Measuring those hard to reach spots

I think we’ve all dropped a remote behind a heavy couch or lost a pound in a car seat at some point in our lives. An inconvenience at most, but not enough of an issue to warrant a specialised tool or an engineered solution. In the field of manufacturing, that’s a different story. If something is impossible to reach with the available tools, that’s a clear obstacle in the manufacturing process that needs to be solved.

In the case of a component that was too large for the automated gauge used by Linex Manufacturing, the company went back to the supplier of the machine, Renishaw, and asked for a solution. Being experienced in the field of metal 3D printing, Renishaw offered a solution in a custom-printed titanium alloy gauge.

Linex Manufacturing is a division of the automotive part manufacturer Linamar Corporation that focuses on the production of automatic transmission components for commercial vehicles. Linex has been using Renishaw’s Equator 300 automated gauge system since 2015 in limited numbers, but an increase in production meant that from 2017, Linex required an increase in the number of automated gauges as well, going from two to six machines.

Renishaw’s Equator platform was able to positively impact the production process, although not without challenges. The Equator 300 has a diametric inspection volume of 300mm by 150mm high and is capable of accurately scanning components within temperatures ranging from five to fifty degrees Celsius at speeds exceeding 200mm/s, for components weighing up to 25kg. The main challenge for Linex arose when a component with 11mm bolt holes that lay just outside the working envelope of the Equator 300 needed to be scanned.

Narcis Georgescu, Senior Quality Supervisor at Linex Manufacturing, mentioned how “Precision was paramount, and they had to be inspected thoroughly” because the bolt holes were required for mating the front support assembly to another component.

To circumvent the issue, Linex first engineered their own solution, essentially increasing the reach of the Equator’s probe at an angle to improve its working range. However, as this was achieved by ways of constructing a separate tool from multiple components, Narcis Georgescu said “While it seemed to worked [sic] well, over time, it was causing an unexpected measurement uncertainty.”

Renishaw concluded that the necessary solution was to design a custom stylus that was not made of multiple components, as this would allow for too much flexibility. A 3D printed, metal stylus would be the way forward. And they delivered.

Designed in a CAD program, the Z-shaped, titanium alloy stylus, with an internal lattice work construction to save weight and increase accuracy, it was printed with powder bed fusion on a Renishaw RenAM 500Q. Using additive manufacturing, rather than more traditional processes, meant that Renishaw could quickly supply this custom component made entirely in one piece.

Narcis Georgescu said that because of the stylus’ solid design of just one piece, it “has enabled us to carry out full component inspections. It brings a combination of lightness and stiffness that we could not achieve.”

It has been several years since the custom solution to this challenge has been implemented, and Linex reports that the stylus shows no signs of degradation and is still performing within their expected accuracy and repeatability ranges. They have since purchased a second copy of the stylus and have also acquired one of the larger Equator 500 automated gauge systems.