East Asia Built, European Style

For many, Bauma will provide the first look around Doosan’s New Generation Dash-7 mini-excavator range.

In this post I'm featuring a recent article I did on the new DX27z for Earthmovers Magazine unedited and with video footage.

The first four of an 11 model range which will be rolled out over the next 3 years, four of which will be electric powered, and three are zero tail swing machines, the 2.8-tonne DX27Z-7, 3.9-tonne DX35Z-7, 5-tonne DX50Z-7 and the reduced radius 5.5-tonne DX55R-7.

These machines, which feature an all-new look and styling, are 100% designed and built in South Korea by Hyundai Doosan Infracore, effectively ending the tie up with Doosan Bobcat in due course.

Earlier this year, I was offered an exclusive visit to a pre-production model of the DX27Z-7 which was out for evaluation with customers in West Wales through long established family business and Doosan dealer, Mason Brothers.

The previous DX27Z was launched in 2019 and was effectively a rebadged Bobcat E27z, so I was keen to see what this all-new Doosan built model had to offer.

We travelled to a residential site location in Pembrokeshire where the machine was being put through its paces by a well-known local owner/operator Anthony Reynolds, who is currently running a DX27Z-5 model and a DX140LCR-5. Anthony has had 4-5 DX27Z’s from Mason Bros and has been a Doosan customer for over 20 years.

For many years now the chat on sites has long been that the Doosan was a just a Bobcat in a different colour and vice versa, nothing wrong with that of course, both are equally good machines in their own right, but with Hyundai’s acquisition of Doosan Infracore last year that will no longer be the case, hence this brand-new range of dedicated Doosan machines.

This was the first example of this new range that I had seen in the metal, and my first impressions were of a stylish, compact and very capable looking mini excavator, not wanting to drawer any comparison with the previous range, I could not help but see some similarities in styling especially at the offside rear panel.

The machine is brimming with leading top quality blue-chip components, with the main hydraulic pump and swing motor coming from Nachi, travel motors from KYB, the MCV (Main Control Valve) from Nabtesco, and the joystick controls are provided by Eaton.

Opening up the rear door reveals the in-house built, Stage V emissions compliant, 3-cylinder Doosan DN17 common rail diesel engine which produces a power output rating of 18.4kw (24.7hp) @2400rpm. As is often the case with these zero-tail swing machine’s everything is tightly packed in, but having said that, access to all the main fluid filters, air filter and coolant expansion bottle is superb, so there is no need to be a contortionist to perform regular servicing and daily maintenance.

Eagle eyed readers will notice the two pipes routed up to the optional air conditioning unit that was fitted to the rear of the cabin on this example, a most welcome addition on a hot and sunny day in Wales.

The fold out offside rear panel allows access to the cooling packs, the 38-litre hydraulic oil tank and battery isolator switch. The 12v battery itself looks to be located right down in the bellows of the upper-structure, which could make removal a bit tricky, but I have no doubt there will be a procedure in place to do that if and when required.

At the nearside rear, we find the filler cap for the 43-litre diesel tank, it is located within a recessed panel which should allow for ease of filling from a standard 25 litre container if required when working in remote locations.

Doosan states that the machine, which has an operating weight of 2798kgs, has been built on a new robust and durable undercarriage design. Sitting on the standard 300mm wide rubber tracks with a track length of 1960mm and width of 1550mm the machine is nicely balanced. Three lower rollers are fitted with one upper roller, all of which are sealed and lubricated for life.

The undercarriage also incorporates a new dozer blade design, which offers not only higher lifting height, but increased dozer digging depth, this can also give the operator more options when levelling up the machine on slopes or when landscaping at different angles, so a really nice feature.

At the business end, all the hydraulic rams on the boom and dipper feature cylinder guards to protect the chrome rods from any accidental damage and in addition to that cylinder safety valves are also fitted for the boom and dipper as standard. Also fitted as standard, are the breaker pipework with direct free-flow back to the tank, and 2-way high flow auxiliary lines are fitted for a myriad of hydraulic attachments settings which can be adjusted via the in-cab display monitor.

As is often customary with Doosan machines, this model was fitted with a fully automatic hydraulic quick coupler from Geith. An LED working light is housed in the middle of the boom well protected from any damage from trees and other obstacles.

Fitted with a standard 2090mm mono boom and the 1300mm longer dipper arm option the DX27Z-7 can achieve a maximum reach at ground level of 4720mm, a maximum digging depth of 2845mm and a maximum dump height of 3065mm. Arm tearout force in this configuration is 12.7kN (1300kgs) while bucket breakout force is rated at 21.8kN (2220kgs).

And so, to the cab, the first thing that struck me as I approached the machine was the full glass door, which extends from the roof to the cab floor, it’s an impressive feature for sure, and once ensconced inside the cab, offers outstanding visibility to that side of the machine with the door closed, I also like the integrated side-step feature with its built-in anti-slip design, ideal for those muddy boot winter mornings!

