Case Studies

Standard practices, extraordinary results

Over the past few years West Yorkshire-based Kavia Tooling has standardised its manufacturing methodology and hardware. And, with the help of Planit’s powerful CAD/CAM software, Edgecam, the company is able to compete with mould tool makers from across the globe.

ISO 9001 accredited Kavia Moulded Products has been making injection moulded parts for over 30 years. Like many moulded parts specialists the company operated an internal toolroom to manufacture the moulds required, but three years ago it took the strategic decision to operate the toolroom as a standalone business entity and it has grown from strength to strength.

Managing director of Kavia Tooling, Chris Cole, has worked for the company for over 20 years. He says: “Around seven years ago we standardised on Meusburger mould tool assemblies and plates, and that’s when all the systems used today started to fall into place. To machine the mould cavity we use Hurco CNC vertical machining centres with conversational programming. However, as CAD technology has become more available the demand for 3D shapes has increased so we invested in Edgecam, because we were struggling to program the more complex injection mould tools at the machine.”

When Kavia Tooling selected Meusburger as its preferred supplier the company received all the backing and support required. “The same can be said of Edgecam,” Chris Cole states. “In fact, when we buy the next CAM seat we won’t be going with any of the other systems available because we have standardised on Edgecam. I have selected the best available and will stick with it. As far as I am concerned, if you don’t standardise you don’t stand a chance.”

With five highly skilled staff, Kavia Tooling supports customers in many different industry sectors, including white goods, electrical and electronics, textile and so on. A current project involves a suite of mould tools for animal husbandry. Although the balance of work alters, on average around half of the moulds produced are for the mould shop. Turnaround for mould tools is typically four to six weeks depending upon the complexity, but this time includes product trials of the tool and finished component pass-off.

Chris Cole says: “10 years ago we would get involved with the design of the part, design and manufacture the mould tool, and then produce the parts required, but in the past five years many companies have invested in CAD systems and can actually do the design in-house. Today, we carry out about 30 per cent design of customer components, the rest arrive as Step or Inventor files, as well as IGES files and we work from this data.”

Kavia Tooling uses Autodesk Inventor Tooling, a software package designed specifically for the mould tool sector. Chris Cole did a lot of development work with Autodesk for its Inventor Tooling package before it was launched, working on the Beta version to ensure it covered all the areas a mould maker needed efficiently and logically. For example, Tooling can apply the component shrinkage automatically depending upon the material being used.

Explaining further how Kavia Tooling’s standardisation works, Chris Cole says: “Every time we open a drawing file it is configured to look the same. We operate a paperless environment and read only files are shown on the shopfloor. Each part of the mould tool assembly is stamped with the project number and this number is used to reference any software files, such as the Edgecam cutting toolpath file. We have made the system as simple as possible to eliminate the chance of any mistakes.

“We use a pastel blue colour on the components when the shrinkage allowance had been applied. And this file is taken into the assembly drawing of the tool. We don’t produce inserts, but machine the whole tool cavity into the tool bolster in one go, even if it’s hardened tool steel. We avoid spark eroding where possible, although sometimes we have no choice if there is a specific surface finish required.”

Tool parts are selected from the catalogue and transferred to Inventor as a solid model and the order is emailed to Meusburger at the same time. This order keeps the same number as the rest of the project, so it is fully traceable.

“Everything we do is computerised from mould flow analysis to CAD/CAM and on to the shopfloor. The Inventor file is selected from the network and Edgecam applies the cutting tool paths to the cavity or the electrode, or sometimes both. Any modifications to the solid model design in Inventor are automatically updated in Edgecam because it is using the same solid model. Edgecam will notify you that the model has changes and ask if you wish to modify the program. It keeps control over the design and we know exactly where we stand,” Chris Cole confirms.

The same cutting tools and techniques are used - whisker cutting with just a light loading at high speeds - on the machining centres. Kavia Tooling has eliminated downtime by applying the cutting tools in the best way, established by empirical testing. Generally the company uses just one 10 mm diameter tool to machine a mould tool to a plus 0.5 mm material on condition.

Says Chris Cole: “Within Edgecam we use associative datums, such that the level and clearance of every part is associative. For electrodes, which are often machined four at a time, this is important. It takes a little longer to write the program and get it spot on but if you plan on running a machine for three days non-stop you have to spend a little more time getting everything correct. However, once it is running you can get on with other jobs.”

The electrodes are densely packed on to the machine’s worktable but Edgecam provides program simulation before any material is cut to ensure there is no collision. “Without the simulation I would not be able to do what I am doing with the same level of confidence. When you set the machine going on a Friday and it is still running Monday morning you want to be sure it’s right or there is a lot of money wasted in terms of material and downtime. Without these manufacturing systems and Edgecam software there is no way we could have up to 12 complete tools in production at a time,” he points out.

In fact the company has a checking procedure which is carried out before the cutting cycle starts. The check list includes datum points and tool checks, and it works because Kavia Tooling rarely suffer a crash. Chris Cole says: “An extra 10 minutes to check something is insignificant compared to the week or so it will take to get back to where you were if it’s wrong. It only has to be 50 micron out in some cases to be scrapped.

“There is nothing fancy about how we do things: the simpler you can make it, the easier it becomes for everybody. As I often state to our apprentices, if anything seems complicated you’re doing it wrong.”

The way Kavia Tooling operates allows the company to compete with the Far East and it has seen plenty of work has coming back as a consequence of the cost of transport and the increased rates of the tool makers in China. Chris Coles quotes a two-part key pad moulding for a blue chip company as an example. For this work the company was up against mould tool makers in Singapore, Taiwan and China and Kavia Tooling won the job.

Having recently moved into a larger 6000 ft2 workshop the company now has space to grow to meet market demands. However, the standard practices will remain, as Chris Cole concludes: “All of the elements are in place and they all complement each other, the machines, cutting tools and the fixturing as well as Edgecam software. It works so smoothly, and we are so efficient, that we can reduce the cost but retain the quality. It allows us to take up to a third off the price of what companies pay elsewhere in the UK.”