Carpenters rely on the maxim, “measure twice, cut once.” 3D printing / additive manufacturing (3DP/AM) lets users do essentially the same thing, ensuring product development is more cost effective and productive. For Hypro EU, a manufacturer of spray nozzles for agricultural and industrial applications in Cambridgeshire, UK, 3D printing has transformed product development. Thanks to prototyping with 3DP/AM, the designers know their designs will work before going into manufacturing production.
The development engineers there work closely with customers to fulfill specific, and often unique requirements. The engineers often use the latest additive technology for prototyping applications and to help with quality assurance. The additive manufacturing equipment they use includes a Perfactory 3D printing system from EnvisionTEC. This system is recognized as one of the most accurate machines for building 3D models and parts.
The Perfactory 3D printer was used in Hypro’s launch of its GuardianAIR Twin air inclusion nozzle. The Guardian AIR Twin is a crop spraying nozzle design that incorporates a new attachment concept. The patented attachment method is a twist ring that eliminates the traditional attachment method requiring separate caps.
This precision part required very tight tolerances and the capabilities, which the Perfactory successfully met. Trevor Swan, Principle Engineer at Hypro led the development of this product. Trevor, talking about the impact of the Perfactory at Hypro, said, “The Perfactory 3D printer has revolutionized the way we work because we can now produce single or multiple parts quickly and easily in production materials, which can be tested for suitability in the field. With the twist ring attachment part this was vital and would not have been possible without the Perfactory due to the highly accurate parts it produces first time off the machine.”
Before Hypro invested in AM technology the company’s designers sometimes overlooked features of the design that would fail in use due to extremes of pressure and temperature etc. Invariably the engineers had to commit to production tooling straight from the CAD model and could only field trial at this stage. If a problem with the design then became apparent, rectifying it was always a compromise because design changes were constrained to what was possible with the existing mold tool, which had already been purchased.
The twist ring, which consists of two separate parts that snap-fit together with mating teeth, was designed in Solidworks. The snap-fit of the parts required accurate tolerances and the Perfactory did not disappoint. Each part was 3D printed on the Perfactory and achieved a resolution of 16 microns first time off the machine.
From these original prototypes the rapid mold tool was formed using an aluminum filled two-part epoxy cast in a vacuum. The result was a perfect replication of the prototype parts that allowed 150 test parts to be produced for testing. Samples were assembled and tested in house for tooth engagement, deformation under a microscope and torque breakage force. With the production tooling for the test ring amounting to £36,000, it was essential that Hypro was able to establish that the product was exactly right before committing to this costly phase.
