There are many types of tools available to the engineer to help produce the desired outcome for a given project. When designing a product, especially in the prototyping and experimental phases, two great systems help to facilitate success in a more streamlined fashion.
We use one of the many types of electronic computer-aided design (eCAD) and a type of part manufacturing known as subtractive or additive manufacturing.
Electronic computer-aided design is the process of designing products using software on a computer. It's used in both subtractive and additive manufacturing processes, but the way it's used is different, depending on a number of factors, such as materials, time and end results needed. There are a wide range of options in the eCAD world, and, depending on the level of sophistication involved with the eCAD program, we would expect a wide range of possibilities for the end product.
Certain types of CAD programs are intended for basic subtractive manufacturing processes only, while others are intended to support both additive and subtractive manufacturing.
Along with the wide range of options there is naturally a wide range of costs associated with the program chosen. There are low-cost online options available that utilize a subscription to give full access to the CAD and design tools, while other options require a substantial investment into the software and maintenance packages.
What was at one time termed “machining” has a new term added to differentiate between the two types of part manufacturing. Subtractive manufacturing is also becoming a major part of industry.
Subtractive manufacturing involves starting with a solid block of material and removing parts of it until the desired shape is achieved. Electronic computer-aided design is used to design the product, and the computer generates instructions, such as speed and feeds and toolpaths, for a machine to cut away the excess material.
This has been one of the major and most common ways of manufacturing any given part for many decades. At one time this was considered the only way to take a given piece of material and to shape it to create all the necessary features of the end product.
We have seen the advent of additive manufacturing, and we are learning of the benefits that it has for manufacturing. Additive manufacturing involves building up a product layer by layer from scratch. Electronic computer-aided design is used to design the product, and the computer generates instructions for a machine to add material in specific areas to build the product up layer by layer.
This can be powder deposition or melted-material deposition depending on the application. The bonding of the material happens in a number of ways, such as laser sintering and adding molten material in a controlled manner.
Unlike a casting, where molten liquid material is added to a predetermined mold or shape, additive manufacturing is able to build on itself layer by layer until the desired product is produced.
Typically there is a good amount of support material printed at the same time as the finished product material so that the part is self-supporting during the build process. The support material is designed in with the eCAD system and is made to easily break away after the final build.
In both cases, eCAD is used to create a digital design that can be turned into a physical product through manufacturing. The main difference is whether the process involves removing material—subtractive—or adding material—additive—to achieve the final product. To determine which type of software will work best for your type of product, it takes a solid understanding of what the critical success factors are for a given operation. Here are some questions to ask:
• Will we be constantly redesigning from prototype to finished product?
• Will the design be controlled by a single individual or by a wide team, and will we need to control iterations of the design?
• Does the design require traceability from the initial design to the finished product?
• Does the software provider also understand post processors and editing of post processors to assist and support the machines, whether additive or subtractive, for the manufacturing build of the part?
• How available are skilled designers and which software package are they most comfortable and familiar with?
Getting a great product starts with the ability to design that product in a way that best suits your manufacturing efforts. It is well worth the extra time and effort to research what type of software is going to work best when investing in new tools. The design phase is truly the tip of the spear and will have a long-lasting effect on the downstream efforts in manufacturing. Investing in eCAD systems prevents downstream failures, and the reward is realized when the end product is pulled off successfully over and over again.