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Tag: Doosan


The easiest way to avoid missed delivery dates and costly CNC machine repairs is to perform Preventive Maintenance (PM) on a regular basis. “Up to 40% of the repair work that I see could have been prevented by PM,” said Darryl Hardt, Assistant Manager of Service Training for Doosan Machine Tools America. “But tight production schedules can make it difficult to find time to follow the PM service schedules as outlined in the manual.”

This is why Doosan has developed a system that provides many of the benefits of Preventive Maintenance while fitting into the reality of operations in the real world. We call it the 6 F Program for Fluids, Filters, Fans, Function, Foundation and Fatigue.

The 6 F Program

“The 6 F program is mostly based on daily observation, common sense and reacting to small situations before they become major incidents where you have to tear the machine down to fix it,” Darryl said. There are 6 F programs for horizontal turning centers and vertical machining centers, but we’ll outline the general principles here.


Fluid levels, fluid cleanliness and fluid age play a dynamic role in the reliability of the machine’s operation. Fluids include, but are not limited to: hydraulic oil, lube oil, gear oil, chiller oil, air oil, grease and similar items.

Darryl’s tip: “If something smells burnt or musty when you walk up to the machine, some of the fluids may need changing.”


Filters not only need to be cleaned, they need to be unobstructed and intact. A torn or damaged filter will allow pollutants into the air or oil, and blocked filters will limit flow, resulting in malfunction.

Darryl’s tip: “Filters that are clogged with dirt can suffocate the component. Also use the right filter. Improvised filters may have holes that are too large, allowing contaminants to enter the inner working.”


Fans not only need to be operating, they need to be cleaned. They also need to be unobstructed and intact. A malfunctioning, blocked or dirty fan will limit airflow to areas that require it for cooling.

Darryl’s tip: “Keeping components at the proper temperature enhances their efficiency and reduces wear. A broken $20 fan can contribute to the premature failure of a costly servo motor.”


Most items are on a machine because they are needed. Never remove items, especially those related to safety.

Darryl’s tip: “There are buttons all over the machine that provide functions that help operate the machine. If you press a button and it doesn’t work, it should be checked. If it mis-operates once, it’s an abnormality…twice, it’s a curiosity…three times, it’s a problem.”


All machines will “settle” in their foundation. Over time, levelness of the machine can change. Crashing and vibration can cause a machine to “walk” if not lagged to the floor.

Darryl’s tip: “The entire geometry of the cutting area is based on the machine being level, square and parallel. Small variations in the foundation manifest as large deviations in cutting accuracy. Consider checking and re-leveling your machine after a few weeks and again every time you perform PM.”


A worn-out machine does not run well. Small issues, like a worn or damaged wiper on a way cover, can lead to large expensive ball screw and LM guide repairs if left unaddressed. Timing belts and drive belts that are worn, but “left alone until dead,” turn a simple repair into a time-consuming and costly one.

Darryl’s tip: “When an O-ring deteriorates, you may notice a leak of hydraulic fluid. Replacing those O-rings is a no-brainer. But when you take it a step further and think about the piston seals inside the machine, you may notice that replacing them brings the cylinder back to catalog spec pressure, helping functionality.”

Unloved, but Essential

Few machinists enjoy Preventive Maintenance, but ignoring it can result in your machine (aka your money maker) quite literally falling apart. Taking shortcuts on repairs and paying attention only to things on the surface and not thinking about what’s going on in the inside of a component leads to failure and a domino effect on other functions of a machine.

“Does using the 6 F Program take the place of following the Preventive Maintenance schedules as outlined in the manual that came with your machine? Of course not,” Darryl said. “But it will provide you with a fighting chance to keep your machine in operation and a daily PM awareness that may even cause you to pull out that manual and look at it once in a while.”

Doosan freshens wheeled loader for Stage V

Doosan has given its new DL420-7 Stage V wheeled loader not just a new engine but a new cab too.

As expected, with Stage V enhancements come reduced emissions and claims of better productivity.

The DL420-7 has a higher standard bucket capacity of 4.5 m3, the largest in its class, Doosan says, and provides a 7% increase in productivity over the previous ‘-5’ model. Automatic 5-speed powershift transmission and heavy duty HDL axles come as standard.

