One of the better applications of 3D printing is using it to perfect your design. You can get the first product out the door, then iterate as needed until perfect, or you can iterate to the perfect design, and then release the product. As Ryan Sybrant, Director of Manufacturing Channel Enablement at Stratasys, noted in a DesignWorldonline webinar, “We have to control our perfection tendencies, and simply do the best we can and then iterate like crazy.” (Recently we held a webinar on developing tooling with 3D printing. Sybrant was one of the presenters.)
“We see an overwhelming amount of interest in adopting this technology for uses other than prototyping, specifically in the production of manufacturing aids like jigs and fixtures and other miscellaneous tools,” noted Sybrant.
What you will find as you investigate 3D printing/additive manufacturing (3DP/AM) for jigs and fixtures is that you can instantly see results and take advantage of them. “When you adopt 3D printed tools into your everyday workflow, initially it feels as though you can take just a few steps, but then you find you are sprinting. It literally is like that proverbial light bulb going off,” said Sybrant.
Sybrant recommends asking the following questions when considering whether to use 3D printing for jigs and fixtures.
–Will it reduce scrap and rework?
–Will it decrease direct labor time or worker fatigue?
–Will it improve process throughput, control, repeatability, and so on?
–With respect to the bottom line, how much more profit would the company gain by making their overall processes more efficient?
An edge on efficiency
Jigs and fixtures can streamline production floor workflows. They can range from tool holders like 5S templates, to guides, to go/no-go gauges. They can also include sophisticated tools like robotic end-of-arm tools or end-effectors, sorters for conveyance, and transportation aids. The bottom line is that jigs and fixtures increase profit and efficiency while maintaining quality and improving operational efficiency.
The most important considerations in developing tooling are that they support accuracy, are easy to use, are economical to produce, and improve workforce safety.
3D printed tools can
–ensure interchangeability and part accuracy,
–improve functional performance of the production process,
–encourage complexity,
–reduce manufacturing time and cost,
–minimize human error,
–are usable by medium-skilled labor,
–allow production of repeat orders without tooling.
For manufacturers, 3D printed jigs and fixtures mean quicker machine setups, more repeatability during assembly and fit, and more secure part-holding operations.
3D printed jigs and fixtures enhance the “produceability” of parts and assemblies, reduce production costs, and improve quality and reliability. That’s how 3d printing can move up from the value chain from simple rapid prototype to functional testing to the middle of the value chain.
Traditional drawbacks
Users of traditional jigs and fixtures machined in metal are very familiar with a machine’s tolerances and variability. Traditional methods, however, often involve high costs, long lead times, increased weight, and storage issues. So, many manufacturers do without them, which reduces their ability to control their processes.
Fixtures made traditionally for inspection applications face similar issues. Oftentimes a team has to wait for the first versions of a product to come through the door before they can build fixtures for inspection. The result is delays of several weeks or more in the inspection process.
Other drawbacks include:
–Assembly variation, especially if significant rework is required to get the components or assemblies to spec.
–Increased part complexity when trying to produce the ideal holding fixture or drill jigs. Oftentimes this is when manufacturing personnel decide not to pursue these types of tools and find far less than ideal methods to get as close as they can.
–Tool size or weight, especially in transportation and handling, can become very problematic. These are the tools that may require lift assistance by a crane or extra precautionary measures to move from a storage location to production area.
–Worker fatigue, especially when performing repetitive physical actions.
If jigs and fixtures are deemed too costly or too complex to produce, often times they are not made, which can result in rework and production delays.
Said Sybrant, “I think about my days of designing jigs and fixtures. They were always made out of aluminum because we had access to that material. We had a history with it. We knew how it would survive the application. For people that have been in the industry a while, it can be hard for them to replace their current method.”
Designers of jigs and fixtures who use traditional manufacturing methods adhere to design for manufacturability rules because the rules were practical, and made lead times reasonable. But these rules don’t necessarily apply to 3D printing. The additive nature of the process gives unmatched freedom of design. What may have been impractical or even impossible is now realistic and reasonable. Design flexibility allows jigs and fixtures to have complex feature-laden configurations without adding time and cost, so there really is no penalty for complexity with additive.
The ability to design for ergonomics and reduce worker fatigue will improve overall process productivity. 3D printing lets you light-weight a tool by changing its part density. The technology is available today; the jigs and fixtures don’t have to be built solid. You can make a sparse or honeycombed interior that will keep the structural integrity of the parts but reduce weight.
The justification for additive is: it’s efficient. Jigs and fixtures made this way are low cost and quick to produce, which allows for more tools on the floor, translates into operational savings, and reduces burden rate. The challenge is to change design and common manufacturing mindsets. It will impact multiple departments.
Success stories
BMW has been a longtime user of additive manufacturing (AM) for rapid prototyping. But they soon realized the benefits of applying AM to other applications. One example is a badge or emblem assembly fixture. For its M Series vehicles, the engineers were able to remove several components that make up the fixture while removing weight and making it more ergonomic for the line workers.
Another example is a custom thumb brace that reduces worker fatigue during the repetitive process of pressing in grommets on the vehicles.
Wair Products saw the advantages offered by additive for the production of custom test fixtures for their line of respirators valves. Due to high product mix in the valves they offer, they needed a way to cost-effectively produce test fixtures quickly to meet production schedules. Prior to the additive fixtures, they were made of 15 machined aluminum components. This did not include the fasteners. Any time they machined the parts, it usually resulted in breaking into their production CNC equipment, which also affected their regular production schedule. By adopting AM, they were able to create the fixtures in 3 components versus 15. They were able to do it quickly and develop more worker-friendly fixtures by removing weight.
Genesis Systems Group, looked into using AM for its end-of-arm tools. One tool had embedded channels that could not be produced traditionally. By producing the tool with AM, they took a lot of weight out, which allowed the operators to grab parts quickly. The heavier that end-of-arm tool was, the slower they moved the arm around.
Leslie Langnau
llangnau@wtwhmedia.com
