CNC is a technique for automating control of machine tools using software rooted in a microcomputer affixed to the tool. It is frequently used in manufacturing for machining metal and plastic parts.
John Cross, Micro
Data drive the accuracy and efficiency of the computerized numerical control (CNC) machines coming onto the market today. The latest CNC machines are equipped to collect data in real time as they run, and to control for factors such as thermal growth. The machines use algorithms to adjust themselves in a timely fashion to maintain accuracy.
To understand thermal growth, think back to your youth — specifically to that glass ketchup bottle with a metal cap that was too tight to remove. You may recall handing it to your mom, who went to the sink and ran the cap under hot water. Mysteriously, the cap came off easily after that. The science behind this home remedy is the fact that metal expands at a different rate than the glass when heated. The warmed cap eventually becomes larger than it was in its cold state, naturally releasing its grip on the bottle.
When cutting metal, CNC machines generate massive amounts of heat. Consider that these machines are made almost entirely of metal and think back to the bottle cap story. Imagine the expansion occurring with hundreds of metal parts bolted and welded together, 6 feet high and 8 feet wide. In this scenario, a part produced in a CNC when cold will be significantly different from a part made when the CNC comes up to operating temperature.
Not surprisingly, this sort of part-to-part variation is unacceptable to customers who require extremely tight tolerances, some down to as small as 5µm (compare this to a human hair which averages around 70 µm). It’s impossible to achieve this kind of dimensional capability on a CNC without using thermal compensation, achieved by actively collecting and continuously processing data.
CNC machines send temperature data into the algorithms running in the control unit. Once processed, the output is an on-the-fly modification of the machine’s actual position in space around the part being machined. Think of it as the part you want produced always staying in the same static spot in space, with the CNC machine continually morphing and resizing itself around it mathematically, ensuring every single part that comes out of the machine is the same.
Customers depend on trusted, innovative product development partners who are committed to improving and reinvesting in technology, equipment, state-of-the-art facilities and training. Here are three areas that are essential for success in CNC machining and other processes:
An experienced, full-service contract manufacturer that specializes in medical assembly, precision metal stamping, insert and injection molding, machining, sharpening, finishing and assembly can ensure delivery of the highest-quality products to customers. Selecting the right contract manufacturing partner with specific expertise can help customers design products that are optimized for production; the right partner can also help keep costs manageable and maximize return on investment.
Innovation and technology advances
Customers who want CNC-enabled products and want help with product development and design need partners who can excel in prototyping and validation to full-scale production. They also expect the highest standards of patient safety, product performance, customer service and regulatory compliance, no matter what technology or method is used for production.
For CNC projects to succeed, collaboration should start early in the design phase. This uses the manufacturer’s expertise and minimizes the risk of having to undergo multiple design iterations, which are costly and time-consuming.
Developing an efficient design is crucial to keeping costs manageable and return on investment high. This is especially true for components and devices that require sophisticated features, precision parts and intricate designs, such as articulating instruments and tight tolerances as described for CNC. Close collaboration with customers is vital to understanding device function and improving processes while maintaining performance, allowing customers to deliver new and improved medical technology solutions in an increasingly cost-sensitive marketplace.
John Cross is senior manager of research & development for Micro, leading the development, technical oversight and execution of new manufacturing platforms, technologies and processes. He is responsible for the full range of development from prototyping to operational transfer.
The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of Medical Design and Outsourcing or its employees.