in industry, not only in 4.0. Ideas are great, but people need robots that are absolutely reliable. Any innovation that Sepro will do will be incremental. What are we going to do? We are going to offer as many niches as we can."

The Touch Picker control for the S5 is marketed as "what you see is what you get," that is, operators enter the parameters for the injection molding cycle by answering questions as prompted by the system and the operator is then able to see the result immediately in a 3-D video.

"We want to innovate every year, but we want to innovate for the needs of the customers," Renaudeau said. "So we pay attention at each and every show and every day to the needs of the customers, and then we do incremental innovation, and then we do exactly what they want. Industry 4.0 is very nice as a trend, but customers do not buy a trend; they buy a product. We want to be very pragmatic and very factual with them. So we offer them very factual products."

SAILOR AUTOMATION INC.

High speed is the focus of Sailor Automation Inc., Placentia, Calif. The company's RZ-A series of standard three- to five-axis robots has a take-out dry cycle time of less than 1 second and an overall dry cycle time of less than 6 seconds. The latest in the firm's Sigma series, the RZ Sigma-III, has a take-out dry cycle time of less than 0.8 second and an overall dry cycle time of 5 seconds. Satoshi Yamamuro, Sailor Automation's VP of sales, said that both types of robots feature rack-and-pinion linear actuators and precision linear guides that provide durability and vibration-resistance.

Yamamuro said Sailor Automation is developing two "ultra-fast" next-generation take-out robots that are scheduled to be introduced in the latter half of this year. One is a top-entry robot that will have a dry-cycle take-out time of 0.5 second. An ultra-fast side-entry robot is also under development, with an overall dry-cycle time of 5.5 seconds, he said.

CBW AUTOMATION INC.

CBW Automation Inc., Fort Collins, Colo., has developed two robots that feature small footprints, more flexibility and quick changeovers. At the K show, the company introduced the Advantage A robot, which uses a standardized base and frame for single-face molds, stack molds and in-mold labeling systems. The new Advantage A robot is modular, allowing it to be quickly adapted to new parts and minimizing downtime for changeovers. Standard features are strip-stroke part retrieval, electrical cabinets with segregated high- and low-voltage areas, remote connectivity via Ethernet, and for in-mold labeling, servo-controlled label placement.

The Beeline B robot, which has not yet been commercially introduced, has strip-stroke part retrieval, electrical cabinets with segregated high- and low-voltage areas and remote connectivity via Ethernet as standard features. The company said the Beeline B is flexible across a range of stack-mold center-section thicknesses and is able to create part stacks with a retrieval arm. The retrieval system operates on a three-axis, telescoping arm with the tooling attached to a "butterfly" rotation axis. This rotation system allows for the molded parts to be placed directly onto a conveyor with no hand-off.  With interchangeable carbon-fiber retrieval tooling, the Beeline B is able to adapt with minimum downtime to various mold arrays and products, according to the company.

WEMO AUTOMATION AB 

Wemo Automation AB, Värnamo, Sweden, which merged with Hahn Automation in 2015, has combined the companies' product lines to create a comprehensive offering that includes robot lines for complex automation tasks such as insert molding, high-speed applications for thin-wall parts and an economy line for simpler take-out applications.

Craig Tormoen, president of Robotic Automation Systems, Waunakee, Wis., is a systems integrator and distributor for Wemo. He notes that Wemo offers fixed X-axis (xDesign) robots and moveable X-axis (xLine) robots, both of which are designed for complex automation tasks. The xLine's moveable X-axis has a more compact footprint, especially for large parts in automotive applications, where it has been paired with injection presses of up to 5,500 tons. The advantage of offering both types of configurations is flexibility in the implementation, he said.

Olof Ståhl, director of technical management, said that the company has made an effort to reduce the weight and increase the stiffness of its robots. In the controls arena, Wemo offers Eco Function, which automatically adjusts the robot's movements to the actual cycle time of the injection molding machine. The result is significantly less energy use, smoother motion and less wear on the components.

ABSOLUTE ROBOT INC.

