News

News from SmartDrive

Recent Press Releases and Editorials:-

Hear the Difference An editorial revealing the technology behind Taranis.

Stepping Up An editorial on SmartDrive's custom product developments.

Precision Motion System Produces Better Artificial Blood Vessel

Vascutek is one of the world’s leading designers, manufacturers and marketers of vascular products for the treatment of cardiovascular disease. Based at a custom built facility in Scotland, Vascutek uses innovative technologies to develop products that address the needs of cardiovascular and vascular surgeons throughout the world.

The company markets a wide range of polyester and ePTFE vascular prosthetic grafts for the treatment of diseased and damaged arteries. A new range of ePTFE replacement arteries was introduced last year, designed to offer a much thinner more flexible product but with enhanced physical properties.

The product is essentially a soft flexible tube, typically 8mm diameter, with a helical outer winding of a thin, narrow PTFE tape.

With the original production winding machines there were a number of issues relating to the inconsistency of set speeds of mandrel and dispensing carriage which required compensation, and also the tape itself varied slightly in width such that it was very difficult to produce a consistent finished product. Production was therefore very labour-intensive, requiring skilled operators to constantly monitor and adjust the speed of the linear carriage with respect to that of the mandrel.

Vascutek approached SmartDrive, Cambridgeshire-based manufacturers of precision stepper motor drives and controllers, to try to improve the production process. Together with their long-established partners, Hepco Motion, SmartDrive conceived, designed and built a custom mechanism and motion control system which incorporates digitally-interlocked speed setting on both axes, and also a non-contacting optical GaN LED micrometer which measures the tape width just before it is wound onto the mandrel. The data from this is polled over a serial port and the carriage speed is continuously adjusted to compensate for the all of the process variables.

Extensive pre-production trials were wholly successful, and two systems are now installed in Vascutek’s clean room, producing consistently high-quality artificial blood vessels at significantly higher yield than before.

Adobe Acrobat version of this news item.

The world's smallest hybrid stepper motors

The world's smallest hybrid stepper motors, measuring only 20mm square, are now available exclusively in the UK from SmartDrive. The ultracompact, lightweight motors, manufactured by Tamagawa, are available in two-phase (3692) and five-phase (3682) unipolar and bipolar versions, and combine high torque with high-speed response. The two-phase models offer 200 steps of 1.8 degrees each per revolution, whereas the five-phase versions offer 500 steps of 0.72 degrees, offering the possibility of 125,000 steps per revolution when used with the matched 250th-step Tamagawa microstepping drive.

Torque levels range from 0.013 to 0.032Nm for the two-phase and 0.013 to 0.024Nm for the five-phase versions.

Maximum pull-out torque is achieved at around 1000 pulses per second for the two-phase motors and up to 20,000 pulses per second for the five-phase models.

The motors are available with lengths of 30 and 46.5mm, with corresponding weights of 50 and 85g.

The catalogue for these products can be downloaded here.

SmartDrive Appointed as UK distributor for Tamagawa Motors and Encoders

SmartDrive, the Cambridgeshire based supplier of motion control solutions has been appointed as the exclusive UK distributor for the Motortronics® ranges of stepper motors, servo motors, resolvers and encoders from Japanese manufacturer Tamagawa.

Founded in 1938, Tamagawa is one of the world’s leading suppliers of precision motion control systems, and its products are widely used in industries as diverse as automotive, factory automation, scientific instrumentation and arcade games.
Commenting on the new agreement, Jon Bentley Business Development Manager of SmartDrive, said: ‘Tamagawa has a worldwide reputation for quality and reliability, and their products fit very well into our overall portfolio. When combined with SmartDrive’s own engineering expertise in the development of stepper and servo drive systems, they will enable us to offer a complete package of precision motion control solutions for a variety of industries.’

