Drives & Controls Magazine May 2023

48 n SCIENTIFIC AND MEDICAL May 2023 Medical machine-builder turns to one-cable systems to cut costs The German machine-builder MA Micro Automation manufactures modular assembly, adjustment and testing systems for medical and visual inspection applications. Its machines are used to manufacture and test diagnostic consumables, medical injection-moulding components, insulin pens, auto injectors, and pipette tips – among other items. MA has two standard machine platforms – called Centauri IVD and Ceres POC – that it adapts to suit a project. “We aim to rely on standard modules wherever possible, and supplement these with specially developed individual components as required,”explains Dirk Striebel, the company’s head of operations. If neither of the platforms is suitable for an application, MA can produce custom machines. In one application, MA used the Centauri IVD platform to help meet the pandemic-related demand for pipette tips. These items – which are bulky, but require precision manufacturing – are used to draw precisely defined quantities of liquid and transfer them to test containers. The wall thicknesses and openings at the tip can measure a few tenths of a millimetre, and any discrepancy can affect the diagnostic result. “It is essential to watch out for issues such as burrs or deformations during the production process, and to eject any pipette tips with visible flaws,”Striebel explains. To help avoid such problems, MA integrates inspection stations into the production processes. To reduce injection-moulding machine downtime during round-the-clock operation, MA has integrated a buffer storage system between the machine and the downstream processes. “This offers enough capacity to cover 10 minutes, which is long enough to refill labels or filters as needed,” says Striebel. The faster cycle time of the system compared to the moulding process allows the buffer storage system to empty itself afterwards. With its Ceres POC platform, MA builds machines for rapid point-of-care (POC) diagnostics tests. The flexible production lines cover the entire process, from plastic moulding, to testing and packaging. Such machines can perform more than 30 million tests per year. On example of an MA custom machine is a flexible pipette-tip automation system with a high output rate, that it developed for a global supplier. The brief was to use flexible automation to allow pipette tips to be packed into racks for in-vitro diagnostics. The individual pipette tips had to be fed from bulk material with a cycle time of less than 0.1s, separated, and inserted into the racks, ready for packing. The injection moulds have up to 128 cavities, allowing various pipette tips to be produced. The pipettes are removed via an axis that can be adapted to the number of cavities in a few steps, making the removal axis scalable. A special handling strategy ensures that the pipette tips reach the racks after only a few automation steps, before being transported further using a linear transport system, such as Beckhoff’s XTS. Scalable automation For all of its machines, MA relies on PC-based controls – usually from Beckhoff, unless a customer requests a different control system. It also uses other items from the German automation supplier including servodrives, communications modules and control panels. MA has standardised on Beckhoff’s OCT (one-cable technology) to connect its drives, as well as EtherCat P (which carries power as well as signals) at the I/O level, and pre-assembled cables. Their use has cut its wiring work and improved decentralised power distribution using four-channel power distributors via EtherCat P. “These measures have significantly reduced our installation effort and the resulting costs by 15–20%,”Striebel reports. Another time-saver is OCA (one-cable automation), which avoids the need for up to 100 separate cables, which no longer have to be assembled, routed and placed into cabinets. This, in turn, reduces potential sources of error. I/O box modules and system lines can be coded using different colour rings. It is also possible to identify hybrid connectors through mechanical coding of the bayonet catches. According to Striebel, issues such as long cable lengths and resulting voltage drops “virtually take care of themselves with EtherCat P”. Similarly, using EtherCat box modules for power distribution allows different data concepts to be implemented, adapted or redesigned. MA is using the diagnostic functions of EtherCat and EtherCat P to simplify troubleshooting. Final assembly can be done largely without skilled electricians. “This is definitely the way things seem to be going in the world of 24V sensor/actuator installation,” Striebel suggests. He now wants to simplify assembly, disassembly and re-assembly: “The aim is to reduce cost-intensive activities at the customer’s site, and to shorten throughput times in the final assembly stage.” n A German OEM that specialises in machines for the medical sector has cut its cabling costs by up to 20% by turning to technologies such as “one-cable automation” and EtherCat P. With the high density of sensors and actuators in MA’s machines, cabling using hybrid cables and EtherCat P can save a lot of time.