W Hallam Castings’ foundry is at the core of its business, producing around 20,000 aluminium castings a week from 10 die-casting machines.

Established in 1968, the company produces parts for a wide range of applications, including air-conditioning systems, office furniture, DIY equipment, lighting and computer products.

It also carries out powder coating and assembly operations in-house to deliver a finished product to its customers.

The company was recently looking for a machining centre that could undertake extra operations on die-cast parts, such as drilling and threading; it also wanted a machine that was capable of manufacturing die-casting tools.

Operations manager Colin Woodruff selected a DMG Mori CMX 800 V (with a fourth-axis unit) from Coventry-based DMG Mori UK (www.dmgmori.com), as it has the flexibility to finish-machine castings and produce mould tools.

“We looked at machines that would have been a little faster for secondary machining operations on the die-cast parts, but they did not have the power and rigidity necessary to cut core and cavity features in H13 tool steel.

“During a demonstration, the DMG Mori machine achieved very high rates of metal removal as well as very fast rapid-traverse speeds, making it ideal for our application.”

Previously, W Hallam Castings sub-contracted its tooling, for which lead times were typically six to eight weeks. With the CMX 800 V, tools can now be completed in-house within two weeks — including heat treatment — and at significantly lower cost.

Mr Woodruff said: “We are adapting to a changing industry, where batch sizes are smaller. The CMX 800 V is opening up new possibilities and markets, as it allows us to be competitive through lower tooling costs and having the flexibility to make much smaller batch sizes — from 10 to 400.

“Moreover, the technology offered by the machine gives specific advantages in tool-making. For example, holes and NPT threads can be produced using circular interpolation; they are far more accurate than drilled holes, and the NPT threads deliver leak-proof connections for tool cooling.”

Detail design

W Hallam Castings uses its SolidWorks and CAMWorks CAD/CAM systems to consider details such as shrinkage, undercuts, venting and draft angles to ensure that parts can be manufactured.

The company also uses these systems for tool design and producing CNC programs for the CMX 800 V — plus designing and manufacturing fixtures for holding multiple parts on the machine’s fourth axis.

Mr Woodruff said: “As well as tool manufacture, we need to finish-machine features on the castings we produce.

The fourth-axis trunnion arrangement allows us to load multiple parts; cycle times are typically about 9min, and we can change fixtures for a new part in under 20min. We run the machine 24hr per day, and its speed allows us to finish about 550 sets of parts a week.

“To finish a casting can require as many as 13 different processes, such as drilling, tapping, milling, fitting Helicoil thread inserts and powder coating.

With the DMG Mori machine, most of these processes can be done in one operation, eliminating errors, reducing handling and labour content, and dramatically shortening lead times.”

Workforce development is important to W Hallam Castings, and the new DMG Mori machine has made a valuable contribution in this area.

The company has four apprentices studying at the Advanced Manufacturing Research Centre (AMRC), where DMG Mori is a Tier One member.

These apprentices include Adrian Salatowski, who won a Special Recognition Award at the AMRC Apprentice of the Year Awards 2017.

Mr Woodruff said: “The apprentices love the new machine. It has engendered a positive attitude among our employees, and the new technology we are deploying will enable us to attract even more highly skilled and motivated people.”