The Okuma Double Column Machining Centre (DCMC) range of CNC Machines has earned the tag of ‘benchmark’. Without doubt, since 1966 Okuma DCMC’s have outclassed every rival by the long-time cultural ethic at Okuma and the phenomenal success in the field of the thousands of DCMC’s that bear the Okuma name.

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Since 1966, DCMCs have been achieving phenomenal success, with thousands of machines in operation today

In October 1981, the first Okuma DCMC for the Australian and New Zealand markets was completed and delivered to a customer in Christchurch, New Zealand.

Okuma DCMC’s are defined by their basic construction. Often referred to as bridge construction, Okuma prefers the DCMC description as Okuma DCMC’s have fixed columns either side of a Table that moves underneath the elevating cross rail (W Axis) connected to the two columns along which the Y axis/Main spindle headstock travels. It’s actually similar to the MB-V/Genos M Vertical Machining Centre (VMC) range Okuma also leads the market with.

The key for the DCMC is the 5 face machining ability using a choice of angular, extended or high speed attachments. For example, an NC B and C axis tilting, rotating head attachment along with 3 other chosen vertical or angular attachments can be stored, all of which are automatically exchanged (AAC) by program command. All can accept cutting tool holders that are also automatically exchanged (ATC) irrespective the attachment selected. It’s not uncommon to add an  4th Axis NC Rotary table arrangement and even 2 pallets!

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Okuma DCMC’s are defined by their basic construction, often referred to as bridge construction.

Okuma’s DCMCs are by design and quality, machines that stand the test of time in longevity and that remains critical when analytical investigations into specifications, prices and delivery seem to be an immediate, nevertheless important focus.

The fact is that the first MCV-A delivered to our New Zealand customer 37 years ago is still in active use.

There are four key factors that always surface when we discuss Okuma DCMC’s with our customers:-

  • Firstly, the expectation of high accuracies in such a big machine tool.
  • The second factor is reliability.
  • The third factor is usability. Okuma DCMC’s are big machines but operators need to be confident to tackle a machine that can go as big as 3.5metres between columns with a 12 metre long table (35 x 120).
  • Finally is on-going support by not just the local distributor but by the manufacturer.

The order of the above and their priority may vary from enquiry to enquiry but they are the most important and FAQ’s so let’s look at each of them.

ACCURACY:

Okuma has now been producing DCMC’s since 1966 when the MDB was released. In a classic case of “if it ain’t broke, don’t fix it” the Double Column concept has stood the test of time with real improvements coming from modernised casting techniques, more efficient machining of components, materials used and perhaps above all else the every improving electrical and electronic devices and software developments.

The slide ways of a DCMC cannot just be machined. They must be ground. Massive investment is made in Waldrich Coburg Slide way grinders that can and must be able to grind the full length of the individual large components such as all ways, columns and beds to within single digit microns for flatness and straightness. These are the parts that guide the moving table, cross rail and the headstock and upon which the whole aspect of squareness and overall accuracy depends. As for the Vertical axes, there are two. The elevating cross rail, W axis, that can be continuously NC controlled or pre-set with high accuracy at any one of 10 positions. Attached to the elevating rail is the Y axis saddle to which the second vertical movement axis, the Z axis is attached. It is of square ram-type construction and supported by proper slideways for superior rigidity.

Okuma’s unique combination slide/roller guideway system on all main axes allows spritely axis feeds without significant thermal change. Thermal stability of the whole machine itself is controlled these days by Okuma’s award winning Thermo Friendly Technology that, in simple terms, is a negative of the thermal map developed under machining conditions of every machine individually. This global award winning technology has revolutionised the control of part repeatability over long machining times and integrates ambient temperature changes as well. 

