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Edgecam helps Dontaur’s machine shop soar

Based in Ballymena, just outside Belfast, Dontaur Engineering Ltd provides tightly toleranced machined components for a number of civil aircraft programmes. The company recently upgraded to the latest version of Edgecam - 2009 R1, having successfully used the software to offline program its CNC machine tools since the mid 80s.

When Dontaur Engineering Ltd moved to its current location in Ballymena in 1987 the company employed just 15 people. Today, thanks to its engineering capabilities and ongoing investment policies the company employs 59 highly skilled staff at it 50,000 ft2 facility. Its business is focused on contract machining aerospace components, which accounts for 90 per cent of its turnover, however the oil & gas and general commercial engineering sectors are also supported.

The machine shop deals with all the various ferrous and non ferrous aerospace alloys, airframe structural parts are aluminium and engine parts are predominantly HRSA (heat resistant super alloy) materials. Producing over 1500 individual parts for eight aircraft build programmes, batches run from 1-off up to 2000-off but 40 to 50 would be an average batch size produced to a just in time schedule. As the company’s NC programmer, Liam Gribben, explains: “The smaller the batch size the more efficient you have to be to keep the spindle cutting and reduce the set up times.”

He says the company was taking on parts that were ideally suited to 5-axis machining and producing them using surface machining in multiple operations with special form tools. However, during the past few years Dontaur has invested in 5-axis machining technology and currently operates two linear motor equipped Deckle Maho DMU50 eVo simultaneous 5-axis machining centres. This technology has provided a significant time saving for the company. For example, Liam Gribben says:  “A fuel nozzle receiver we produce has different angles across the whole part. This component was taking about 40 minutes to complete using our previous manufacturing methods. This has been reduced to just 11 minutes using our 5-axis capability.”

The DMG machines have been installed for around 18 months and the company has machined over 100 individual parts, with no part requiring more than two operations. Set up is much quicker as there are just two faces to fixture. The 3-axis VMCs on the shopfloor are required for longer parts and also for the heavy duty cutting of the steel aero engine mounting components.

All programming at Dontaur is done offline and as Liam Gribben points out “you need a powerful CAM package like Edgecam to support the 5-axis cell”. Two milling seats and a turning seat for programming the company’s lathes are used by Dontaur. The offline programming for the company’s lathes is more recent but the speed at which tool paths can be generated ensures the turning centres are running efficiently. “Some CAM systems will generate you a tool path but it might not be the one the engineer wants and there is little control over it,” Liam Gribben says. “Edgecam provides excellent flexibility for optimisation, to get the tool path to behave exactly how you want it to around the part. This is achieved with just a few clicks of the mouse.”

Also, he says most CAM providers write post processors for customers and there is no way to edit the post. “Edgecam’s code Wizard allows you to create your own post processor and it also has excellent editing functions so you can quickly modify or tweak a post from a similar machine. The code is also very reliable, which is vital because we don’t want to crash the spindle and face a situation where we could not supply the parts ordered by our customers.”

At Dontaur every program for both 5-axis machining centres is simulated using Edgecam to ensure the cutting cycle runs correctly, as the head/nutated table design of the machines creates complex programs. Edgecam’s machining simulation has effectively removed the need for traditional prove-outs of the NC code on the machine, making significant time savings. As well as the machine tool, the company uses Edgecam to simulate the tool holding and workholding to ensure the whole machine cycle is robust.

Aerospace work is predominantly Bombardier with some Boeing parts. Liam Gribben says: “Bombardier works in Catia as the native design package and supplies either Catia v4 surface models or Catia v5 solid models for us to work to. It was not stipulated that we had to operate Catia only that we had to be able to accurately read the model data. Edgecam is excellent for this as we can import the native Catia surface or solid model, which keeps the data correct to the designed part because it is not translated. It works from simple parts for the 2-axis lathes right up to complex 5-axis simultaneously machined items.”

As Edgecam licences the Catia modeling Kernel within its architecture it complies with these aerospace supply chain requirements without the need for companies, such as Dontaur, to actually have a seat of Catia on site. The ability to read the model is vital as any new projects from Bombardier are going to be paperless. All parts will be make-to-model and geometric tolerancing and product manufacturing information, so called functional tolerancing annotation (FTA), will be included within the Catia model.

Liam Gribben says: “Edgecam is also used for quoting new work and re-quoting existing projects as it is very quick at providing cycle times, and its material database includes speeds and feeds data for the different materials we use so the simulated cutting time is very accurate when compared to the actual production time required.”

Liam Gribben says Edgecam’s support has been first class. “Emailed queries are answered within a few hours and the staff on the telephone help desk are very knowledgeable. We can email them a component and the code for it, and they will work through what is happening and resolve any issues we have,” he says.

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