Pictured following the signing of the distributor agreement are Dennis Murphy (Left), Managing Director of SmartDrive and 'Mac' Masaki (Right), Overseas Sales Director of Tamagawa

An important feature of the Tamagawa approach is that the company is happy to produce ‘specials’ in relative small quantities – something that fits in very well with SmartDrive’s philosophy of producing complete motion-control solutions for customers in areas such as scientific equipment and laboratory instrumentation – where small production runs of relatively high value are typical.

‘The requirements of this relatively new – but expanding – market create new demands in terms of precision, accuracy and smoothness on motion control systems’, adds Jon Bentley: ‘and Tamagawa’s market leading resolvers and encoders are ideally suited to the requirements of this sector.’

Ultra-smooth DSP-based Stepper Drive in Eurocard Format

The new T-Series from SmartDrive is a unique Eurocard implementation of the company’s Taranis ultra-smooth DSP based microstepping drive/controller.
At the heart of the Taranis technology is a super-fast digital signal processor (DSP) with dedicated peripheral functions that enable direct precise control of the motor current switching devices.

The use of direct control, combined with adaptive mathematical modelling software, allows the winding current waveforms to be controlled very accurately, resulting in the elimination of most motor noise. In addition, it enables extremely smooth motion to be achieved, with over three million steps per revolution, as well as adapting to any motor nonlinearities.

This level of control makes the T- Series particularly attractive in scientific applications, where such fine control is desirable but until now has been largely unachievable.

The T-Series can be used in two fundamental modes: a step and direction slave mode which emulates a traditional microstepping drive and an intelligent controller/drive mode capable of self contained operation without the need for a separate signal generation source. Both implementations use a base microstepping resolution of 51,200 steps per revolution.

In slave mode, the T-Series Eurocard receives an external motion clock signal, but intelligently converts the input to ultra-smooth microstepping pulses. This feature ensures smoothness and reduced noise, even if the input source is operating at lower resolutions – with full- or half-stepping frequency, for example.

Using the full potential of the internal Texas Instruments DSP system, the intelligent Eurocard becomes a stand-alone combined drive and controller, supported by a 130-keyword BASIC language, flash memory, RS485 serial port and Windows-based development tools. By utilising the serial port in multi-drop mode it is possible to ‘daisy chain’ multiple Eurocards for multiple-axis applications.

Designed around advanced surface-mount technology, the compact (3U x 160mm Euromodule format) unit uses rugged MOSFET power stages and a compact high-efficiency heatsink to obtain continuous operation from the drive, with natural free-air convection cooling normally being sufficient. A standard module width of 9HP allows as many as eight drives plus a power supply to be housed in one 19-inch wide rack.

Winding current can be easily set to match the motor characteristics to the load while the motor is running, either by a rotary switch on the front panel or a resistor connected to the drive backplane. Five current ranges from 0.5A to 16.5A are available. In addition, the drive has a boost input which increases current output by 30%, a useful feature for providing rapid acceleration and one which can be used continuously.

A feature known as Comprehensive Dynamic Protection (CDP) monitors the drive’s dynamic environment and reacts within 5uS to protect the unit against all motor winding faults, including short-circuit to winding, short circuit to ground and low-inductance winding. In addition, there is protection against irregular motor supply voltage, low logic supply and over temperature conditions.

Reliability is ensured by the use of conservatively rated components combined with thorough production testing of all units under simulated fault conditions and for correct thermal performance.

Eurocard stepper drives offer up to 51,200 steps per revolution

Following recent rationalisation among other suppliers of stepper drives in Europe, SmartDrive’s DM Series is now the only microstepping drive from a major manufacturer available in the Eurocard format.

Designed for demanding applications requiring smooth precision motion, the DM range of microstepping drives offer exceptional performance, with up to 51,200 steps per revolution. Both binary and decimal resolutions are available.

Designed around advanced surface-mount ASIC technology, the compact units use rugged MOSFET power stages and a compact high-efficiency heatsink to obtain continuous operation from the Euromodule 3U × l60 mm format drive, with natural free air convection cooling normally being sufficient. A standard module width of 9HP (1.8 inch) allows as many as eight drives plus power supply to be housed in one 19-inch wide rack.

