Cutting hardened steel, titanium and other difficult materials requires picking the right tools, eliminating spindle runout and relying on best practices to achieve tight part tolerances. Of course there is the ‘small’ matter of investing in the right equipment that can perform the metal processing tasks that you require while also giving your workpiece a more precise finish and not break down during machining.
Steel, cast iron and aluminium are the workhorse metals most industries rely on and are generally machinable on most machines. However, working in the aerospace, defence or medical industries often means working with difficult metals. These shops rely on hardened steel, titanium, heat-resistant nickel alloys and other materials that are notorious for the difficulties they present to machinists. Jpt Laser Marker
When working with exotic and difficult to machine metals, following correct practice is key. Machining hard metals is a delicate process. There is a lot of room for error, machining takes more time, and you have to fine-tune every aspect of your process. When you’re dealing with expensive, exotic materials, preparation is critical.
Donnees Engineering owner Johan Koen
When cutting difficult materials, one of the most important considerations is the cutting tool itself. Getting the tools to last is one of the biggest challenges. Harder metals can eat through the wrong inserts almost as quickly as you can replace them, and some materials warp and bend in ways that can keep heat trapped in the cutting tool.
Experts also emphasise how valuable it is to have the right coating. “Coating is very important, especially with harder materials. If you use a standard coating on a carbide end mill, you’re going to burn through that quick. If you use the proper coating, with the proper speeds and feeds from your supplier, you’re going to be able to fly through the material, you won’t burn up your cutters, and you will hold to tolerance.”
Machining shops will have a good idea of whether to use cutting tool fluid, which tool geometries work best for a given material and under what circumstances, and which coatings will work best for a given material.
One of the Mazak CNC machines, which was manufactured in 1987, is still producing components for Donnees Engineering today
Donnees Engineering now have eight Mazak machines on the floor. They include four vertical machining centers, three lathes and one Integrex j-200. All machines have been supplied by Hi-Tech Machine Tools. The Integrex j-200, our most recent purchase, is a compact machine designed for large workpieces – maximum machining size is 500mm and maximum machining length is 500mm. Additionally, a large machining area is provided thanks to long strokes: X-axis – 450mm, Y-axis – 200mm, Z-axis – 550mm, B-axis indexing range of 220° and C-axis of 360°. The orthogonal Y-axis machine construction allows face milling, end milling, and drilling to be performed in the large machining area without C-axis indexing thanks to long Y-axis stroke: 200mm
Machine tools designed for machining titanium are generally characterised as having heavy, rigid structures with spindles designed for high torque at low spindle speed. Large spindle tapers and high-pressure coolant are also typical. For multi-axis work, a beefy trunnion and rotary table may be provided as well.
However, users need to learn about the difficult to machine materials such as titanium, understand their characteristics and apply basic principles knowledgeably. And any serious effort to master the machining of these materials must follow this call earnestly.
“There is just something about machining parts on CNC machines – the ability to manufacture precision, good looking parts and making thousands of them – all within the tolerances given by our clients,” expounds Johan Koen of Donnees Engineering, a precision machining company based in Paarl in the Western Cape.
The Mazak Quickturn 200M lathe
Donnees Engineering are capable of machining components from small to large. 73 000 components were machined last year
Donnees Engineering is a relatively young company, having only officially opened its doors for business in March 2006 as an after-hours business. But sole owner Koen had been machining precision components for many years prior to starting his own business.
Koen worked for a global company that was also based in Paarl but it was not in the business of manufacturing components but rather one of supplying product to the retail industry and had been doing so since 1904.
“I joined a company that is now known as BAT South Africa but was previously known as Rembrandt as an apprentice. I qualified as a fitter and turner with them through Northlink College. Once I had completed my internship with them, I received my recognised and accredited qualification, which would have given me access to the world of work in South Africa.”
Components that have been machined
This aluminium gear box cover started off as a 40kg block and after final machining it weighs 5kg
“I stayed on with them because of the work that I was involved with at the company. Its main focus was of course the manufacture of cigarettes but the company had a stringent high-quality manufacturing policy and as a result the manufacturing equipment had to match these high standards set. We therefore were exposed to some high-quality, top-end CNC equipment in the company’s machine shop.”
“It was not the company’s policy to shop out the maintenance and servicing requirements of the manufacturing equipment and all the auxiliary and add-on services that were required in the manufacturing and packaging processes.”
“However, the company’s requirements could not keep the machine shop running at full capacity so work was acquired from other companies that required machining of components. This filled most of the spare capacity and kept myself and other colleagues busy with producing high-tech components. We had four Mazak CNCs on the floor so we were more than capable of producing the required components.”
When Donnees Engineering purchased the machine shop from BAT 16 years ago this lathe was part of the deal
“Having been trained on Mazak machines and then acquiring them for my business I certainly do have a love affair with them. When it comes to technology, the shop’s philosophy is to acquire the very best-built machines, in our opinion,” said Donnees Engineering owner Johan Koen
“One of the more interesting projects we were involved in was components for the second South African satellite known as SumbandilaSat (‘pathfinder’ in Venda), a satellite that was created by start-up company called Sun Space and Information Systems (SunSpace). The South African Department of Science and Technology to Stellenbosch University were also involved and the satellite was launched in September 2009.”
“However, 16 years ago Paarl was shocked when one of its economic giants, the company I worked for, decided to close the BAT factory in Lady Grey Street and consolidate all its manufacturing and operational activities to their Heidelberg plant in Gauteng.”
