Click Image to Enlarge
Negri Bossi's initial entry in injection molding robots is the servo-driven, four- and five-axis Flash S series.
The vast majority of new robots introduced at two recent trade shows were all-servo models tailored for speed and precision. One new model employs the latest linear servo technology in a cost-effective hybrid with standard servos on two of the three main axes. Also introduced at last fall's K 2001 show in Dusseldorf and Plastics USA in Chicago were servo/pneumatic hybrids designed for modest cost. Servo motors also showed up on the latest sprue pickers and versatile jointed-arm robots.
Serving up servos
At the high end of price and performance is the linear servo motor, which moves purely by electromagnetic induction. One of the first robot makers to use linear servos is Sytrama of Italy, represented here by sister company AEC/Automation Engineering, Windsor, Conn. Sytrama's new model RSV 102E3 is a hybrid of sorts: It achieves a balance of cost and performance by using a linear motor only on the telescoping Y (vertical) axis. Standard rotary servo motors drive the X (stripping) and Z (traverse) axes. The robot reportedly costs the same as a three-axis, all-servo unit of similar size, and only about 15% more than an all-pneumatic unit. Operating speeds range from 3.3 to 14.8 ft/sec, depending on the axis. Payload capacity is 17.6 lb. The line, suited for presses from 165 to 495 tons, also features a new teach pendant with touchscreen control and Windows software.
The Flash S series of four-axis servo robots marks the first entry in the robot arena from Negri Bossi of Italy and Concord, Ont. Four models with telescoping vertical arms serve presses from 160 to 1400 tons. Speeds are 6.4 to 9.6 ft/sec, depending on axis and model, and payload capacity is 22 or 33 lb. The electric cabinet is mounted on the robot beam to simplify wiring and save floor space. Wrist (C) axis has 90° rotation. For vertical presses, an optional B axis (rotation of the vertical arm) adds flexibility for palletizing.
EMI Plastic Equipment Inc., Wickliffe, Ohio, marked its entry into robots with several new servo and hybrid units from Wemo Automation AB of Sweden. One is the Model 55 servo-driven robot, with a telescoping arm and payload capacity of 22 lb. Operating speeds are from 9.6 to 16 ft/sec. Take-out time is 0.7 sec., while overall cycle time is estimated at 3.5 sec.
Wemo also came out with its first side-entry model, called the 14-5, designed for 40- to 50-ton presses. It carries a payload of 6.6 lb, and its take-out time is 0.37 sec.
The relatively new line of robots from Arburg (U.S. office in Newington, Conn.) was expanded with the new Multilift V top-entry, three-axis, all-servo unit designed to handle 55-lb payloads. It has an overhead structure that can be positioned either transverse or longitudinal to the machine axis. The robot is controlled and programmed through the machine's Selogica control.
Sepro of France (represented here by Conair in Pittsburgh) has a new five-axis model 3032 for presses of 500 tons and up. Sepro also said it would revamp its SR 4000 series this year with new controls.
The Austrian parent of Wittmann Robot & Automation Systems Inc., Torrington, Conn., has added new models to its Six series of servo units. The largest in the line is now the W673, with a payload capacity of 275 lb. Also new is the W625 H side-entry model, which moves at speeds up to 600 mm/sec. Demolding can be as fast as 0.83 sec and overall cycle time as short as 5.82 sec. Programming is said to be simplified by the addition of a new graphical editor to the controls' text editor.
Ranger Automation Systems, Inc., Shrewsbury, Mass., introduced a new addition to its Ultra Compact three-axis servo line, the model RT 1000 S3. A triple-telescoping arm accommodates low overheads (under 6 ft). Payload limit is about 75 lb.
Ranger also has a new RT-3000 series for presses of up to 8000 tons. It offers vertical stroke of 140 in. and traverse stroke to 500 in. Payload capacity ranges from 100 to 250 lb.
Hybrids for hire
If you want the speed and precision of a servo robot but without the price, a number of vendors think the solution is to use servo motors only where you need them. The new three-axis RX-51 robot from Remak North America, Erlanger, Ky., has a servo only on the Y axis, with pneumatic drives on the X and Z axes. The unit can handle payloads up to 22 lb, including the end-of-arm-tooling (EOAT). Suited to presses from 88 to 440 tons, the unit has strokes of 500 mm (X), 2500 mm (Y), and 2000 mm (Z).
Another robot with a single electric-driven axis is the Wemo Automation Model 8-5, available from EMI Plastic Equipment. It has pneumatic X and Y axes and electric Z axis. Described as a basic unit, is has simple controls and 1200-mm Y stroke.
Jointed arms advance
The new SV3X six-axis, jointed-arm robot from Motoman Inc., Dayton, Ohio, is designed for small-part assembly, machine tending, and materials handling. It can be integrated with a vision system for inspection and testing applications, too. The robot weighs less than 70 lb and has a reach of 26.7 in., repeatability of 0.001 in., and payload capacity of 6.6 lb.
Payloads up to 44.1 lb can be handled with Motoman's new UP20 six-axis model, which can be mounted on the floor, ceiling, or wall. The new model has 65.3-in. reach and repeatability to 0.002 in. A cutting device can be added to remove runners or sprues from injection molded parts.
Reis Machines Inc., Elgin Ill., offers a new small, six-axis, jointed arm robot called the RV4 that carries an 8.8-lb payload.
News in sprue pickers
Servo motors drive the new EC series MiniServo sprue picker from Geiger Handling USA Inc., Madison, Wis. Designed for machines of up to 330 tons, the new model has a payload limit of 3.3 lb (including the gripper) and a take-out time (fully loaded) of 1.4 sec, while total cycle time is 6 sec. Positioning is said to be accurate to ±1 mm.
The new RX11 picker from Remak is designed for presses from 22 to 440 tons and features take out time of 0.9 sec. Payload capacity is 2.2 lb. The unit has a 4.9-in. strip stroke and 180° range of pivot motion, which allows it to swing out of the way during mold changes.
The new SSR swiveling servo picker from Ranger Automation Systems Inc., Shrewsbury, Mass., acts like a T-beam robot due to its ability to swing 180° from one side to another without any mechanical changeover. The belt-driven, three-axis unit eliminates having to climb onto the machine to adjust the swing. It has a 36-in. strip stroke. Payload capacity is a robust 15 lb.
Set-up aid for EOAT
Processors who assemble their own end-of-arm tooling will find the job easier with the new generation of gripper-assembly supports from >ASS< Maschinenbau GmbH of Germany, represented here by ATS Automation Technology, Farmington Hills, Mich. The new supports are fixtures that hold both the plastic part to be gripped and the robot EOAT. Both are completely accessible from all sides, and the robot gripper can be set exactly by being brought into contact with the plastic part.