Market Report: Compact Plant : Mighty Mini ***** *****ward believes that JCB's Mini CX miniature backhoe loader represents a sensible alternative to a mini excavator for the average jobbing operator. Until now, most compact backhoe loader combinations sold into the utility market have been derived from Japanese compact tractors, with an agricultural loader and a locally produced backhoe. This is because 1800 backhoes are not widely available in Japan, which is strictly a 3600 excavator market. These machines have been designed for agriculture and landscaping, giving the reach and digging depth necessary for jobs like ditch cleaning and, as a result, are lightweight and not really suitable for heavy-duty construction use or serious excavation. JCB’s Mini CX is a sensible alternative to a mini excavator, with a ruggedly constructed centre-mount backhoe and the additional benefit of a front end loader with an optional 4-in-1 multi-purpose bucket. The futuristic styling conceals a fully integrated backhoe loader in miniature. Available only with a ROPS/FOPS canopy, the machine is easy to mount from either side. Sensibly large, open, cast aluminium scraper steps are set in a plastic moulding, which also serves as a fender for the rear wheels. Commanding view From the adjustable seat you get a commanding view over the steeply sloping bonnet to the back of the front bucket. Instruments are restricted to a display of warning lights as used on JCB’s Micro excavator and, in fact, as you walk around the machine you can see good use being made of many existing JCB components, particularly on the backhoe. The three-cylinder diesel engine just drives the variable flow hydrostatic pump and a single gear pump to power the loader, backhoe and steering. The key switch is located on the offside fender alongside the throttle control. To start the engine, the parking brake must be applied. This is a sensible safety precaution, as hydrostatic transmissions have a habit of creeping when in neutral. Having set the engine speed and depressed a safety interlock pedal with your left foot, all direction and speed is controlled by forward and reverse pedals under the right foot. Hydrostatic transmissions provide both positive drive and braking, so there is only a requirement for the parking brake. In the case of the Mini CX, this is a cable-operated exposed disc on the front of the drive axle. Surprising amount of grip In spite of having only two-wheel drive, there is a surprising amount of grip from the wide based traction tyres, helped by being run a bit on the soft side and by the weight of the backhoe. The loader control to the right of the operator has an ISO layout, with the optional multi-purpose bucket clamshell operated through a press button switch on the control lever. The test machine lacked both a bucket level indicator and a clamshell opening indicator, but I soon got used to this. However, these omissions are to be rectified on future production units. The bucket cylinders are directly attached to the bucket and, as a result, ground level rollback and discharge angles are a bit of a compromise. The rollback is good but the full height dump angle is not quite enough to get a clean discharge; fortunately, bottom dumping the multi-purpose bucket overcomes the problem. Untrained operators should be aware that the machine does not feature parallel lift and there is a risk of spoil being discharged on to the bonnet. This is a mistake you only make once. As a loader, the Mini CX is good. The bucket fills easily and performs all the multi-purpose functions with adequate traction from the two-wheel drive axle, which is equipped as standard with a limited slip differential. However, as with many hydrostatic transmissions, the operator needs to know to lift off the travel pedal and reduce the speed as the load increases to avoid stalling the engine. Unlike most tractor-based backhoe loaders, on the Mini CX you can change from loader to backhoe control without leaving the seat. By pulling a short lever on the near side of the seat you can fairly easily rotate to face the backhoe controls. Either JCB Plus controls or an ISO layout can be specified. I would guess that most will opt for the latter, as the machine is most likely to be used as an alternative to a tracked mini excavator. Interchangeable attachments The centre-mount backhoe uses many components from JCB's Micro and 8015, so buckets and attachments such as an hydraulic breaker or earth drill are interchangeable. The auxiliary hydraulic service is an optional extra. The widely spaced outrigger stabilisers provide good level-up and exceptional stability, even over the side. The backhoe performs well with plenty of ‘grunt. The unit has a single pump and the engine needs to run close to maximum speed. Professional mini excavator operators might find it a little slow, but overall the machine is a seriously good unit that will provide more than enough performance for the average jobbing operator. Do not be put off by the fact that the backhoe is centre-mounted: for rare occasions when it is necessary to dig alongside an obstruction, the machine can be placed at 45? and only the outer stabiliser lowered to perform the task. The Mini CX is an all-hydraulic machine with both the transmission and loader/backhoe hydraulic systems fully sealed. With no clutch, gears or brakes to go wrong, it is easily maintained. Service intervals revolve around an engine oil and filter change at 250 hours, although it is necessary to grease the main pivot points at approximately 10-hour intervals. EHN’s tests were designed to show what the CX is capable of, rather than out-and-out performance. The ground comprised damp sand and gravel that had been previously dug but then lightly compacted. In terms of resistance to digging it would be typical of most conditions. I initially dug a 450mm trench 1000mm deep for 20 minutes, which was then backfilled using the loader. The fuel consumption was recorded on both tests. The hourly trenching output equates to the chart below: Output Linear | 26.10 | m/hour | Output | 11.75 | bank m3/hour | Output | 13.39 | loose m3/hour | Output | 22.64 | tonnes/hour | Fuel | 3.30 | litres/hour | Fuel | 0.15 | litres/m3 | Fuel | 6.86 | m3/litre |
The backfill and levelling test on the same trench took 6 minutes and 53 seconds, with an hourly output of: Output Linear | 75.84 | m/hour | Output | 34.13 | bank m3/hour | Output | 38.90 | loose m3/hour | Output | 65.79 | tonnes/hour | Fuel | 4.36 | litres/hour | Fuel | 0.11 | litres/m3 | Fuel | 8.93 | m3/litre |
Finally, I loaded a 2 tonne site dumper from a stockpile with six passes in 2 minutes and 7 seconds using the loader. Fuel consumption was not recorded on this test but would be approximately 3.75 litres/hour from the two previous tests. The hourly loading output figures would be: Output | 32.32 | loose m3/hour | Output | 55.62 | tonnes/hour |
Compared to most tractor-based compact backhoe loaders, the Mini CX lacks four-wheel drive, as well as the added flexibility of a three-point linkage and power take-off to drive rotary cultivators and other attachments. But as a purpose-built backhoe loader it does the business, It is ruggedly constructed, simple to operate and gives adequate performance even with two-wheel drive. It will rarely work in a production environment, but is a serious alternative to the mini excavator for those who require the facility of a loader and the mobility of a wheeled machine. 01889 590312 www.jcb.com |