Every Okuma DCMC is built to order. There is no stock specification. Every Okuma DCMC is manufactured and assembled completely as per the Customer’s specification at the factory in the giant Kani 5 DCMC assembly hall where around 35 DCMCs are assembled simultaneously. It is then vigorously tested to ensure compliance with Okuma’s stringent accuracy standards, in most cases with the Customer present as a witness. The machine is then disassembled for packing and shipping. Typical accuracies for an average MCR BIII 30 x 65 DCMC are as follows:- (e.g. 3.0metres between columns x 6.5metre table length)

1) Parallelism:                               Better than 0.03mm - usually 0.02mm

2) Straightness:                            Better than 0.02mm/ metre – usually 0.10mm/metre

3) Squareness:                             Better than 0.03mm/500mm – usually 0.015mm/500mm

4) Bidirectional Repeatability:      X axis, Y axis, Z axis and W axis: All <0.010mm

Having said all that, accuracies can be a dynamic matter and are often best achieved in the set up and levelling process at installation time and they will vary from machine to machine. The point is Okuma consistently produces large machines with exemplary performance outcomes upon which their global benchmark status in DCMC manufacture is founded.     

RELIABILITY:

Okuma holds a prominent position in the market for reliability. This comes from a long standing internal culture of continuous improvement – since 1898. 120 years ago, a young Eichi Okuma explained to his staff that “Trust is important. To obtain trust, you must satisfy the customer”. This was not just about selling machine tools. It was about trust. Trust in your machine for reliability and accuracy, in the manufacturer, in the supplier, in the support chain including spares and service, in the management of the supplier and so it goes on... 

Where most trust in Okuma is created is from the simple fact that Okuma makes the lot – machine and control - and is the sole source for support. In addition to that, Okuma aims at lifetime support for parts which in the case of DCMC’s, are rarely needed. It’s a key reason for examples like the New Zealand MCV-A to earn a current place in their shop and where it’s been paid off financially time and time again over its 37 year life so far. This support based trust doesn’t come automatically. It’s evolutionary and its 120 years’ of experience that is crucial to how reliably and effectively any glitch is corrected. The DCMC build program by Okuma has been active for over 50 years and the documented experiences inside Okuma provides a massive platform for experienced troubleshooting.

USABILITY:

The same Okuma OSP controller, language and architecture that is used on our small tool room VMC, the MB-V, is used on the massive MCR-C 35 x 120 DCMC. All DCMC’s offer straight ISO or Okuma’s own conversational formats. So there is a consistency of operation criteria that will allow an operator to confidently switch between large and small Okuma machines.

These days, however there are several more application based options that are designed to provide more user driven outcomes. Machining Navi – that will seek the optimum machining conditions of speed and feed rate, Servo Navi AI – intuitive acceleration and deceleration variability against the mass of the part. All manner of Gauging options, Laser surface hardening and metal deposition, Machine condition analytical monitoring, Super NURBS, physical dimension compensations, Servo Vibration Auto Adjustment, Collision Avoidance System,  Power conscious ECO options for idling stop and monitoring not to mention Inductosyn scale feedback, NC-W and or NC Rotary table axes and the wide array of Attachment Heads.

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The key for the DCMCs is its five-face machining ability, using a choice of angular, extended and high-speed attachments

For an investment that is generally large, there needs to be a comprehensive set of features that assist the perfect outcome of what can often be a one-off job that just HAS to be right first time.

SUPPORT:

Of the 40 odd DCMC’s that have been installed in Australia over the years, some are old. The average age of all 40 machines in our market is 21 years. Every single one is operating today.

Owners can look forward to remarkable reliability but more importantly a sturdy and second to none support program that involves local Applications, mechanical service and electrical service employees who are well experienced on all the models because all Okuma DCMC’s follow a generally common design criteria. In addition to that, for every DCMC installation, Okuma factory engineers will attend to take charge of the complete assembly and commissioning process.       

Okuma Double Column Machining Centres are a major part of the Okuma machine range that includes vertical and horizontal spindle CNC Lathes, Vertical and horizontal spindle Machining Centres, Multifunction turning centres and 5 axes machining centres, cylindrical and internal grinding machines, robotic handling equipment and the full scope of the OSP Control including motors, drives, encoders and software.

If we rely on them, you can too!

Okuma is represented in Australia by Okuma Australia Pty Ltd and in New Zealand by Okuma New Zealand.

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