Over the past 20 years additive manufacturing technology has migrated from use in rapid prototyping to a full-fledged manufacturing solution, which is referred to as additive manufacturing or direct digital manufacturing (DDM).
Increasingly, Australian companies are applying it to manufacturing applications, and with each success, they prove that it is a viable alternative.
For Sydney-based T R Savage & Son for instance, DDM offers an alternative to conventional metal-cutting manufacturing methods such as milling or turning, and the time savings are immense.
“There are virtually no delays in moving from a robust digital design to the manufacturing process,” Savage Design Director Joel Savage says.
“While it might have taken about a week to produce a jig in our machine shop in the past, the direct, uninterrupted progression from concept to part reduces the manufacturing time to as little as one day!”
While the general concept of additive manufacturing is the same as when it was introduced 20 years ago, the change is in its intended use: production, not just prototyping.
So while the concept has been around for a while, in the minds of many, direct digital manufacturing is a new thing and sometimes difficult to understand.
DDM is the process of using CAD or other data to drive an additive manufacturing machine that makes usable parts. Examples are the components that go into sellable products, pieces of production machinery, replacement parts, or manufacturing tools, such as jigs and fixtures.
Besides CAD data, which is the overwhelming majority of data used, other types of data may be used to drive additive manufacturing machines. Among others it includes 3D scan data (for reverse engineering) and DICOM data (for making a physical representation of 3D medical imagery).
DDM eliminates moulding, machining
Direct digital manufacturing eliminates moulding, machining, casting and forming. Instead of material removal or shaping, a company’s finished goods are produced by adding material one layer at a time.
Other than a few minutes of pre-processing to prepare a production run and some light post-processing to clean up a part, DDM progresses directly from CAD data to final part.
“Eliminating the up-front and back-end operations common to traditional methods means that there is no extraneous time, cost, or labour,” Tasman Machinery Managing Director Dermid McKinley explains.
“Replacing traditional machining methods with DDM offers increased efficiency, flexibility, responsiveness and affordability for our customers.
"DDM introduces fantastic alternatives in product design, manufacturing methodology and business operations, ultimately helping local manufacturing businesses to become more competitive.”
DDM offers unique and powerful advantages that distinguish it from traditional manufacturing methods. The most often cited are:
- Eliminate investment in tooling.
- Eliminate lag time between design and production.
- Eliminate design constraints.
- Eliminate penalty for redesign.
- Eliminate lot size minimums.
Green manufacturing, minimal waste
As an added benefit, many additive manufacturing technologies are fairly “green” processes. They have very little waste material as compared with milling processes because only the needed material is used.
No unnecessary inventory is produced because there is no benefit to building more than you need at any time. Most additive processes require no harmful chemicals and vent no harmful fumes into the environment.
Producing manufacturing tools and fixtures presents the ideal opportunity to try DDM. (Photo: Stratasys)
Among a list of other green benefits, is the relatively small amount of electricity that is required to produce parts via additive manufacturing.
“DDM essentially rewrites the rulebook for making manufacturing decisions,” McKinley adds. In many instances, it is a polar opposite to conventional production methods. This makes it a disruptive technology and makes it more difficult to appreciate and comprehend.
In the manufacturing environment, DDM often performs one of two roles. Companies will use the process to manufacture the products it sells or to make the devices that aid in the manufacturing of the products.
When first introduced to DDM most people envision the production of finished goods. The word manufacturing conjures images of high-volume production of consumer products.
People often jump to the definition ”the making of goods on a large scale,” even though manufacturing also means “the making or producing of anything.”
Low volume manufacturing, jigs and fixtures
“DDM is suited for low-volume manufacturing – not mass production,” McKinley explains and adds, “but before you think ‘We can’t use it because we do mass-production’, keep in mind every manufacturer has low-volume needs in the production of manufacturing tools, such as jigs, fixtures, gauges and hand tools.”
Producing manufacturing tools presents the ideal opportunity to try DDM. These tools are deployed to make manufacturing and assembly fast, efficient, repeatable and cost effective.
In this manufacturing context, DDM becomes a low-risk, high-return alternative to standard practices. Because the tools are used by the company, not the customer, and the time and cost to produce them is small, an unsuccessful attempt has little consequence.
But when successful, DDM has a major impact on productivity, quality and the cost of producing parts. Performing DDM of manufacturing tools is currently more popular than DDM for end-use parts. That’s partly because it’s such a low-risk opportunity, and partly because every manufacturer has a need for such tools.
Popular in many industries
Manufacturing can also be a bit of a misnomer when the entire spectrum of industries using DDM is considered. Some of the greatest successes are not in the manufacturing industry.
Because of the inherent need for custom fitting devices, the medical and dental professions have been early adopters of DDM. Orthotics, prosthetics, hearing aids and dental bridges have all benefitted from DDM.
Companies like T R Savage have discovered that DDM is a powerful alternative, rather than a direct replacement, to the conventional manufacturing processes.
DDM presents a nearly limitless range of opportunities. Companies have only begun to uncover all that it can do. It is exciting to realise that the scope of opportunities and potential is enormous. It is also good news that there are so many technologies and materials from which to choose.