March cover story: Swiss precision 

For any tooling manufacturer, developing products that perform well on difficult to machine materials like titanium, stainless steel and heat resistant super alloys is challenging enough. But then add ultra-small diameters and depths up to 50 x D into the mix and things get really interesting. Fortunately, it’s all in a day’s work for Mikron Tool and its range of Crazy tools as Dave Tudor learned when he visited its Agno, Switzerland headquarters.

Emerging from Mikron Machine’s Cutting Tool department in 1998, Mikron Tool is part of the Mikron Group which also includes Mikron Transfer Systems and Mikron Automation. Manufacturing highly precise rotary solid carbide cutting tools – drills, mills, reamers, and chamfering and deburring tools – in diameters from 0.1mm to 32mm is its sphere of expertise.

This is a company steeped in engineering heritage built upon nurturing longstanding close relationships with its customers to develop customised, proven solutions. It’s not surprising therefore that around 50% of Mikron’s products are for customer-specific applications. Testament to this lifetime support ethic is the fact that every single sales person employed by the company has a technical background.

20 years ago at the time of its formation, Mikron Tool’s headcount comprised just 30 members of staff. Today the company employs 245 people across four sites in Agno, Switzerland (the headquarters), Rottweil, Germany (the main stocking and warehouse facility), Monroe in the US and Shanghai, China. Through a network of highly trained technical sales partners, agents and resellers, the business has a strong presence in 48 companies globally. Closer to home in the UK, the sales office is headed up by Lee Wilkinson.

Whole new ball game

“Initially, Mikron Tool was set-up to support the endeavours of the Transfer Machining Division which at the time was heavily involved with the manufacture of ballpoint pen tips for companies like Bic,” says Marco Cirfeta, head of sales, Europe at Mikron Tool.

“Today we are clear how ballpoint pens should write; but in those days the process was much less defined. Ballpen tip tolerances need to be held within microns to ensure an even flow of ink so the tooling needs to be ultra-precise.

“Our challenge then was to develop a fast, stable, precise and highly repeatable process and that’s exactly what we did,” he adds. “Today, 145 million ballpen tips are produced every day and 95% of all global production worldwide is on Mikron transfer machines with many using our tooling. Up to 300 tips a minute are produced on a single machine– and Bic is still a customer.”

A word or two about rotary transfer machines at this point is probably pertinent. The largest machines Mikron produces are effectively 24 CNC machining centres within one machine. Tool changes can take one and a half to three hours so long tool life is absolutely vital to maintain acceptable levels of productivity.

Crazy about tooling

Mikron Tool’s ‘CrazyTool’ range has actually been around since 1999 but a decision was made in 2014 – driven by customer demand – to establish a focus on difficult to machine materials such as stainless steel, cobalt chrome alloys, titanium and heat resistant super alloys (HRSAs) – for example Hastelloy or Inconel. According to Marco Cirfeta, around 20% of the company’s overall business today is concerned with processing challenging materials.

“I believe that this percentage will grow year on year,” he predicts. “At the moment we’re relatively new in the special materials field and so there are many companies that simply don’t know what we do. We see great potential in sectors such as oil and gas, aerospace and medical as well as established markets such as watchmaking, automotive and dental. In the UK, aerospace will be a prime focus for us.”

The Mikron Technology Centre at Agno

Recent projects in the medical sector have seen Mikron Tool partner with DMG Mori and Schunk. One such example was with the development of a distal radius plate manufactured from titanium for a customer needing to significantly reduce the cost per part.

“DMG Mori were close to securing a sale of one of their Milltap 700 machines with this customer but he was hesitating because the cost per part was too expensive using their previous tooling supplier,” Mr Cirfeta recalls.

“DMG Mori approached us to see if we could help so we worked together on the project for three months. Our solution comprised 12 Crazy tools, ranging from 0.5mm diameter up to 8mm, across 25 operations on the DMG Mori machine using Schunk Tandem KSP Plus 100 workholding.”

The results speak for themselves. With the former tooling supplier, cycle time per part was two hours eight minutes; the DMG Mori/Mikron/Schunk solution reduced this to an astonishing 42 minutes.

“Much of the cycle time reduction was achieved by removing many of the high speed toolpaths our competitors were using,” says UK area sales manager Lee Wilkinson. “Our tools are so effective at slotting, we were able to remove metal much more rapidly by ‘chunking’ the material rather than having to take more frequent but smaller cuts.”

