Interview How much measurement do you need on the shop floor?
Opinions vary on what die and mould makers require from metrology and quality control. Geoff McFarland, group engineering director at Renishaw, says toolmakers should use the latest measurement technologies to keep up with machining and other advancements.
ETMM: What are some of the most recent developments in measurement that can help die and mould producers?
Geoff McFarland: The much wider adoption of 5-axis machines in recent years has led to the development of a number of metrology products that enable manufacturers to fully benefit from the capabilities of the machines and to ensure that those machines are also functioning with operating parameters.
ETMM: What has the effect of this been?
McFarland: For example, with ever more complex free-form shapes, it is imperative that touch probe systems used to verify the dimensions of expensive moulds and dies both during and post machining cycles have a true 3D capability and also include robust methods for transmitting measurement data to the machine controller. To meet such requirements manufacturers can now source a wider range of probes that contain highly accurate strain gauge mechanisms which are able to handle data acquisition from complex 3D parts and also have the capability to carry long styli used to probe features deep within the tool without introducing measurement errors.
ETMM: Are there any additional changes?
McFarland: The other trend that we have seen is for tool manufacturers wanting to carry out inspection of the finished tool at the machine tool, rather than remove it to a co-ordinate measuring machine (CMM), especially where the tool is large. This also has the advantage of allowing adjustments to be made more easily to the tool should there be some tolerance issues.
ETMM: How has the industry responded to these shifts?
McFarland: Reacting to such challenges, metrology companies have introduced software that allows large volumes of data to be captured by probe systems on the machine tool and then for complex data analysis and subsequent part compensation to be carried out – Delcam’s Power Inspect and Renishaw’s OMV Pro software are examples of such products. The OMV Pro software incorporates advanced CMM style functionality including constructed features and geometric dimensioning and tolerancing (GD&T).