“As they say there is always a positive that emerges from a negative and this was certainly my case. I had seen what was happening at BAT and decided already in 2006 to register a company – Donnees Engineering – and also put together a business plan. As soon as it was official that the Paarl operation would close, I put my proposal in and it was accepted, thank goodness.”
One of the newer Mazak machines on the floor is the Quickturn Smart 200
“I acquired four Mazak machines, some conventional equipment and 12 staff. One of the Mazak CNC machines, which was manufactured in 1987, is still producing components for me today.”
“Fortunately, I was able to continue with all the outsourced work, including the Sunsat components, as well as acquiring work from BAT. The BAT work continues today and it includes refurbishment of existing machines and manufacturing of new machines to produce cigarettes.”
“Since then, we have grown year in and year out to where we are today, manufacturing components for various leading companies and working with many different industries. Combining efficiency and accuracy we keep moving forward, always keeping up with the latest technology and strategies from across the globe, to produce quality components and keep our clients happy.”
The company has some bar work to do and it relies on an Okuma Genos L200E-M
The company’s Fanuc Robocut EDM can cut hardened materials up to 310mm in height
“We do work for the canning factories and there are plenty around in this area of the country, the wine industry, filling industry and various aerospace companies, and many others.”
“Last year we machined 80 469 different components from one-off orders to multiples of the same.”
“Most of the machining is done from solid materials but where it is required, we will machine castings. This includes all types of material. We are not concentrated on difficult to machine materials but do regard ourselves as specialists in this area.”
Donnees Engineering also trains their own apprentices and currently they have four employed
“Many companies find niches supplying single industries, especially when those industries have an outsized local footprint. However, supplying components to one end market can turn a niche into a rut if that market experiences economic hardships. Many shops have learned to diversify their customer bases over the years, and this we have done.”
“But I have to admit that we are in a rut when it comes to the CNC machines that we purchase.”
Love affair with Mazak “Having been trained on Mazak machines and then acquiring them for my business I certainly do have a love affair with them. When it comes to technology, the shop’s philosophy is to acquire the very best-built machines, in our opinion. Additionally, choosing a single brand of machine tools enables our operators to be self-sufficient. They can quickly learn to set up and programme virtually any machine in the shop. More importantly they are not just operators. They are all qualified artisans that set up, programme and operate and in most cases more than one machine at a time. They are the heart of Donnees Engineering.”
The BAT work continues today and it includes refurbishment of existing machines
The company also has contracts to manufacture new machines to produce cigarettes
“We also train our own apprentices and currently we have four employed. They learn the hard way, as I did. From the beginning of just using a file, for example. They don’t move on unless they are experts at using that file.”
“We now have eight Mazak machines on the floor. They include four vertical machining centers, three lathes and one Integrex j-200.”
The Integrex j-200, our most recent purchase, is a compact machine designed for large workpieces – maximum machining size is 500mm and maximum machining length is 500mm. Additionally, a large machining area is provided thanks to long strokes: X-axis – 450mm, Y-axis – 200mm, Z-axis – 550mm, B-axis indexing range of 220° and C-axis of 360°. The orthogonal Y-axis machine construction allows face milling, end milling, and drilling to be performed in the large machining area without C-axis indexing thanks to long Y-axis stroke: 200mm.”
“However, it is not just our Mazak machines that provide accurate and efficient results “Done-in-One”. Our fifth Fanuc Robodrill CNC machine is a 5-axis machine and also completes machining operations “Done-in-One”.”
A general view of the immaculately clean and well laid out machine shop
Fanuc Robodrills “Mazak have coined the term “Done-in-One” with their Integrex machines. This is a term in 5-axis machining that means you cut a part from start to finish, all in one operation. This is an extremely accurate way of machining and a time and cost saving operation.”
“However, it is not just our Mazak machines that provide accurate and efficient results “Done-in-One”. Our fifth Fanuc Robodrill CNC machine is a 5-axis machine and also completes machining operations “Done-in-One”. Besides the five Fanuc Robodrills we also have a Fanuc Robocut EDM that uses wire to cut parts. This machine has so much to offer and it can even cut hardened materials up to 310mm in height.”
“At Donnees Engineering we use Mastercam to generate the most efficient code and toolpaths necessary to cut complex parts. Our seats involve lathe, mill 3D, multi-axis and wire. Every year we update our maintenance to always stay sharp and up to date with the latest technology. Mastercam is a very powerful tool in manufacturing, allowing us to reach the efficiency and accuracy needed to complete the job.”
“We use Solidworks in our design department.”
In the quality department the company has a Brown & Sharpe CMM, shadow graph and hardness testers as well as a Sisma laser marker.”
The company also offers a UV Printing as a service
Donnees Engineering also has a DMG MORI DMU 80T on the shop floor
UV Printing “Not through design or planning we now offer UV Printing as a service. A client needed some aluminium covers that we manufactured and machined for them – 100s of them – printed with their logo and some other text. We did some research, invested in a machine and staff and the result is we now offer this as an extra service. It is a thriving business that we have developed.”
“Our business is not just about making chips. We are running lights out to keep our clients happy. Dodging the load shedding with an investment in a generator has kept our 36 staff employed. We intend to keep ahead of the game.”
Laser Tubes For further details contact Donnees Engineering 082 789 3818 or email johan@donnees.co.za or visit https://www.facebook.com/donneesengineering/