Pumping Out Prototypes

Among boat owners and builders the Whale brand has long been synonymous with marine pumps and their evocative model names, like Gusher, Gulper, and Orca. But there’s more to the company than just pumps. Whale now offers a range of engineering services, including product design, finite element analysis (FEA), software development, rapid prototyping, polymer molding, and testing. Its easy and cost-effective 3D printing can create real parts from 3D CAD files through additive manufacturing technology such as fused deposition modeling (FDM) or Polyjet and STEP computer files. Most of these services grew out of the company’s needs to design and prototype its own products.

whale-1Courtesy Munster Simms Ltd.

Rapid prototyping is done in-house at the Whale production facility with two Polyjet 3D printers.

Whale started in 1810 as the brand for marine pumps built by Munster Simms Engineering in Ireland. During the 1950s, Whale entered the marine leisure market with a line of manual bilge pumps named Gusher, which quickly gained a strong reputation for efficiency and reliability. Today, its marine systems include quick-connect plumbing, freshwater electric and manual pumps, faucets, showers, and filters, bilge pumps, gray-water and black-water toilet-waste pumps, cooktops, water heaters, and washdown pressure pumps and switches. Almost all are designed and manufactured in-house, and 70% are new products or have been reengineered in the last eight years. For that reason, the technology and polymer center is now at the heart of Whale’s strategy, with a workforce of 40 engineers and an annual budget of $2 million for R&D and manufacturing quality control.

Among today’s rapid prototyping options, Polyjet is the most advanced additive 3D manufacturing method. Its predecessor, FDM, was trademarked by Stratasys (Eden Prairie, Minnesota) in 1990 but is now in the public domain. FDM machines—the Whale production facility still employs an HP DesignJet 3D for building jigs and fixtures—make models by extruding through a hot nozzle a string of a molten material (usually ABS, polyamide, or polycarbonate) from a computer-controlled moving head along x- and y-axes. Successive layers replicate the third dimension, z, and the part’s volume.

While the resulting part provides visual details of the real model, its low mechanical properties (in part due to the restrictions of using only one material), poor finishing, and the practical difficulties of building overhangs are limitations.

The clear 3D printed body of this Watermaster pump design helped engineers visualize the internal fluid flow and test the computer model’s performance in the real world.Jean-Yves Poirier

The clear 3D printed body of this Watermaster pump design helped engineers visualize the internal fluid flow and test the computer model’s performance in the real world.

However, Polyjet technology, also trademarked by Stratasys, helped the 3D lab make a major breakthrough with Connex 350 and 500 machines. Instead of winding a molten thermoplastic, eight moving heads jet 16-micron-thick layers of instantly UV-cured liquid photopolymer droplets. A building tray slowly travels down the z-axis allowing fine layers to accumulate, creating the 3D model. Because Polyjet technology can use different materials or colors, it is easy to blend them in the same object, so parts can be different colors, opaque, clear, or tinted translucent; and combinations of rigid and rubber-like materials create watertightness, toughness, or resistance to high temperature. As many as 14 different materials can be mixed in a single part, and overhangs can be built with the help of temporary cradles or a removable gel-support material. A complex model can be made in less than 24 hours.

The Polyjet resolution is so high that the model’s surface is almost as good as a finished product, and Whale engineers can paint printed parts to match specified colors for exhibition-ready models. Rapid prototyping is practical and efficient for injection-molding tools compared to conventional technology, wherein any design mistake requires remaking the mold. Also, the tooling costs of conventional techniques, even in China, are high, so it is almost impossible to follow multiple design iterations before achieving ultimate design quality.

To solve this problem, engineers use Connex machines to create tooling prototypes with a digital Fullcure ABS (acryloni-trile butadiene styrene), which is tough and high-temperature–resistant enough to make initial injection trials and production runs. Polymer materials and injection technology are exactly the same as in production but come at a fraction of the cost of metal tools. A small series of up to 20 samples can then be made to test a mold tool design or to make alterations. This reduces the risk before laying down capital for full-production metal tooling.

Whale, 2 Enterprise Road, Bangor, Co. Down, Northern Ireland, BT19 7TA, tel. +44 (0) 28 9127 0531, website www.whalepumps.com.