Last year land-based assessor and engineer Andrew Griffiths tested the Bobcat E09 micro-excavator and was "bowled over" by the ability of the tiny machine. But what will he make of this?
The E35 is delivered to site on time by AMS Bobcat of Scunthorpe. It's on the back of a lorry. This is a heavy machine and the weight of three buckets has increased it further - something to remember when you think about transporting this unit.
The interior of the cab is smart. Griffiths jumps in and throws open the front window, sliding it back into the overhead storage space. "It's a small cab - almost claustrophobic - but the visibility is good," he comments. Griffiths is more used to 14-tonne machines but it doesn't take him long to acclimatise to the smaller size that naturally comes with a zero-tail-swing machine. "You know your back end isn't going to hit anything as you are slewing and you can work close to obstacles," he says.
Three or four old leylandii stumps need removing at the edge of the car park. We've looked at the site plans and discovered there used to be a building just feet away; there may still be some foundations. But a scan with the Digicat suggests there are no utilities in the way. Griffiths carefully tracks the E35 into position and gives one of the stumps a nudge. It rocks a little so he begins to excavate around it.
"Amazing power," says Griffiths. "In fact, the machine almost has more power than its weight can handle - but it is better that way than not enough. You have to keep the revs down. If the revs are up the machine tends to be jumpy - it reacts too quickly."
Keeping the revs down helps keep the noise low too, although noise is not an issue with the E35. It purrs.
Bobcat tells us the load-sense piston pump and the closed centre valve provide exceptionally fine metering of hydraulic flow for smooth, precise control of machine functions, while reducing hydraulic noise. The boom and dipper arm cylinders are cushioned to provide a smooth, end of stroke operation. The boom on the E35 consists of a four-plate box design with internal gussets. This reduces the weight while providing strength and increased lift capacity.
Griffiths needs little time to familiarise himself with the machine's controls. The travel pedals are made of cast aluminium and, when not in use, can be folded forward to provide more leg room. The travel levers are positioned adjacent to each other and can be used one-handed, leaving the other hand free to adjust the blade. Operation of the blade is now on the joystick, but at first Griffiths finds it difficult to feather - it's either up or it's down. The abruptness of the slewing movements also comes as a surprise until you get used to it. "It takes a little practice to get very gentle with it - I'm finding it a bit like a Caterpillar in that respect," he says.
The stumps prove more stubborn than they first appeared. Griffiths has to swap the buckets several times. "Quick hitch would be nice," he says, having trouble with what appears to be a slight twist to the headstock. After two bucket changes, we find we have lost one of the securing pins. "They are too long and there is no guarding. I think they are getting caught in the muck as I am digging," suggests Griffiths.
He also has to make a lot of changes in position. The pit around the stumps gets wider - and deeper. An important new feature on the E35 is the auto-shift travel motor, which allows an automatic transition from the low to the high speed range or vice versa. We couldn't find the control at first - it's a rocker switch on the right-hand dash. If the auto-shift is not engaged, you can use the switch located on the blade control lever to select the travel speed required.
Griffiths is impressed with the tracking power. "A lot of the small excavators I have used in the past have been very poor on tracking power. But this one is good," he states. And just to prove a point, he drops into a hole and makes the machine pull itself out.
We also find that, perhaps because of the zero tail-swing and lack of projecting counterbalance, the machine does not tend to pitch when tracking. "If feels lovely and stable in that respect," says Griffiths.
Another useful feature is the auto-idle. Engaged at the operator's discretion, the auto-idle facility automatically causes the engine to drop to idle if the excavator functions are not used for a period of about four seconds - thus saving fuel, lowering noise and reducing emissions. The engine automatically returns to the pre-set throttle position when the operator moves the joystick or a travel function.
Griffiths uses the E35 to back-fill the hole and grade out the earth. He uses the side-shift facility to offset the boom. "That's handy," he says. "It means when I am on solid ground and don't want to track and move, I just put it on side shift - very useful." The control for boom offset is thumb-operated and is positioned on the left joystick, in contrast to the pedal control used on many excavators in the three-tonne class.
Maintenance of the E35 looks remarkably straightforward. The tailgate swings wide open to expose the dipstick, header tank, oil and air filters, while a side-gate gives access for changing hydraulic filters. The design of the hydraulic components and routing of the hydraulic hoses and hydraulic connections should mean a reduced chance of leaks. Quicklock snap-to-connect fittings for connections to the valve block ports reduce stress on the fittings as they exit the valve, further reducing the risk of leaks. Bobcat tells us that, compared to the classical 90 degs fittings, the Quicklock fittings generate less heat and thus lower the cooling requirements of the machine.
The air conditioning condenser and hydraulic cooler can be separated for cleaning purposes, without the need for tools. The starter, alternator and compressor can be taken out by removing the counterweight. Auto-tension belts help to reduce maintenance. "The tailgate and side-gate are made of a strong plastic material so they won't rust if they get scratched," notes Griffiths.
We take a look underneath. The undercarriage features sealed, maintenance-free track rollers, a top roller and wide sprockets. The open design and sloped surfaces of the X-frame prevent the build-up of mud and debris. "It's very neat and tidy, nothing to snag, and the track motors are well protected. It's a good, solid construction," says Griffiths.
Summing up, Griffiths thinks back to the E09. "That was remarkable - what that machine would do for its size," he recalls. "This one is three-and-a-half times bigger and it won't go into the small spaces the E09 would access. But it's still a nice compact machine - stable and with loads of power. I like the improvements Bobcat has made."
Operating weight (with cab, rubber tracks and 61cm bucket) 3,493kg
Maxi digging depth 3.12m
Maxi reach at ground level 5.23m
Dump height 3.44m
Engine Liquid-cooled, three-cylinder Kubota diesel delivering 24.8kW at 2,650rpm
Track width 32cm
Travel speed 2.6km/h low range; 4.7km/h high range
Auxiliary hydraulic flow 63.9 litres/min
Length in travel position 4.83m
Height to top of cab 2.43m
Ground pressure with rubber tracks 28.8kPaw
Contact Bobcat on 0800 756 6813
The reviewer Andrew Griffiths, land-based assessor and engineer, College of West Anglia, Milton, Cambridge
Ground conditions Good