Winding current can be easily set to match the motor characteristics to the load while the motor is running, either by a rotary switch on the front panel or a resistor connected to the drive backplane. Five current ranges from 0.5 A to 16.5 A are available. In addition, the drive has a boost input which increases current output by 30%, a useful feature for providing rapid acceleration and one which can also be used continuously.

A feature known as comprehensive dynamic protection (CDP) monitors the drive’s dynamic environment and reacts within 5 µs to protect itself against all motor winding faults, including short-circuit to winding, short-circuit to ground and low-inductance winding. In addition, there is protection against irregular motor supply voltage, low logic supply and overtemperature conditions.

Reliability is ensured by the use of conservatively rated components combined with thorough production testing of all units under simulated fault conditions and for correct thermal performance. As a result, each DM drive provides a long life of trouble-free operation, even during adverse operating conditions.

For more information contatct SmartDrive Ltd on +44 (0) 1487 843663

'Slingshot' Roulette Wheel Uses SmartDrive's DSP Stepper Technology

Europe’s leading manufacturer of roulette wheels for casinos is using DSP-based stepper drive technology from Cambridgeshire-based SmartDrive as the basis of a new ‘slingshot’ technique for automating the operation of the wheel.

SmartDrive has worked closely with Cammegh Ltd. of Ashford, Kent, on all aspects of the project, from initial design through to manufacture. The result is a total mechatronic solution embracing areas as diverse as motor and gearbox selection, the wiring of sensors and software programming in addition to supplying the Taranis DSP combined controller/drive.

The need for automating roulette wheels is driven by a number of factors. The expansion of the gaming industry throughout the UK and Europe has resulted in a shortage of reliable croupiers who are prepared to work unsociable hours. There is also a trend to larger-scale casinos where multiple gaming consoles equipped with plasma screens and credit-card slots relay an image from a camera placed over a centrally located roulette wheel, opening the way for real-time online internet participation.

The situation is further complicated by legislation, which varies from country to country but can include limits on the maximum number of games per hour. With the SmartDrive solution, such parameters can be set via a communications protocol which is embedded into each controller and is available to each casino to address via a host device.

Cammegh developed the ‘slingshot’ approach because existing solutions for automating roulette wheels had limitations in performance, reliability and market acceptance. In particular, they wanted a system where the roulette ball was always in view - something that gamblers prefer – unlike earlier systems which involved the ball being loaded below the main wheel prior to emerging from a hole onto the rotating wheel

The logical approach was the slingshot technique, in which the ball, initially at rest in the centre of the wheel, is thrown to the edge by the wheel via a stepper-motor controlled acceleration. At the point when contact is made with the outer rim, it encounters a puff of air which accelerates the ball further. The duration of this puff of air is determined by a random number generator in the Taranis unit, and emulates the random effect that occurs when a traditional croupier slides the ball into the rotating wheel.

SmartDrive designed and developed not only the stepper drive system to control the wheel’s rotation but also all the associated proprietary interfaces and the software, including the serial protocols that link the wheel controls to the consoles and the host computer. The SmartDrive Taranis stepper unit not only provides enough power to drive the system reliably: its digital ultra-microstepping capability means that the resultant motion is smooth and quiet - something that is compatible with Cammegh’s reputation for quality and traditional craftsmanship.

‘This is a classic example of how sophisticated mechatronics technology can be applied to a traditional industry’, comments Dennis Murphy, Managing Director of SmartDrive: ‘It is particularly pleasing that two British manufacturers have been able to collaborate on a project like this, which has resulted in considerable export success.’

The end result is, according to Cammegh’s own promotional material, ‘the most accurate and reliable automatic roulette wheel platform on the market, combining a simple and elegant design with the build quality that is synonymous with Cammegh’.