On the Mikron tooling, through shank coolant was used throughout for targeted cooling – bringing the fluid into direct contact with the cutting edges to prevent overheating and chipping – and also providing efficient chip evacuation.

Small talk

Whilst Mikron Tool’s product range spans 0.1mm to 32mm diameter for customised tools, its Crazy range has focused on much smaller tool sizes from 0.1mm to 8mm. Mikron carries out all manufacturing in house with the exception of coatings which it subcontracts out to a trusted supplier and all tools produced in the past eight years are patented. Its manufacturing facility is impressively clean, modern, and high-tech. This is Swiss precision at its best.

Focusing on smaller diameters in the Crazy range has enabled Mikron Tool to develop some pretty impressive diameter to depth ratios. For example its range of Crazy drills start at 0.1mm diameter and can drill to depths of 50 x D. On the milling front, diameters range from 0.3mm to 8mm and can plunge to depths of 5 x D.

Lee Wilkinson, Mikron Tool’s UK sales manager (left) and Marco Cirfeta, head of marketing and sales, Europe

Specific products worthy of mention include the CrazyDrill SST Inox, a small drill for bore diameters from 0.3 to 2mm and for drilling depths up to 12 x D. Specially adapted for the difficult characteristics associated with machining stainless steel, it features a digressive flute configuration to facilitate a good chip break and swift chip evacuation.

According to Mikron, when compared to traditional drills, the CrazyDrill SST Inox offers double the feeds and speeds with drilling steps up to 1 x D.

The CrazyDrill Flex SST-Inox is a micro deep hole drill available in a diameter range from 0.3 to 1.2mm and capable of drilling to depths up to a jaw dropping 50 x D in stainless and acid and heat resistant materials. The special geometry with digressive flutes as well as the integral coolant channels are key to this tool’s effectiveness.

Featuring shank-integrated cooling, the CrazyDrill Pilot SST-Inox is an ideal complement to these carbide drills. Highlights include digressive flutes and effective chip removal characteristics and the fact that the tools are ground to such precision that there is no step between the pilot hole and the long bore.

For plunge milling, the CrazyMill Cool P&S is available in 1 to 6mm diameters and when milling depths of 2.5 x D enters up to 1 x D perpendicular into the material (drilling) and then progresses laterally to machine grooves and pockets in solid material.

It collects chips in its expanded chip collection section in the tool’s head while drilling and then evacuates them through the large flutes. Stable and robust cutting edges into the centre of the tool prevent vibration and integrated coolant ducts provide highly efficient cooling of the cutting edges.

(X Head) Training, trials and projects

A new Technology Centre, opened in 2015 adds a further dimension to the company’s service portfolio enabling the capability to test tools, produce prototype pieces and prove processes on behalf of its customers. Seven dedicated members of staff work in the centre.

“We’re seeing more and more demand for customer trials, training and project work,” explains Mikron Tools’ head of R&D, Alberto Gotti, “so the Tech Centre has become a vital part of our operations. So far, we’ve invested around 3.5 million CHF in equipment and technology which includes multi-axis machine tools and turning centres, coordinate measurement machines, a 100,000x electron microscope with EDX microanalysis, CAD/CAM workstations, measuring arms and contact/contactless surface roughness analysis equipment.

The manufacturing facility at Mikron Tool’s headquarters in Agno, Switzerland

“The aim is to replicate our customers’ manufacturing facilities as closely as possible, even down to aspects like cutting fluids so we can prove out new tooling and processes with 100% confidence that they’ll work,” he affirms. ”Each machine has a camera and screen installed so we can capture results on film and send to the client. Currently we undertake around 150 - 200 customer tests per year in this facility.

“We also use the Tech Centre for our own R&D – 50% of our resources in terms of people, machines and time is dedicated to developing our own new generations of products,” he explains. “This includes developing new coatings and carbide grades with our partners and new cutting geometries.”

Home truths

In terms of the UK market, Lee Wilkinson’s short and medium term plans are clear: “My objective is to further develop close working partnerships with a network of selected technical partners. We have already started some interesting collaborations in different regions and continue to look for more.

“In the longer term, the goal is to cover all of the UK with regional partners while working directly with key accounts.”

Mikron Tool www.mikrontool.com

 

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