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Market Bosworth-based JJ Churchill is a family-owned precision engineering company that has expanded the engineering capabilities it provides customers in the aerospace, power generation and defense sectors. Key to this has been its use of the VERICUT independent NC verification software from CGTech.
JJ Churchill has been working closely with Rolls-Royce since 1937, and in 2009 the company was nominated for its customer’s prestigious Global Supplier of the Year Award, in the aerospace category, which it won. “This is not just recognition of what we have done,” says engineering manager, Jason Neville. “It is also recognition of our suppliers as well. Without certain key suppliers, including machine tools, consumable materials and of course software technology such as VERICUT, we could not have achieved the results we have.”
Originally the company’s business focused on spare parts and legacy aerofoil and blade engine components. However, during the past few years it has built on its blade knowledge in terms of what can be offered to its customers. As Jason Neville explains: “We used to solely supply Rolls-Royce in the early days, but market issues for the customer would greatly affect our business. So, over the years, we diversified and transferred our blade manufacturing expertise into different markets with different customers. These include Cummings high horsepower diesel engines for static and mobile power generation and off-highway vehicles, BAE systems for defence components and Siemens/Alstom high power generation.”
Having continually invested in the very latest 5-axis machine tool technology and systems to support unmanned machining to remain competitive at its traditional legacy stage of the customers’ product life cycle, JJ Churchill can now take its capability transfer a step further by offers its customers product development support and low volume manufacturing services. The manufacturing technology investment has also taken a further step with the company recently investing in a Makino Viper grinding machine, which will provide development and production grinding for hot or cold end engine components.
Depending on the volume required some legacy parts are produced from near net shape forged blanks while others are made from stock bar material. Usually all product development parts are produced from bar in the first instance, once the customer is happy that the aerofoil is right and testing is complete it will become a forging. Initially the flexibility of bar machining is required due to the time to market given to develop a new engine.
“At the development stage we use software that can talk to customers in whatever language they need. We use the Solidworks CAD package which we have had for many years as we design and manufacture all our own fixtures and workholding in-house. As a CAD system it is great for solids and prismatic shapes. We also have a seat of Unigraphics because our customer use it and we feel that it gives us certain benefits, it is slightly better for aerofoil surfaces,” states Jason Neville.
He continues: “How we program our machines depends on the business centre. If its advanced aerofoils, we have Starrag machine tools dedicated to blade making and these have their own CAM system – RCS – that creates tool paths from the solid model. For legacy parts, which are now probably going to be machined on a 5-axis machining centre, it can be as simple as programming at the machine’s controller or off-line in the engineering office. Our casting machining is not simultaneous 5-axis, its position and face mill/drill and we may then use our Edgecam CAM software to do that.
“Once you get past that stage the next part of the process is absolutely essential, the program has to go through VERICUT. We have multiple places where the program can be generated but the unifying thing is VERICUT’s independent checking of the tool path data. It has been so successful that it is company policy now – it’s not an option. With the NC code verified we have the confidence to run it on any of our machines.”
Today, setting times and component development times on the machines have been dramatically reduced, with the verified code going to the CNC system and cutting the part exactly to the model first time. The whole process is now so much quicker than it used to be, as it used to take about two weeks to create a development component, because of its complexity. With VERICUT in place JJ Churchill can now do this in around 2 hours.
All of the company’s advanced machines, such as the Starrags and the new Viper grinder have been modeled by CGTech, and all the engineering staff have been trained to use the VERICUT software. “When you look at how these machines move, the speed at which they move and the number of axes that are moving simultaneously, I would not want to stand at that machine if someone had hand programmed it. We operate three shifts and weekends, so the person who wrote the program may not be actually doing the proving out. These machines are incredibly quick and expensive so we have to make sure that everything is right. I had a comment from one of my engineers recently which says it all. He said we are due to prove a part on the 5-axis machine on Monday, but I can leave that with the shop floor because I know everything is fine. I ‘VERICUT it’ so I know exactly what to expect,” Jason Neville says.
As development work is carried out on the production machine tools the reduction in the time required has improved the business significantly. Taking any machine out of production for two or more weeks was the scenario faced by JJ Churchill prior to its improved engineering systems and reliance on VERICUT. Now the machine and human resources required for the development work are applied to the task for a few hours and then quickly reverted back to production. Jason Neville states: “We can support production and carry out development work effectively at the same time with the minimum of impact.”
Having started with a single seat of VERICUT two years ago, JJ Churchill now operates three. Originally the software was purchased as part of the company’s world class plan, which involved buying the best kit in class, without compromise, to return the lowest cost and the most effective blade development and manufacturing processes. Jason Neville presented an investment proposal plan which calculated the payback on the VERICUT software as about 2.6 years. “However”, he says, “we have done some very tricky stuff that we would never have delivered on time without VERICUT, just because of the complexity of the new components.”
Today, JJ Churchill is world class in terms of development lead times. Using it’s machined from bar process a set of blades for a ring will take between just 3 and 6 weeks, the traditional forging process requires 20 to 30 weeks.
Jason Neville concludes: “Everybody wants everything quicker – so we have to ensure that we have systems in place that provide that, including reducing lead times significantly thanks to VERICUT. With our world class goal we have been through a very big transition during the past two years, in the technology we are involved with and the software needed to manufacture blades from bar. To our business overall VERICUT has provided the biggest benefit.”