Nikon Metrology 3D laser scanning opens up new opportunitites for UK shop
Belgium – The combination of a laser scanner and co-ordinate measuring machine has proved to be the answer to the challenge a UK-based diecasting company was facing in bringing its products to market faster and reducing development costs.
At PMS Diecasting in Rotherham, UK, products are inspected by non-contact, 3D laser scanning to an accuracy of 2.5 µm, mirroring the precision of touch probing. According to Nikon Metrology, this has been made possible by the deployment of an LC15Dx laser scanner on an LK ceramic bridge co-ordinate measuring machine supplied by Nikon.
Widely regarded as one of Europe's leading and best equipped manufacturers of zinc castings, PMS has many high profile customers including returnable transit packaging specialist, Loadhog, window and door hardware supplier, Avocet, and wire joining and tensioning product manufacturer, Gripple, for which PMS makes 36 million castings annually.
The diecaster prides itself on using the most advanced technology and incorporates robotics wherever possible to streamline processes and make them more efficient and cost-effective. Automated part separation, quality control and management control systems are said to ensure consistent quality.
Measuring accuracy increased by an order of magnitude
"To avoid zinc flash forming at the parting line when a mould closes, the maximum allowable tolerance when machining the two die halves is ±10 µm," Gordon Panter, managing director of the employee-owned company, said. "Our optical profile projector and measuring microscope do not have the necessary resolution to inspect to this level of accuracy, but the Nikon equipment does."
"We considered both laser and white light scanning systems, but decided on the Nikon Metrology LC15Dx, as it was the only solution that could inspect our tooling to the accuracy we wanted," he said. The equipment is easily capable of inspecting tolerances of ±20 µm required on cast parts as well as features down to half that limit on the tooling that produces them, the company said. Freeform surfaces as well as geometry can be captured to the same high level of accuracy, 10 times better than previously possible at PMS. As a result, time-to-market for new products has been reduced and development costs are lower.
Combined use of laser scanning and touch probing
3D scanning is today the default inspection mode at PMS for freeform parts and standard features, while cores and other deep features are measured with a touch probe, which is also used to align components on the granite table prior to inspection. Either the laser scanner or a probe is mounted in a Renishaw PH10M motorised indexing head for maximum flexibility when programming measuring cycles using Nikon Metrology's multi-sensor Camio software platform.
Using Nikon Metrology Focus software, which manages the point clouds acquired during laser scanning, inspection data can be compared against the customer's original CAD model.
3D laser scanning has given rise to a further new PMS venture, that of providing a reverse engineering service for local firms. Highly accurate CAD files have already been produced for plastic injection moulders that did not have any digital data to work from.
Panter was surprised at how many enquiries he received after announcing the service on the PMS website and has decided to open a new reverse engineering division to expand this side of the growing business.