Edge CAM provides vital machining link to Pro-ENGINEER design system at IPE

Citation

(2002), "Edge CAM provides vital machining link to Pro-ENGINEER design system at IPE", Aircraft Engineering and Aerospace Technology, Vol. 74 No. 5. https://doi.org/10.1108/aeat.2002.12774eab.001

Edge CAM provides vital machining link to Pro-ENGINEER design system at IPE

Keywords: Machining, Aerospace, Components, CADCAM

Aerospace component manufacturer IPE is said to be reaping the rewards of upgrading its computer-aided design and manufacturing software capability by linking the Pro-ENGINEER solid modelling package with Path trace's Edge CAM off-line programming system. In particular, the company is gaining all-round productivity benefits from the systems ability to seamlessly integrate with each other and to provide a "universal" answer to all its design and CNN machining needs (Plate 1).

Even though the company had been a long-term user of Path trace CNN programming systems, it carefully evaluated the market to obtain the most appropriate CAM system to complement its investment in Pro-ENGINEER which was selected because of its all-round universality and the ability to accept files from a host of different systems used by customers.

Plate 1 Pathtrace's EdgeCAM is linked to Pro-ENGINEER to provide seamless design to manufacture at IPE of Southend-on-Sea

Brian Spading, engineering manager, explains: "our trawl of available programming software, including the CAM element of both Pro-ENGINEER and CATTIER revealed in our view, a lack of flexibility. For the way we need to work, we found they were restrictive and always made the user follow a certain path."

The decision to select Path trace's Edge CAM was, he says, based on the system's universality. "It allows us to machine component features using our methods, and because we had built up a legacy file of programs from some years' experience of Path trace's early PAM software, these could be used, too."

IPE was set up 40 years ago when founder Alan Johnson worked at Southland Airport, Essex, and noticed that pilots were taking time off due to back strain and leg problems caused by uncomfortable sitting positions when flying for long periods. He designed a seat with adjustable lumbar and leg support, and established IPE (Industrial Precision Equipment) to manufacture the seats for pilots, co-pilots, navigators and engineers. Another company, IPECO, was set up to carry out design.

Today, the group employs 512 people in four separate facilities at Southend-on-Sea. Producing around 200 seats per month, IPECO claims to be the world's largest manufacturer of aircrew seats, making virtually all the seats for Boeing as well as supplying other aerospace companies.

IPE, which employs 222 people, manufactures all the components for IPECO. It also provides a subcontract design-to- delivery manufacturing service to the civil and defence aerospace industry, and includes companies like BA Systems, Alenia Marconi Systems, GEC, Thales and Ultra Electronics on its customer list.

To provide such a high level of service from component and assembly design, through production to despatch, IPE has a wide range of manufacturing skills and as part of an ongoing investment programme, it has its own paint shop and pressure testing facilities as well as a raft of CNC machine tools.

Before deciding to upgrade to EdgeCAM, Brian Spalding visited a number of companies with both Pro-ENGINEER and the Pathtrace software, to determine whether the software was truly seamless when using specific translators. He saw no evidence of communication or interface problems and since integrating EdgeCAM with Pro-ENGINEER, IPE has found their operation to be totally seamless.

Apart from direct working on the Pro-ENGINEER solid model, one key advantage of EdgeCAM is Code Wizard post processor compiler, says IPE. The company has developed a method of sending post-processed programs to either of the shopfloor computers. Here, the post-processed programs can be assigned directly to the appropriate machine and the program immediately processed.

Brian Spalding explains: "each machine tool post processor takes into consideration the age of the machine and the type of tooling to be used, then automatically adjusts the speeds and feeds accordingly. This means all similar machines are compatible for example, a vertical machining centre with a pallet is compatible with any other vertical machine having a pallet. The fact that the control is different is irrelevant; as long as the operating principle of the machine is the same, we just click and post it away and it goes."

He reflects how they used to spend hours sorting out the differences between machines "This was because we always used to post-process the code and edit it. It would then go out on the shopfloor for prove-out on model resin and, if it looked good, we would take the risk and cut metal. Now all we do is post- process it, run it through verification and ship it to the machine. We very rarely use resin to check programs and this is saving us a great deal of time," he maintains.

He describes how Cutters are selected by manufacturer. "We use a range of tipped tools and all relevant insert speeds and feeds are built-in. This means any programmer can pick up the program and the same uniform set of data is automatically fed into the program. We do not even have to specify machining speeds or feeds – the post-processor takes the data and adjusts the figures according to the machine."

When a tool is selected, all cutter details are transcribed onto a sheet and the operator quickly selects the appropriate tool and holder.

Prior to having the level of control now afforded by EdgeCAM, operators could change speeds and feeds, and overwrite programs, which would then become the proven master. But now, according to Brian Spalding, if a program is sent back it goes into a particular directory. If there is no explanation why it is different, the original is retained as the master. However, if there is a reason for a change, the source program corrected and post-processed.

So well has the system worked that last year only six inspection reports were filed for scrapped work. "That is less than half a per cent, which is a massive improvement", says Brian Spalding. "Missing holes and chamfers are a thing of the past with EdgeCAM, because everything is verified. You can even measure on screen and you can virtually perform your own inspection on the model before it goes for machining." Electronic models are used extensively because much of the company's work involves initial component development. Since the CAD model represents a perfect part, there has to be a manufacturing allowance, adds Brian Spalding. "The engineers will say what holes they want to be accurate at prototype stage and, obviously, when things develop, we get a set of drawings with tolerances and finishes. EdgeCAM is excellent at breaking down every drawing format. It is universal in its acceptance, flexible in how you want to program it and very powerful at outputting NC code", he says.

Another important step towards the paperless environment has come from the EdgeCAM Job Manager, as Brian Spalding confirms: "a job used to go out in an envelope with a list of tools, settings, the program and remarks from previous operators. The envelopes would disappear into black holes and hours could be spent looking for things. That has all been eliminated as all the information is now contained within EdgeCAM Job Manager, and it is readily at hand – which is quicker and means we have fewer problems."

Brian Spalding describes how IPE is now developing macros to shorten programming times on its CNC sliding head lathes. "We can do this because most turning work involves various lengths of tubes, to hold together the seat side frames. The macro will intuitively ask for details such as diameter, bore sizes, chamfers, cross-drilled hole positions and orientation which are input by the engineer. The relevant speed and feed data is taken directly from the EdgeCAM Tool Technology Library."

He maintains: "this initiative has so far reduced the programming time using EdgeCAM from around 4h to just 15min. The macro generates a diagram of the part and, behind this, generates the NC code with a dedicated post-processor suited to the lathe."

IPE started free form surface machining last year, to meet the aesthetic demands of the latest seat designs. "The resulting programs are so large that they have to be drip fed to the machines and fortunately this is not a problem for EdgeCAM," he concludes.

Details available from: Pathtrace. Tel: +44 (0) 118 975 6084; Web site: www.edgecam.com