Hard tooling procurement is often a bottleneck in product development, but 3D printing provides a solution. Wells Engineered Products uses 3D printing to reduce the time needed to make prototypes for design validation and testing. Using this technology to speed up the design process lets engineers go through more design iterations and get a better product to market in less time.
Wells Engineered Products has used 3D printing in product development since 2013. Here’s a look at the technology and its limitations, how it’s used at Wells and the benefits it brings.
3D Printing Technology Primer
Processes for manufacturing metal objects are mostly subtractive. That is, metal is cut away from a large piece until the finished form is revealed. Like a sculptor carving a statue from a block of marble, it’s slow and inherently wasteful.
3D printing is an additive process. Objects are built by fusing material together. Plastics are ideal for this because it doesn’t take a lot of energy to bond them to themselves. Metals can be 3D printed although it takes a lot more energy. (Some might argue welding is a metal additive process.)
3D printing processes either deposit and fuse grains of powder or extrude material through a nozzle. Plastic objects can be printed by either method, but metals use deposition followed by fusing, typically done by scanning a laser over the surface.
Reasons for 3D Printing
3D printing turns CAD models into physical parts in a matter of hours. In contrast, if a part needs casting or molding it can take weeks to produce the tooling and days more to get parts off the machine or press. That’s the time during which development is essentially stalled.
By eliminating this delay 3D printing lets the development team forge ahead. They can look at the part from every angle and see how well it fits with mating parts or assemblies or whether it will go into the space available. While this can be done virtually in CAD most engineers agree there’s no substitute for having a physical part in the hand.
After assessing fit and form Engineering usually wants to move into testing. In some cases, it’s possible to test 3D printed parts but this depends on what they were made from. Many plastics used in 3D printing have glass transition temperatures (Tg) below those at which they need testing.
Limitations of 3D Printing
3D printing processes do not yet yield perfect, production/assembly-ready parts. There are three major limitations:
Printing processes depend on being able to deposit and fuse material. If the material needed for the design has a high melting point or cannot be extruded or fed in powder form it is probably not suitable for 3D printing. An alternative material can be used for fit and form evaluation but will have limited value in testing and will not be suitable for production.
Some 3D processes are more accurate than others. None has the accuracy of machining.
The objects that come off a 3D printer almost always need some finishing. This is for two reasons:
- To remove support structures needed to print overhanging regions. (Careful consideration of object orientation during printing can reduce the structures needed.)
- Most printing processes display visible layers on the sides. Sanding or grinding operation cleans them up to leave a smooth surface.
3D Printing at Wells Engineered Products
Engineers at Wells use 3D printing to produce:
- Prototype parts for design validation and testing
- Fixtures, grippers and other types of tooling for production
Many of the sensors, coils and other electronics that Wells manufactures are assembled into plastic enclosures or mounts. Others have plastic connectors or terminals. In production, these are molded, but that requires complex cavity tools that take a long time to make.
By eliminating the need for mold tools, 3D printing lets development teams get physical parts in less time. That lets them cycle through more iterations of the design, performing more evaluations and exploring more ideas. An additional benefit is that when production tooling is commissioned it needs fewer modifications – hopefully, none – to mold good parts.
Some testing of 3D printed parts is possible, but only within the limitations of the material. At Wells testing is done at up to 125⁰C (257⁰F): for printed parts to be tested they must be made from a material that remains rigid at this temperature. Only some 3D printing systems can process these higher Tg materials.
A second application area for 3D printing is tooling for test and production fixtures. Gripper fingers are one example of tooling that’s being 3D printed. While these plastic parts lack the durability of metal versions new pieces can be printed quickly and cheaply as needed.
This is particularly beneficial during testing and in low volume production. As with tooling for production parts, 3D printing reduces lead-times. That accelerates both product development and product launch.
3D Printing: A Future Production Technology?
Anyone who reads the manufacturing trade press knows there’s a lot of hype around 3D printing. To an extent, this is justified. 3D printing does enable the production of parts that cannot be made any other way.
For example, when coupled with “generative design,” it’s leading to organic-looking replacements for more traditional structures like brackets. By eliminating multiple manufacturing and assembly steps and reducing part weight this has obvious applications in aerospace and motorsport.
Other than highly specialized and high-value applications though, 3D printing is unlikely to replace conventional casting and molding processes any time soon. The barrier is primarily economic: these proven processes are fast and cost-effective. However, as metal 3D printing continues to advance this may find increased application in tooling manufacture.
Better Products in Less Time
Time to market is a key performance metric in many industries and it’s often constrained by delays in product development. 3D printing helps Wells Engineered Products move faster by eliminating hard tooling delays. It also leads to better performing products because there’s time to go through more iterations of the design. For these reasons, Wells is firmly committed to using this exciting new technology.