When engineers at Otterbox design a new style smart phone or smart tablet cover, they want the best possible prototype representation of the final product that they can achieve. They would prefer a prototype that is indistinguishable from the final product.
They get pretty close, but the challenge is creating nearly perfect prototypes quickly. The prototype finishers spend hours and days painstakingly masking off sections of the prototype phone and tablet covers and painting multiple colors onto them. In some cases, they must paint color lines that are less than 1/32 in. wide. And, like many engineers, the mantra of “get to market faster” is always rattling around in the mind.
Post processing steps, such as painting, polishing, assembly and others, have been a sticking point for many engineers that use 3D printing. Despite recent 3D printer introductions, this part of the prototyping process is still time intensive and the supplies expensive. For example, Brycen Smith, engineering technician supervisor for Otterbox, notes that he stores more than $100,000 of paint for prototype finishing.
Otterbox, though, has a new tool to speed up not only prototyping, but many other front end and back end 3D printing processes too. Last fall Otterbox became a beta site for a new 3D printing machine. This machine is different from others.
On the one hand, it is an evolutionary machine; instead of jetting three materials, it jets six base line materials. Like other members of this printer family, it jets materials with more than 300,000 Pantone-like colors and a range of Shore durometers. Plus, the build size is the same: 490 x 390 x 200 mm (19.3 x 15.35 x 7.9 in.).
The case for potentially revolutionary is this—every service bureau and many users have multiple 3D printers on site to handle different prototyping requirements and materials. What if you could use one printer to handle an even larger range of application needs, and nearly all of your post processing and assembly steps? What if you could eliminate CNC machine, sanding, silicone engraving, and text printing on parts with one system? Depending on the applications, such a system could remove 70% of your total development costs.
The new 3D printing machine is the just introduced Stratasys J750.
“We’ve used 3D printers for years but nothing has come close to revolutionizing our design and ideation process the way the Stratasys J750 has,” says Brycen Smith. “Stratasys allows us to innovate in ways we never thought possible and gives us the ability to create true product-matching prototypes and to cut down the time necessary to bring products to market.”
With the J750, Otterbox engineers can design and then print 5 to 8 iterative prototypes of a new case model in a day. Now, you might think the case design is simple. But Otterbox cases protect a number of highly sensitive areas on smart phones, areas that house sensors, antennas, and sensitive electronics for example. Plus, these cases must function so as not to impede a user’s ability to adjust volume buttons, block any of the plug-in ports, or block the camera lens. If you drop your phone on its edge, the case is specifically designed to protect these and others areas so that your phone will work when you pick it up off the floor.
Streamlining the creation process
The Stratasys J750 is an addition to the Objet Connex multi-color, multi-material series of 3D Printers. In addition to all the colors it will print, it also prints multiple material properties, ranging from rigid to flexible and opaque to transparent. Specific surface finishes range from matt to glossy, and features range from fine to large.
Several of the PolyJet 3D Printers jet multiple materials simultaneously so you can build an array of diverse properties in one job – and even create whole multi-material products in one piece, with little or no post-processing. The Connex3 and Stratasys J750 3D printers blend two or more materials to create composite Digital Materials with distinct, repeatable properties. Thus, you can combine rigid and rubber-like materials to simulate a range of Shore A values; mix multiple hues for full color capabilities; or blend rubber-like materials with color to create vibrant, flexible prototypes that look and feel like your future products. The J750 has four times the number of print heads of other PolyJet systems, and a smaller drop size. It has twice the print speed of other printers in its family, and delivers a layer resolution of 14 microns and accuracy of 0.1 mm, suitable for applications needing thin walls and complex geometries.
The J750’s support of a streamlined workflow begins with the new PolyJet Studio. With the software, you choose materials, optimize the build and manage print queues. Color, transparencies, Shore durometer levels and other features are loaded fully intact through VRML files imported from CAD tools.
Newly designed, state-of-the-art print heads mean simulated production plastics, like Digital ABS, can be printed in half the time of other Stratasys PolyJet systems. As 3D printed models are delivered complete with full colors, color textures and multiple materials, no time is wasted on painting and assembly.
Multi-jetting technology builds 3D objects by jetting fine droplets of photopolymers, which solidify when exposed to UV light. Although photopolymers are a different class of plastics than the thermoplastics and elastomers used in many production environments, they can simulate those materials mechanically, thermally and visually.
The key is always materials
Across the PolyJet 3D printer lineup, there are 22 base resins. Base resins are unblended material straight from the cartridge. They may be used alone or blended in pairs or trios to create composite Digital Materials. Pure base resins 3D printed in high-quality mode deliver a layer thickness of 14-16 microns, or about twice the width of a red blood cell. These resins are what give these printers’ such versatility in materials. You can combine multiple materials in a single part (multi-material 3D printing), and blend select base resins from the original 22 to create hybrid properties and colors. This capability is what is meant by 3D printing with Digital Materials.
The J750 printer simultaneously jets up to six materials from the portfolio of 22 base resins. Four Digital Materials simulate ABS, for example. All of the Digital ABS materials can be used for functional prototypes, including snap fits, and patterns, prototype tooling for injection molding and manufacturing aids such as jigs, fixtures and gauges. By blending rubber materials with Digital ABS or Rigid Opaque, the range of properties expands from soft touch with subtle color to those with a 10 Shore A hardness value ranging from 35 to 100. Counting the options for color, there are hundreds of digital material options for rubber.
Another beta customer of Stratasys, Synergy, used the J750 to speed up its decision making process for its consumer product designs.
Synergy is a product development company in Netanya, Israel. It produces whole-product prototypes in full color, even with multiple materials, textures and gradients, often in a few hours.
Before the Stratasys J750, Prototyping Manager Omer Gassner would have tapped several vendors to create a single keypad panel prototype: CNC machining and water printing for the body, casting for the light pipes, sanding for smoothness and then silicone engraving and additional printing for the buttons. It would have taken ten days to two weeks to create, at a cost of $700 per unit. With the Stratasys J750 it took just hours and cost $200 per unit.
The PolyJet 750 is a departure for Stratasys. The industry has been focused on building a printer for a specific function or capability. The PolyJet 750 is more of a “one-stop” machine. The goal is to eliminate the need to invest in multiple technologies to prototype parts.
Oh yeah, and it’s warranted, including the print heads.
Leslie Langnau
llangnau@wtwhmedia.com