It is powered by the new Scania DC13 Stage V 6-cylinder engine producing 257 kW (345 HP) of power at 1800 rpm and providing a maximum torque of 2196 Nm at 1100 rpm. The new engine meets Stage V emission regulations without the need for exhaust gas recirculation (EGR), through the use of selective catalyst reduction, diesel oxidation catalyst and diesel particulate filter (DPF) after-treatment technologies. The ash cleaning cycle on the DPF has been improved to more than 6,000 hours and there is a DPF soot level indicator on the new 8-inch touch-screen display in the cab.

With no EGR needed and a new selection of power modes available – SAT2, Standard or Power – the Stage V engine gives a 5% reduction in fuel consumption, the manufacturer says. The new generation Situation Awareness Technology (SAT2) power management system automatically scans the machine’s activity and adjusts engine output according to real time analysis of the boom pressure, pump pressure and output shaft.

Doosan’s new Smart Key system on the control panel in the cab means that the operator can start the machine with a keyless device, helping to combat machine theft. Up to six machines can be registered on each keyless device and the Smart Key system provides remote door control, door lock and unlock, door release, searching and other functions. The control panel also includes two USB sockets.

The new EMCV (Electric Main Control Valve) joystick integrated in the armrest is another standard feature in the cab. The sensitivity of the joystick control can be set and altered according to operator preferences using the new touch-screen monitor.

The new cab has a Grammer Actimo XXL seat with adjustable horizontal and vertical suspension settings, a pneumatic lumbar function and seat heating as standard. There is a 3-point safety belt with alarm icons on the touch screen monitor and on the gauge panel.

Blind spots around the cab have been reduced with 14% more glass window area than on the previous DL420-5 model.

There is the option of electrically adjustable rear view mirrors for added safety. Full LED working lights are installed on the cab (four on both the front and rear as standard, with the option of six at the front and rear). The LED lights on the rear bonnet have an automatic strobe function to indicate when the wheel loader is reversing.

An air compressor with air blower is also available as an option in the cab, for cleaning purposes.

The DL420-7 is also factory-installed with the latest Doosan CONNECT TMS2.0 wireless fleet monitoring system.

Brief specifications for Doosan DL420-7 wheeled loader
Capacity, heaped:4.5 m3
Static tipping load, straight:18696 kg
Static tipping load, at 40°16493 kg
Length with bucket:8926 mm
Width with bucket:3200 mm
Height:3660 mm
Bucket hinge height:4265 mm
Dump height (at 45°) with bolt-on cutting edge2990 mm
Dump reach (at 45°) with bolt-on cutting edge1320 mm
Wheel base:3525 mm
Turning radius, bucket edge:7010 mm
Maximum travel speed (5th gear):40 kph
Engine:6-cylinder Scania DC13 Stage V, delivering 257 kW at 1800 RPM
Operating weight:23990 kg
Breakout force:171 kN
Tyre size:26.5 R25

Doosan’s new demolition excavators

The DX235DM is the first of three new high reach demolition excavators being launched by Doosan this year.

The larger DX380DM and DX530DM will follow later in the year.

Typical of the design of the new demolition machines, the DX235DM has a high visibility cab, tiltable to 30 degrees.

All three models have a modular boom design and hydraulic lock mechanism. This enables customers to use them for jobs other than demolition, changing from demolition boom to earthmoving boom. A stand is provided to facilitate the boom changing operation, which is based on quick-change hydraulic and mechanical coupler connections. A cylinder-based system is used push the locking pins into place to help complete the procedure.

The DX235DM equipped with the 18-metre long demolition boom can work with a demolition attachment to a maximum height of 16 metres. The recommended maximum combined weight for the attachment and quick coupler in this mode is 2.1 tonnes.

When fitted with the digging boom in the straight configuration, the DX235DM can work to a maximum height of 9 metres. In this format, the recommended maximum weight for the attachment and quick coupler is 3.3 tonnes.

Using the digging boom in the alternative bent configuration, the DX235DM can work with an attachment to a maximum height of 8 metres. In this mode, the recommended maximum weight for the attachment and quick coupler is again 3.3 tonnes.

The DX235DM has a hydraulically adjustable undercarriage, which extends to a maximum width of 3.74 metres to provide stability when working on demolition sites. For transport, the width of the undercarriage can be retracted hydraulically to 2.54 metres.