In addition, if you are one of those operators who likes to run the machine with the door open, in its retained position, the door remains safely tucked away inside the turning circle of the upper-structure to prevent any damage to the frame and ultimately what could be a costly piece of glass.   

The cab interior is clean cut and uncluttered and has a look of solid build quality to it. The floor features a familiar layout, with a foot rest to the left and a rocker style foot pedal on the right-hand side for adjusting the off-set boom feature. Strong looking T-Bar style track levers are provided with integrated foot pedals made of a strong composite material, which can be folded up to further increase floor space if desired.

The Grammer seat on this example was a heated mechanical suspension style, but customers can specify a heated air suspension variant, an option especially popular with owner operators. The joystick consoles can also be adjusted independently of the seat to suit individual operator’s preferences.

Most of the controls are located on the right-hand side console and are extremely simplistic and workmanlike. From the rear forward, a combination storage compartment is available for either a cup or a mobile device, a 12v power point is also provided in this location, as is a USB port.

A bank of 10 push-button controls is provided, 7 of them operational with 3 spares, for selecting the auto-idle function, windscreen wipers and wash, lights and weight overload alarm to mention a few.

As mentioned previously this machine was fitted with full air-conditioning and the controls for the fan and temperature were situated just behind the ignition key switch. The throttle control is a traditional electric dial situation just behind the all-new dozer blade control lever.

The new dozer lever has a nice joystick feel to it and fits nicely in the palm of the hand, this multi-functional lever can be used not only to adjust the tracking speed but also a low or high speed for the blade hydraulics too, in addition to these selection methods, the machine is fitted with an auto-shift travel valve which adjusts travel speed to suit the terrain the machine is encountering. Travel speed ranges from 2.4km/h in tortoise to a maximum 4.2km/h in hare mode.

No less than four fully adjustable air vents provide a good supply of cold or hot air around the cabin thanks to the enhanced heating/HVAC system, but for those who prefer the fresh air, both offside windows slide open, the front screen can be raised in the traditional manner and stored in the roof, while the lower portion of the front screen can also be removed and stored within the cabin.

The 5.7-inch touch screen monitor provides the operator with a whole host of information on the machine’s status, fluid temperatures, fuel level, and other critical feedback, in addition as previously mentioned the operator can select and adjust oil flows for specific attachments all from the seat of the cab. The DX27Z-7 can deliver a substantial oil flow of 58 l/min.

The DX27Z-7 is now the smallest machine in the Doosan hydraulic excavator range to benefit from the standard fitment of the manufacturers latest version 3.0 DoosanCONNECT system, offering end users a telematic management system that collects data from sensors located on the machine.

We put the machine to the test on a variety of jobs around this property. Sat in the seat the cab had a spacious feel, its much wider than on the previous model, and I must say, the visibility all round was super impressive, the rear window is rather small due to the space below it being used to store the air-conditioning package, but it's sufficient enough and to be honest, who actually looks directly out of the back window anyway. For those concerned about visibility to the rear, a rear-view camera kit can be provided on request, but in my eyes that would be a bit overkill and not really needed.

I found the seat to be super comfortable with plenty of adjustment to suit all shapes and sizes of operator. A flick of the key and the little Doosan engine sprang to life, with just a gentle thrum of engine noise, even at full chat, it is only rated at 78 dB(A) in the cab and 97dB(A) externally. Lowering the hydraulic isolation lever, and a quick tug on the right-hand joystick to raise the boom and we were away.

To get a feel for the machine I set about pulling a service trench in the back garden of this residential property. As we have come to expect from Doosan machines and to some extent Korean machines in general, the levers were super light to the touch, so much so that it initially caught me out a few times until I settled into how the hydraulics reacted to my touch.

It didn’t take long to adjust to it, and I quickly discovered there is really not much at all to dislike about this machine, smooth in operation, and with a 9.3rpm slew speed it's pretty lively too, with plenty of power to spare. It's surprisingly well balanced too and even my attempts to unsettle it with a full bucketful over the side failed, as it remained rooted to the spot, thanks in part to the 60kg additional counterweight fitted on this unit.  

Anthony demonstrated the machine’s ability to work in close proximity to buildings. The boom swing/offset angle is impressive, and by locating the boom off-set hydraulic cylinder on the left-hand side of the machine, enables the operator to work in very close proximity to walls and other obstacles on the right-hand side, without any protrusions that we sometimes see on other brands.

Over the years the Doosan DX27Z has developed a loyal following, and I have spoken to many customers over the years who have always given high praise for their performance and reliability, and from what I witnessed from this pre-production model, that reputation is only set to continue with the Dash-7 range.