Vertical machining centres make hydroforming tools

A Swedish hydroforming company has invested in an advanced CNC machining centre to make as much of its tooling 'in-house' and provide customers with a fast service.

An innovative Swedish has developed its own patentd production processes to develop the hydroforming process.

Hydroforming Design Light (HDL), based in Vansbro, Sweden, manufactures and assembles its own, high value hydroforming machines.

the various processes used in hydroforming require accurate dies.

Until recently HDL subcontracted out tooling to local subcontract machine shops, but has been investing in its own, in-house, machining facilities.

HDL's managing director, Alvar Palmcrantz, said: "We bought the Haas VF5 CNC vertical spindle machining centre from the local Haas Factory Outlet, a division of Edstroms, primarily to manufacture our tools and dies.

In the long run, when we have more Haas machines, we will have enough capacity to undertake at least 50-60% of our tooling requirements in-house.

A plant growing as quickly as this needs the capability to produce its own tools".

Palmcrantz continued: "We also bought the Haas machine because we want to be very quick to service our customers.

One of the impressive factors about the Haas is that we can machine steel dies as quickly as aluminium dies, which we make occasionally for lower volume orders.

That said, many of the cavities we machine are extremely complex and it is not unusual for some dies to stay on the Haas for a full day or even two".

The Haas machine has a TR 210 trunnion table.

Parts for the Haas arrive from HDL's ZCorporation Spectrum Z510 machine, which generates rapid 3D prints of high definition, full-colour prototypes from CAD models.

Palmcrantz commented: "We make 95% of our mistakes at the modelling stage, which means we scrap less material and save a lot of time".

* About hydroforming - the hydroforming prorcess is cost effective process for shaping malleable metals into lightweight, structurally stiff workpieces.

It uses water at high pressure to press room-temperature working material into a die.

The process forms complex shapes, shapes that would be difficult or impossible to produce using conventional solid die stamping.

Hydroformed parts can also be made with a higher stiffness-to-weight ratio and at a lower unit cost than traditional stamped or stamped and welded parts, said HDL.

* Hydroforming history - the hydroforming process has been around a long time, and today is one of the fastest growing metalforming technologies.

Historically, hydroforming was used to produce various items such as helmets for the British Army in World War I and kitchen tap spouts in the 1950s.

However HDL has developed patented machine construction and patented tooling systems to update the process and make it more cost-effective.

Palmcrantz explained: "In the past hydroforming has been more or less exclusive to industries manufacturing very large volumes (automotive, for example) or sectors with high investment capital availability (such as aerospace).

This will now change.

Our patented machine construction has, with all factors equal, an investment cost that is a fraction of what can be found available on the market today".

Palmcrantz said: "At the moment we are definitely a subcontract company, however, we already have customers who want to buy our machines, so maybe in a couple of years we could explore this potential revenue stream fully, but not yet".

* Draw deeper metal sections - hydroforming stretches material more evenly than conventional forming techniques such as stamping and deep drawing, and results in a more cost effective construction with lower weight - sometimes as much as 50% lower, said HDL.

In comparison with traditional methods, other hydroforming benefits include the following.

* An ability to draw deeper sections, tooling at less than half the cost of other techniques.

* Less material spring back.

* Higher precision on detail.

* Better surface quality.

Hydroforming Design Light offers three principle variations of the hydroforming process.

1 - Tube hydroforming starts with a tube placed in a tool that is then filled with fluid at pressures around 4000 bar until the pipe deforms into the recesses of the tool.

Automotive structures, exhaust parts, handles and furniture components are suited to this method.

2 - Sheet hydroforming is where sheet material sits on top of a tool and is deflected into the tool profile using high-pressure hydraulic fluid.

Many vehicle panels are produced this way.

3 - The 'pillow' hydroforming process 'inflates' two metal sheets joined by laser welding into the tool.

Containers such as fuel and oil tanks are manufactured in this manner.

Today, Hydroforming Design Light's main customer is Volvo Truck.

And while it's fair to say that automotive and commercial vehicles are the mainstay of the business, the potential for this innovative process is vast, said Haas to manufacturingtalk.com.

HDL is currently working on a diverse range of customer projects that include ski-poles, heat exchanger/water cooler parts, telecommunications components, refrigerator doors and aircraft seat frames.

All will benefit from tremendous weight and material savings without any sacrifice to strength.

"In another application we manufactured hexagonal framework tubes for radio masts," said Palmcrantz.

"The design increased component stiffness by 40%.

We calculated that for a 30m high mast, our version would weigh 89kg compared with 1400kg using traditionally manufactured parts.

With this method the customer could use stainless steel, which although is four to five times more expensive than galvanised steel for instance, would still be far cheaper overall".

Palmcrantz concluded: "Material thickness has nothing to do with component stiffness, shape is far more influential.

There are really very few limitations to hydroforming, perhaps just the imagination of the component designer".

* About HDL - Although a relatively young company, its turnover already stands at more than EUR 1.5 million.

However, at the end of 2008, HDL says this will be as much as four times higher.

The company is a member of the Hydroscand family of companies supplying industrial components to European customers since 1969.

Group turnover is approximately EUR 100 million, and the group's growth rate has exceeded 20% every year over the past five years.

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