X-ray experiments go remote
Technicians who perform R&D experiments with X-ray technologies may face both radiation danger and project slow-downs caused by having to shut down experiments during X-ray adjustments. To maximize safety and minimize wasted time in such studies, Oceaneering Space Systems (OSS) has developed a new micro-controller called u-Glide. "In applications such as X-ray crystallography, where a tiny, cryogenically frozen object held by a hair loop rotates around a center axis in an X-ray beam, the object under study may move in and out of the beam-requiring its position to be adjusted periodically. The u-Glide is a very small (13/8-inch- square, 5/8-inch-thick) two-axis positioning stage with a dedicated controller that lets technicians reposition the material being tested continuously and safely," says Bill Robertson, senior electrical engineer for OSS. The u-Glide travels approximate 6 mm in the x-y axis, with a resolution of 1 mm. "We think the unit has many potential applications," Robertson says, "and we'll introduce a three-axis version very soon." Oceaneering Space Systems: Enter 653
Low inertia gear reducers increase servo accuracy
A line of small, lightweight planetary gear reducers from Shimpo Drives promises more accurate motion control for small servo motors. New to U.S. markets, the Able Servo Planetary Gear Reducer works with six different motor capacities in a range from 0.5 to 5 kW and reduction ratios from 3:1 to 25:1 Backlash averages 0.7 down to 0.1 degrees or less, depending on frame size. Very compact, the gear reducer for 0.1-kW servo motors, for example, weighs 550g, and has an overall length of 99.5 mm. Toshi Onishi, vice president, says, "Servo motors are getting smaller and smaller for precise positioning. Smaller motors require lower inertia. These Able gear reducers are made for applications such as part feeders and robots." The planetary gear reducers are grease lubricated for any mounting position, and work with servo motors from all manufacturers. The new line also includes low backlash models. Shimpo Drives: Enter 654
Cool tool for hot spots
Now NMB Technologies' Tornado centrifugal blowers reportedly can address the problem of excessive processor heat in high pressure applications. "The faster the processor, the more heat it generates-and the more densely high-speed processors are packed in equipment such as servers and telecommunications equipment, the more the equipment needs targeted heat dissipation," says Robin White, program manager for fan products at NMB. The full line of Tornado blowers is targeted for high pressure applications where noise is not an important factor. NMB Technologies: Enter 655
Miniature actuators cause microscopic moves
Developed specifically for precision engineering applications in the semiconductor, medical, electronic, and metrology industries, a new line of miniature ball screw assemblies from Rexroth Star Linear initiates small movements for applications that require high precision. "Typical applications include handling devices for semiconductor wafers, inspection systems for wire-bonding, and reagent dispensing systems for the medical industry. Movements are very small and often require positioning within five microns," says Rick Bryant, application engineer for Star Linear miniature products. The ball screw assemblies average between 4 and 5 inches in length with diameters typically ranging from 6 to 12 mm. The amount of distance they travel per revolution of the screw depends on the size of the device. Fine leads allow small linear movements per rotation of the ballscrew. For example, lead wires for integrated chips measure only 30 microns, requiring movements of similar magnitude and accuracy when inspecting these bonds. "When you consider that a human hair measures only 50 microns, you can appreciate the precision of these devices," says Bryant. Rexroth Star Linear: Enter 656
Tiny motor powers tiny loads
At just 1.1 inch 2, Oriental Motors may have one of the smallest closed loop step motors available to power the ever-smaller machines employed in such high-tech applications as fiber-optic switches. The AlphaStep ASC34 AK is a two-phase step motor with a resolver to provide feedback on motor position. Its 24V dc motor driver is considerably larger than the motor itself. "Customers wanted a smaller motor for smaller machines with lower torque requirements, says Doug Rightmeir, applications engineer. "For example, fiber-optic switches sit under fiber-optic cables that may need fibers sent to between 40 and 45 different channels. The ASC34 motor powers reflective mirrors set on a turntable so that when light exits the fiber-optic cable, one mirror bounces the light beam-and all the data it's carrying-off the other mirror to select the channel for that fiber. The whole switch measures 1.5 to 2 inches in diameter or along the square. Additional applications include syringe pumps and small wafer handling in semiconductor manufacturing. "Customers in cost-conscious industries with requirements for very high precision-such as the biomedical industry-are showing a lot of interest in it," Rightmeir adds. Oriental Motors: Enter 657
High current gives motor high torque
By winding its SilverMax 34 frame motor for high current (16.5A, rather than the usual 10A) QuickSilver Controls' 34HC motor delivers 1400 inch-oz of torque in a seven-inch-long package that integrates the motor, controller, driver and an encoder for servo-style operation. "These motors use a new control technique called Position Velocity Integral Acceleration (PVIA), that can accommodate inertial mismatches of 100:1 and higher. PVIA also limits the integrator wind-up so that the integrator may only grow to a point that's still able to contribute to the output in a linear manner. This lets the system recover rapidly from a saturated condition with minimal overshoot," says Donald Labriola, president of QuickSilver Controls. The motor is set at 73A continuously, running at 125C. The driver runs nominally at 40A continuously, to produce 150% of motor rated current, also continuously. The integrated motor provides a 50-60% duty cycle, depending on temperature. Applications for the SilverMax 34HC include positioning bottles on conveyors. QuickSilver Controls: Enter 658