Three-axis Cartesian robots offer a nearly limitless number of features and configurations for users, said Bob Shingledecker, VP and GM of Absolute Robot Inc., Worcester, Mass., which distributes robots in the U.S. for Well-Lih, Ningbo, China, under its Absolute brand. Absolute Robot designs end-of-arm tooling in-house, Shingledecker said. One recent innovation is the use of fiber-optic sensors for part inspection in cases where space is limited. 'They give you a little more flexibility, because they have a small footprint and they are light," he says.

Shingledecker said that it is critical for a robot manufacturer to have an engineering team that can vet every application. "Every application that we have goes through our engineering department, and we require a size survey that takes into consideration things like overhead ceiling height," he says, adding that low ceiling heights are common in older manufacturing facilities in North America.

Among the trends he has seen is a demand for higher accuracy for molders performing in-mold labeling on small injection presses. In those cases, it is appropriate to use a robot with single-stage, rather than telescoping construction for the vertical axis. Also, rack-and-pinion linear actuation provides greater accuracy than belt-driven motion.

Absolute Robot drives operate on the CANopen Controller Area Network, which provides better device monitoring and communication, he said. Errors on a drive appear on the controller screen, rather than requiring the technician to open the control cabinet to locate the drive error. Another advantage is that the control incorporates vibration suppression software, which eliminates the need to manually tune the drives. In addition, circuit boards on the drives are treated with a conformal coating, a thin polymer film that protects the electronics from contamination.

HYROBOTICS CORP.

HYRobotics Corp., St. Louis, has developed sensing technologies that are offered as options on the company's three-axis take-out robots. The most recent is a weight-detection device known as Muge:in. This system was patented last year.  It joins two other quality-control systems, one focused on temperature of the molded part and the other on static removal. Both technologies have been available for about a year and a half, GM Sam Lee said.

The temperature device, called Temp:in, uses an infrared sensor on the robot arm that monitors the temperature of the mold surface for changes that would indicate inconsistent product quality resulting from potential problems inside the mold. The static-removal device, called Neut:in, uses an ionizer on the robot arm that removes static electricity from the part when the mold opens, preventing adhesion of dust on the part.

These technologies have potential applications for the automotive industry, and interest there is growing. For example, the anti-static technology could potentially eliminate a static removal step between molding and painting of automotive parts. All three technologies will be implemented at an automotive molder in Tennessee this year.

YUSHIN AMERICA INC.

Yushin America Inc., Cranston, R.I., recently partnered with medical parts molder Polymer Conversions Inc., Orchard Park, N.Y., on a part-inspection application. Tom Rybicki, Polymer Conversions manufacturing operations manager, said that Yushin integrated an existing leak-tester station and 300-ton Toyo Si injection press with a dual-arm servo robot, a pair of end-of-arm tools, a separation station and a complete safety enclosure. The Yushin YCII-250DS includes dual-vertical stroke telescopic arms, which allow shorter takeout time and low ceiling clearance.

As the mold opens, the sub-arm enters the mold and secures the parts with machined nests fitted with vacuum cups. The sub-arm then retracts and the mold closes. The main arm is positioned to permit its end-of-arm tool to grasp the eight parts. The main arm then pivots the end-of-arm tool and places the parts in the leak tester. After testing, the robot removes all parts, and good parts are placed in ejection chutes, and bad parts are released into a reject bin. One hundred percent of the parts are tested to ensure that the bad parts are separated from the good parts that are readied for shipment to the customer.

John DeGaspari, senior correspondent

[email protected]

Contact:

Absolute Robot Inc.,508-792-4305, www.absoluterobot.com 

CBW Automation, 970-229-9500, www.cbwautomatiopn.com 

HYRobotics Corp., 314-574-5777, www.hyrobotics.com 

Robotic Automation Systems, 800-937-9827, www.roboticautomationsystems.com

Sailor Automation Inc., 714-528-7711, www.sailorautomation.com 

Sepro America LLC, 412-459-0450, www.sepro-america.com 

Wittmann Battenfeld Inc., 860-496-9603, www.wittmann-group.com 

Yushin America Inc., 401-463-1800, www.yushinamerica.com