When a major customer comes to you with a component development that is set to revolutionise the market it’s time to call upon the skillset and reliability of your trusted suppliers for advice. This is exactly what a UK investment casting foundry did when a longstanding customer sought to push the boundaries with a complex and game-changing component that relies on the intricacies of investment casting to achieve the required surface finish and complexities.
Based in Kidderminster, Newby Foundries Investment Casting (NFIC) has a long history of meeting customer expectations and has further expanded its casting capabilities since becoming part of the Newby Group in 2015. The award-winning foundry produces high quality investment castings in a variety of ferrous and non-ferrous materials for a diverse customer base which includes petrochemical, automotive, lock and door, safety equipment and marine OEMs.
The company is experienced in working with customers to develop innovative components, but on this occasion, the requirements resulted in a re-think of the existing melting options. Much head scratching, collaborative thinking, problem solving discussions and trialling later and NFIC now houses what they believe to be the biggest investment casting rollover furnace ever made, thanks to Meltech Ltd.
Ian Calder of NFIC explains the rationale: “The customer wanted the part made as an investment casting as they were intrigued by the wall thicknesses we could achieve, we basically halved them. The weight reduction was matched with an improved surface finish, but constant customer adjustments meant it was a complex part with multiple small feeds and so was not suitable for ladle pour and would need to be made using a rollover. Also, the specification grew from 50kg to 70kg and we weren’t able to accommodate it with our 30kg furnaces.”
A rollover furnace gives a slower and more controlled fill. The gentle fill also enables air to be released from the mould. Initially NFIC tried rolling 40kg then ladle pouring the remainder, but they discovered this technique was fraught with complications.
Calder and the team at NFIC were also conscious that if they were to break boundaries with the new furnace, it would make sense to push for one that could handle not just 70kg but 100kg to allow for any future adaptations to the part or indeed to accommodate future complex components.
Up stepped Meltech with the challenge of creating the largest rollover they had ever produced that could cope with protecting the integrity of the shell during pouring and clamping. Steve Macey of Meltech explains the dilemma: “There were so many unknowns. Essentially it was a research and development project and we had to work fast. The job involves a big shell with lots of hot metal, rotating quickly. We also had to incorporate flexibility, servo mode, braking, controlled plc etc. It’s not just about building something large – it’s about ensuring that the weight and velocity of the metal and rotation doesn’t damage the shell during operation.”
Meltech also had to design around the crucible, which had to be a certain diameter. The company’s existing Mag-Melt induction rollover furnaces can be connected to all specifications of inverter systems and are built for demanding operations, so the technology is available, just not at the scale NFIC required. The ramp speed and rotation of the Meltech semi-automatic rollover furnaces already offer a very controlled and repeatable mould fill with less shell mould break outs than manual or hydraulic equivalents so the building blocks were there, but they needed to scale up for this project.
Within just a 14-week timescale, the new furnace was in-situ at NFIC’s Kidderminster base, housed in an interlocked and interfaced cage in a sand-filled pit to protect the wiring from any possible breakouts. Such is the size of the furnace, that it has been designed with the addition of a horizontal mode so that the crucible can be cleaned and the ingot added without the need to drop it from a great height, thus removing the possibility of cracking the crucible from the impact of the ingot.
Macey continues: “The control system has an infinite number of pour and rotation profiles and can be adjusted and stored on a menu. This was quite an undertaking, and we think it is the biggest rollover furnace ever made.”
The furnace is also equipped with the standard features of all Meltech rollover furnaces:
- Heavy gauge steel construction.
- Magnetically screened.
- Adjustable pneumatic driven clamps.
- Premium grade encoded servo motor and gearbox.
- Low resistance water cooled copper induction coil.
- Menu selectable ramp and rotation speeds.
- Fully interlocked to prevent accidental rolling.
- Desk mounted PLC control system and eight-inch touchscreen with simple to use menu-based functionality.
Calder is delighted with the outcome. “The results the customer has with the component are ground-breaking. The air to weight ratio and weight savings are enormous. The pour weight of the component is 65kg and the part weight is 25kg. It takes two weeks to make the shell, one hour to cast it and a long time to fettle all the risers off.”
This impressive example of R&D in the supply chain is even more remarkable considering that the 14-week development timescale and installation all happened during lockdown. A real success story for all concerned.
Macey says: “Meltech has been working with Newby Foundries for 22 years maintaining the existing equipment. This job at NFIC was bespoke, but we are small enough to be able to design something bespoke for a fast turnaround. We are also able to offer aftersales care to ensure everything runs smoothly.”
Teamwork, an open-minded approach, and a collaborative mindset saved the day and have highlighted that big things are possible with the right technology, the right people and the right attitude.
Meltech Ltd supplies a range of standard crucible and tilting furnaces along with Mag-Melt rollover furnaces.
The company manufactures electric induction furnace systems including power units and a variety of furnace bodies to suit all processes and casting methods. Pulsar IGBT Inverters offer induction furnace power supply between 75 to 750kW with frequencies of 200 to 10,000Hz for both air and vacuum melting applications.
Along with the cutting-edge new equipment, Meltech also have a long-standing reputation in the rebuilt furnace, service, and spares market for foundries throughout the UK and Europe.
Meltech Ltd, Tel: +44 (0) 1902 722588, email: [email protected] web: www.induction-furnaces.com
For more information and to view the machine in operation:
https://youtu.be/1eeoUdIPamA