The mechanism is based on a permanently lubricated, internal cylinder design which minimises resistance during the movement and helps to prevent damage to the components, Doosan says.

Brief specifications for the Doosan DX235DM demolition excavator

  • Operating weight: 28.7 tonne
  • Maximum tool weight: 2.1 tonne
  • Maximum pin height: 18 m
  • Maximum pin reach: 12.9 m
  • Overall width (extended): 2740 mm
  • Overall width (retracted): 2540 mm
  • Overall height in travel position: 3070 mm
  • Overall length in travel position: 11460 mm
  • Tail swing radius: 2755 mm
  • Maximum digging reach (Digging boom): 9465 mm
  • Maximum digging depth (Digging boom): 6080 mm
  • Maximum digging height (Digging boom): 9450 mm
  • Digging force over bucket (ISO): 16.5 tonne
  • Digging force over arm (ISO): 12.6 tonne
  • Travel speed: low range 3.0 km/h, high range 5.5 km/h
  • Engine (SAE J1995 net): 124kW @ 1800rpm

Doosan aspires to tech leadership

Doosan has supplied us with an overview of new technology that we can soon expect to see on its construction, quarry and mining equipment in the coming months and years.

Doosan aspires to tech leadership

Under the theme of ‘Powered by Innovation’, Doosan Infracore Europe has announced a number of new developments to the its Smart Solutions portfolio. They include a strategic partnership with Palantir Technologies, an American tech start-up. This is the first of its type in Korea and forms part of the company’s efforts to provide new products and services by converging ICT technologies such as big data and the Internet of Things (IOT).

The service programmes within Doosan Smart Solutions also aim to maximise operating efficiency by creating a smart work environment. As part of this, Doosan has developed a mobile app for Apple and Android devices for its DoosanCONNECT fleet and asset management system, which now covers more than 70,000 Doosan machines worldwide.

To meet demand for machine guidance systems on excavators, Doosan Smart solutions is now offering Leica, Trimble and Xsite Ready Kits for wheeled and crawler excavators from 14 to 30 tonnes. The new pre-installed Leica, Trimble and Xsite Ready Kits can now be ordered direct from the factory through Doosan Smart Solutions for use with Leica, Trimble and Xsite 2D and 3D machine guidance systems. Doosan also offers factory-installed SVAB/Steelwrist tiltrotator options for the company’s DX140W-5, DX160W-5, DX165W-5 and DX170W-5 wheeled excavators.

Looking to the future, visitors to Bauma 2019 may have seen Doosan’s demonstration of long-distance remote control of machines with 5G (see below), or learnt about its ConceptX suite of solutions for site automation including fuel cell drones and autonomous vehicles. Doosan is looking to demonstrate ConceptX at an event in South Korea in November.

Charlie Park, CEO of Doosan Infracore Europe, says: “The construction, quarrying and mining industries are becoming increasingly digitalised. We want to stay ahead by investing heavily in new technology for our product development, which includes investing in our drone solutions and automated machine control. We are also partnered with many big solution providers such as Trimble, Leica, Moba (Novatron) and now Palantir.

“We want to be known as the most technology-friendly brand in our markets.”

Doosan Quarry Days

The Belice Quarry near Prague in the Czech Republic was the venue for the 2019 Doosan Quarry Days event that took place from 17th to 19th September 2019.

Customers from around Europe were given the opportunity to get hands on with 30 different Doosan machines.

It was the first opportunity to try out Doosan’s new Stage V ‘dash 7’ series medium crawler excavators, such as the 30-tonne DX300LC-7, as well as the DA30-7 articulated dump truck (a 30-tonne ADT), the DX250WMH-5 material handler (25 tonnes) and the DX27z, DX35z, DX63-3 and DX85R-3 Stage V mini-excavators.

Doosan Smart Solutions was also heavily promoted. To meet growing demand for machine guidance systems, Doosan Smart solutions is now offering Leica, Trimble and Xsite Ready Kits for the wheeled and crawler excavators from 14 to 30 tonnes. Doosan Smart Solutions also provides factory-installed options for the increased flexibility offered by Engcon and SVAB/Steelwrist tiltrotator systems for the Doosan excavator range.

DX250WMH-5 material handler

Above: DX250WMH-5 material handler

DA30-7 articulated dump truck

Above: DA30-7 articulated dump truck