The proper formula: CMM Inspection

Founded in 2011, British toolmaker and subcontract machining company GT Tooling Ltd. spent a year using conventional manual metrology equipment to measure the components it was milling and turning before investing in a 3D articulating arm, a six-axis model with a reach of 1.2 m (3.9′). Three years later, when the company moved from Petersfield to a bigger factory unit in Fareham, the company invested in a machining center with 1,651 mm × 762 mm × 762 mm (65″×30″×30″)
travels, which meant that larger prismatic parts had to be inspected in two operations.

The procedure was time-consuming and risked the introduction of errors due to the necessity for arm relocation. In May 2022, GT Tooling purchased a Freedom Classic Scan portable arm with a reach of 2 m (6.6′) from U.K.-headquartered LK Metrology Ltd. GT Tooling was introduced to this coordinate measuring machine manufacturer by nearby metrology tool supplier Mech Metrology & Power Tools, which also calibrates the toolmaker’s inspection equipment.

“We considered manually operated and CNC CMMs,” said Greg Simmonds, co-owner and director of GT Tooling. “However, the repeatability of measurement on the former was not good enough while the latter did not offer sufficient flexibility of use. Neither type had the reporting capability that was up to our standards or those of our customers. We also felt that programmable CMMs were better suited to series production because we machine mainly one-offs and small batches. As a result, we decided to stay with portable arm technology, but instead of returning to the incumbent supplier, we chose LK. We were keen to take advantage of the after-sales service for which they are known, and we also like the PolyWorks Inspector reporting software supplied as standard with LK Freedom arms. Simply by pulling out the required dimensions and pressing a button, reports can be manipulated freely into different, easily digestible formats to suit each customer’s preference.”

Ryan Leaves uses the Freedom Classic Scan portable arm at GT Tooling to inspect part of an aluminum extrusion blow mold for plastic bottle production. Image LK Metrology

The precision engineering firm supplies Formula One teams in the off-season. During that period, motor sports account for a large proportion of factory throughput, mainly the manufacture of patterns, jigs, fixtures and aluminum soft tools for producing composite race car parts.

“Greg and I witnessed a one-hour presentation on the Freedom arm by LK engineers in Castle Donington,” said Ryan Leaves, who doubles as a sales engineer and an inspector at GT Tooling. “It took place online during the pandemic. The demonstration, which included use of the PolyWorks software, was carried out inspecting one of our parts that had been taken away during a previous meeting in Fareham. It showed how easy the equipment is to use and left me feeling relaxed that, even though I do not have a formal metrology background, I would be able to implement the new inspection system quickly.”