The LK Altera M 30.15.10 at CMS Cepcor's manufacturing facility. (l-r) Ewan Laws, Apprentice Quality Inspector; Les Hickens, Quality Manager; Andrew Cliff, Senior Quality Engineer.
Ewan Laws, Apprentice Quality Inspector, inspecting a steel pinion shaft for a crusher.
In addition to inspecting its in-house manufactured components, as well as some high accuracy parts produced in CMS Cepcor's overseas factories, the company still undertakes legacy quality control of locomotive conrods. The one pictured is for the 70-year-old Duke of Gloucester, a British Rail Class 8 steam locomotive that has been recently overhauled.
PolyWorks Inspector software is used across all metrology platforms at CMS Cepcor-the LK CMM, two portable measuring arms and a robot-mounted optical scanner.
Founded in 1989 and headquartered in England, CMS Cepcor is a supplier of aftermarket crusher spares, manganese-steel wear liners and other equipment to the mining, aggregate production and associated industries worldwide. In 2024, the company took delivery of its first coordinate measuring machine (CMM), greatly enhancing quality control of the products it manufactures or refurbishes to tight tolerances. Having a nominal inspection volume of 3,000 mm x 1,500 mm x 1,000 mm, the CMM is an Altera M built by LK Metrology.
Previously, CMS Cepcor had been using a pair of manually-operated, portable 6-axis arms with a 2.5-meter and a 3-meter reach to check cast-iron, cast or forged steel and bronze components by touch-probing them. This was a lengthy process, as well as being insufficiently precise to measure some parts without difficulty. For example, it was challenging to inspect bearing seats whose tolerances are from 50 down to 30 microns total, shafts up to half a meter in diameter that need to be accurate to within 30 to 20 microns, and various features on housings that can be tied up to half that tolerance. Consequently, there was a need to use micrometers and other traditional manual gauges to measure those dimensions, which was even more time-consuming and subject to inconsistencies depending on which operator had been allocated the job. Additionally, some parts up to 400 mm in diameter by 700 mm long have eccentric tapers with drawing tolerances down to as little as 15 arcseconds, which were problematic to check by hand.
A further difficulty was that sometimes an arm would be set up on a metrology fixture table and in the process of measuring multiple items, such as head nuts or locking bolts produced in batches of up to 50, an urgent request would be made by shop floor staff for the arm to be transferred to a machine too