Torque motors are commonly used in indexing tables on machine tools. This succinct article helps you evaluate this and other applications in which power transmission for rotation calls for the advantages of a torque motor.
Torque motors simplify integration, offer high performance, reduce the cost of ownership and have an extensive working range.
The article was composed by Brian Zlotorzycki, a product specialist at ETEL, a Swiss designer and producer of components for direct drive technology. ETEL is part of Heidenhain, a supplier of machine tool CNCs, encoders, touch probes and other products for precise motion control and measurement.
In the same way that a computed tomography (CT) scanner at a hospital enables healthcare providers to “see” inside a patient, industrial CT scanning technology makes it possible to nondestructively measure and inspect the inside of a workpiece. The method works by passing an object (patient or part) between an X-ray-emitting tube and a sensor, generating a point cloud that is then interpreted with software to create 2D images or 3D models. A medical CT scanner rotates the X-ray emitter around the patient, whereas in industrial applications it’s typically the workpiece that moves, rotating slowly on a manipulator table while the sensor records data at set intervals. (For a brief overview of how the technology works, see this video on how a moldmaking firm uses CT scans.)
But apart from the different configurations of the CT scanner itself, scanning a metal part and obtaining precise measurements requires different capabilities than scanning a human patient. Metal parts have a greater tendency to absorb the X-rays, a characteristic which can introduce artifacts and affect the resolution of the generated image, especially when scanning denser workpieces. To maintain resolution on dense parts, industrial CT scanning systems must operate at higher kV power than medical scanners. GE’s Phoenix VTomeX M scanner, for example, is equipped with a 300-kV microfocus X-ray tube and a temperature-stabilized detector array. (A medical CT scan is typically conducted in the neighborhood of 70 to 140 kV.) The company says that these features enable the system to scan faster and achieve scanning accuracy down to 2 microns on parts ranging to 500 mm in diameter, 600 mm in height and weighing as much as 50 kg (110 lbs).
This ability to scan dense parts more quickly was a key draw for Exact Metrology, which recently installed a Phoenix VTomeX M CT scanner at its main facility in Cincinnati, Ohio. Using the Phoenix scanner, the company says it is able to generate a first article inspection report—including internal dimensions—in less than an hour, faster than using a tactile or optical CMM. Exact, which provides 3D scanning services in addition to metrology equipment, plans to use the CT scanner to offer process control as well as customer R&D services. Possible applications may include light metal castings, electronic assemblies, thermoplastic molded and composite parts, in addition to various machined metals.
A number of years ago, I visited National Jet in LaVale, Maryland to develop this article describing its micromachining and micro-drill-manufacturing capabilities. Recently, I happened to learn that the company’s founder, JA Cupler, appeared on the game show “I’ve Got a Secret” back in 1964. This video shows the clip, which is interesting to watch for nostalgia’s sake and the drilling demo. During the demo (this starts around time mark of 6:00 if you want to skip ahead), a National Jet machinist drills a hole through a strand of hair (about 0.003-inch in diameter) using a 0.001-inch diameter drill.
The Marcellus Shale Coalition.
The surge in shale gas production is not just a game changer for the energy industry, but also a major positive development for U.S. manufacturing. That is the message of a PricewaterhouseCoopers report that says the “shale effect,” the increase in U.S. natural gas production, is likely to achieve annual cost savings for U.S. manufacturers of $22.3 billion per year by 2030. Read more.
Data embedded in a 3D model will serve as a “digital thread” that unifies and integrates all manufacturing steps to save time and cut costs.
The National Institute of Standards and Technology (NIST) is initiating a project to demonstrate how a standardized 3D model of a product can integrate and streamline production from initial design through final inspection in a continuous, coherent data-driven process. With this project, NIST researchers and their industrial partners intended to develop what they see as a new dimension to manufacturing capabilities.
The project will demonstrate the feasibility—and benchmark the advantages—of using standardized, 3D models for electronically exchanging and processing product and manufacturing information all the way from design through inspection of the final part. This tightly integrated, seamless string of activities is what manufacturers are calling a “digital thread.” The project is aptly named the Design to Manufacturing and Inspection Project.
This approach contrasts with the common practice of converting 2D computer-aided design (CAD) drawings into static documents. The 3D models will be embedded with data and instructions that computers can interpret and apply to key manufacturing functions. According to NIST, this development will open the way to significant operational and bottom-line benefits. These include reduced cycle time and cost, less duplication of effort, lower risk of errors, increased part yields and higher-quality products.
Collaborators in the NIST-led project include International TechneGroup Incorporated (ITI), Milford, Ohio, and Advanced Collaboration Consulting Resources, Summerville, South Carolina, who are interoperability-focused manufacturing-services providers. Also participating are Rockwell Collins, an Iowa-based manufacturer of avionics and communication equipment for defense and commercial uses; and Geater Machining and Manufacturing, an aerospace supplier located in Independence, Iowa. Other participants are CNC Software, a Tolland, Connecticut, maker of computer-aided manufacturing (CAM) software; Mitutoyo America, a maker of measurement equipment and software; and software vendor CoreTechnologie, Rossford, Ohio.
The apparent catalyst for integrating this project is a new international standard for incorporating computer-readable product and manufacturing information (PMI) into 3D models. These models do not require human interpretation of graphical depictions followed by manual data reentry. Recently published by the international Organization for Standardization, ISO 10303-242 (also known as STEP AP 242) enables designers and process and systems engineers to embed 3D representations of parts with actionable specifications for materials, geometrical and dimensional tolerances, and surface texture, as well as process notes, finish requirements and other information
In the new project, Rockwell Collins will use its CAD system to generate a 3D design of a part, complete with all feature tolerances and other specifications. The design will be translated into STEP AP 242 so that Geater Machine and Manufacturing can repurpose the model into the language understood by the software it uses to generate machining instructions. Independently, Geater will reuse the STEP AP 242 model in software to generate code that will direct a coordinate measuring machine (CMM) to determine whether the part is manufactured as designed. The intent is to perform this step with no manual data entry. The project calls for researchers to verify and validate translations involved in the data exchanges at each stage in this thread.
The project will promote the implementation of data-driven manufacturing. “The various systems involved need to be autonomous, self-aware and self-correcting,” says NIST systems analyst Allison Barnard Feeney, leader of the project. “At the same time, they must be able to work harmoniously with human supervision and collaboration."
A full-scale demonstration of end-to-end interoperability is expected by summer 2015.