Reducing Time to Market Using CAM Systems
By Vivek Govekar
CAMWorks R&D Head
Traditional CAM systems are no longer suited to the fast-paced demands of the manufacturing industry and especially in the medical devices industry. The response time for delivering a medical device is critical. Efficiency and speed of delivery are of consequence in the quest of reducing the time to market.
The need of the hour is to actively apply tools and techniques that will cut decision-making time and automate activities from design prototyping to actual production and from order placement to actual delivery.
Medical Device Industry: Uncommon Challenges
We humans might be constructed in the same basic way, but we come in all sorts of sizes and shapes. Consequently, companies that are in the business of making parts and devices for people must produce a wide selection of sizes for each of their products. The dozens of versions of every bone prosthesis, knee caps, clamp, and other implants that they make demand that they choose between running small lots and carrying inventories—both of which add cost and pose their own challenges.
To complicate the task, precision, safety, quality and quick delivery are critical. Mistakes in this business can have dire consequences for patients, the end users.
Yet manufacturers of surgical instruments, medical devices and replacement body parts are not immune to market pressures. Like other manufacturers, they need to make their products faster and better while being economical. They are always looking for ways to streamline their design and manufacturing processes. They too need to keep their costs low, capabilities high, while maintaining a high degree of customer satisfaction.
Manufacturing of medical devices is a high-quality and high-precision business. This industry faces challenges that a typical machine shop doesn’t. Prototyping is the central aspect of their design process and operations, much more so than in most other types of manufacturing. The constant stream of new products entails the need for speed in getting their products to hospitals and doctors on a timely basis. Since each product device undergoes several iterations, such companies require CAM systems that can quickly accommodate those changes, update the toolpaths and change other affected machining parameters, and rapidly get the process going again.
This industry also caters to niche markets which require customizations to commercially available products to suit patient-specific requirements. This requires CAM systems with the capacity to automatically generate the toolpaths not only for the part currently being produced, but also for families of parts with similar features on new parts. For patient-specific medical devices, the safety, quality and on-time delivery of the device are critical factors.
Need of the Hour
CAM systems, which are intelligent and can acquire intelligence as per the industry-specific requirements, is the need of the hour. CAM systems need to have the potential to become an integral link in automated product manufacturing processes, from the receipt of the orders to the shipping, using resources globally. Such ability mandates that the CAM system have four key characteristics: Seamless integration between CAM and CAD applications; knowledge-based machining; feature-recognition technology; and application programming interfaces.
Advancement in the integration of the CAD/CAM systems can automate all aspects of manufacturing the parts including design, management, documentation and NC programming.
In most CAM software, the CAM data generated is saved separately from the CAD file. However, from a user perspective, keeping the data together in one single file makes for greater efficiency as chances of using mismatched code when work is resumed after a break are eliminated. Time-consuming file transfers can be eliminated by the use of integrated CAD/CAM systems that allow CAM data to be stored within the CAD part file.
Making CAM more intelligent: When solid modeling was introduced in CAD systems, more information became available from the model. Yet many CAM systems still do not capitalize on this extra information. Companies creating CAM systems must endeavor to leverage the CAD model to make CAM more intelligent and thus more useful to the end users. An intelligent CAM can thus make decisions which previously had to be decided by the personnel, resulting in greater levels of automation.
Associative machining: With tightly integrated CAD/CAM systems, any revision to the part designs updates the CAD solid model as well as the CAM file, allowing the CAM system to automatically generate the required new toolpaths, the tool list and, if it is necessary, the fixture/clamp modifications as well. This results in major time savings for manufacturing companies.
Parametric associativity: CAM systems with parametric associativity (all the relevant parameters are variables) enables users to change the value of each variable, allowing adjustment to size at any time after the NC program for a part is written. Consequently, it automatically updates the toolpath eliminating the need for NC programmers to redevelop the toolpath every time the geometry of the part changes.
Consider a spinal device such as vertebrae. Different sizes of the vertebrae need to be developed to suit individual requirements. The feature of parametric associativity will be quite useful to NC programmers.
Aiding Automation: Knowledge-Based CAM
As CAM systems continue to develop, there has been a growing trend towards Knowledge Based Machining (KBM). In a world where faster and economical production are critical, CAM systems that possess the ability to acquire intelligence using KBM can provide a competitive edge to manufacturers because they offer automation while still retaining control over the machining process.
CAM systems that incorporate KBM typically come with a generalized database of standard tools, preprogrammed speeds and feeds and information on standard material characteristics. These may also be supplemented by a set of predefined machining features and processes that can be tailored to preference. Such a system has the ability to recognize the machining features—and by using this data, the software automatically retrieves process and cutting conditions information from the database for cutting the part in the most effective way. Such pre‐definitions can help manufacturers considerably shorten programming cycles, especially for highly repeated machining processes. Pre-definitions which can be stored can include reusable features and attributes, operation sets, custom and standard tooling with feeds and speeds libraries, machine information, postprocessor information, and more.
Automatic Feature Recognition Technology (AFR)
In addition to automatically identifying regions to be machined, AFR should be able to suggest toolpaths based on different part geometries and must recognize features regardless of the CAD system used to create them.
When dealing with complex part models, the AFR’s ability to recognize more features in less time can result in major time savings since the time‐consuming process of manually identifying regions to be machined is eliminated.
KBM systems use this information generated by AFR to create operational plans, select appropriate tools and finally generate toolpaths. The combination of AFR and KBM provides increased flexibility and a high level of automation resulting in toolpath optimization and virtually automatic CNC programming.
Aiding Customization Capabilities: APIs
CAM systems must ideally provide a suite of Application Programming Interface (API) programs. Ability to adapt to suit industry-specific requirements is a key characteristic of an intelligent CAM system.
The addition of a wide variety of APIs, including one that helps interpret Product and Manufacturing Information (PMI) data, will help advanced users to automate a significant portion of their design-to-manufacture life cycle, reducing the drudgery of manual programming. This ability to automate can be harnessed fruitfully by the medical devices industry.
For example, consider a master model created for designing and manufacturing a particular medical device where multiple customizations are required. Template libraries and family tables for various types of the device can be created which can then be categorized. When an order is taken, it will be input into the job order system and then passed to the automated design/programming system. The automation rendered by the CAD and CAM APIs will create the design, regenerate toolpaths and output G-code, which will then be transferred to the shop floor.
The future of CAM systems holds great potential. Some of the key improvements to watch out for are reduced programming times, increased efficiency through greater levels of automation, auto-optimization of toolpaths for faster machining, highly and easily customizable KBM databases, consistent and predictable outputs.
This article was first published in the 2013 edition of the Medical Manufacturing Yearbook.
Published Date : 12/3/2013