4 September 1998

JDs CTS makes it a smooth ride for the operator

John Deere has still to launch

its CTS combine officially in

the UK, despite there being

a number of machines on farm.

Ian Marshall found out how

the evaluation was going

SHAKE rattle and roll – movements many combine operators will be familiar with as they engage the threshing mechanism on a straw walker machine.

But they are alien sensations to drivers of rotary models, including John Deeres representative in this sector, its Maximizer CTS, short for Cylinder Tine Separator.

Originally developed in the States as a rice harvester, the Maximizer is powered by an 8-litre engine putting out 260hp. Primary separation follows established design convention, with the cut crop being taken to a 1.4m wide, 60cm diameter (4.7ft x 24in) drum.

There is then a divergence from accepted principles. On leaving the drum, straw is split into two flows by a divider roller before entering two longitudinal, contra rotating, rotary separators. Each is 50cm (20in) in diameter and is gearbox driven at either 700rpm or 500rpm.

Grain separation is by a series of tines along the length of each rotor. These comb kernels from the crop mat, which is pulled through the separator housing in a loose ribbon and then out through the rear.

The CTS had its first experience of UK crop in 1996 and is still undergoing evaluation work here.

One of the latest build Maximizers to come into the UK is being used by Robert Grindal in Lincolnshire, where farmers weekly caught up with it.

"Although the combine needs to be fine-tuned in terms of settings for different crops, the basic principle is sound and it is the way to go," he says on the decision to invest in a yet to be totally proven harvesting principle.

"A powered system has far better separation properties than putting the crop across straw walkers. And without the straw walker drives there are far fewer moving parts, so the combine is going to last a lot longer."

Farming in partnership with his father, Joe, at Hall Farm, Lobthorpe, the Grindals have 505ha (1250 acres) of autumn sown wheat, barley oilseed rape and linseed.

Their CTS is fitted with a 7m (25ft) table and having completed the barley and rape and into second wheats, Mr Grindal has not changed his opinion of the machine. Although, he says, the combine definitely needs more engine power and it is still a learning curve getting the correct combinations of settings.

The main problems have been wind volume and getting the right area of sieve. "We started the season with the 700rpm separator rotor, drive gearbox which was smashing the straw and contributing to overloading the sieves," says Mr Grindal.

"Reducing the rotor speed by fitting the 500rpm drive gearbox certainly made a difference. And, through trial and error, we have alleviated some of the fan and sieve setting problems.

"Initially we were lifting both the grain and the chaff together. By gradually closing down the sieves and reducing the wind, we are now at a point where the grain is getting to the sieves. But it is a fine balance to get the chaff to rise and the grain to fall."

To get a more precise idea of the effect their setting combinations were having before moving into the first wheats, the chaff spreader was taken off to get a better idea of how much grain was going over the back of the combine.

"The higher yielding crops are the acid test," says Mr Grindal. "But they have shown that we are getting the wind/sieve setting combination right; 35t/hour is going through the combine and we are losing a tested 0.5%.

"But we have found that to maintain the output you have to change the setting through the day to suit the conditions. The wind setting is higher in the morning and afternoon than the evening, as the straw is more brittle."

Accurate settings might be difficult to achieve but when it comes to driving the CTS, the combine definitely falls into the operator-friendly category.

The cab is extremely comfortable and even with the engine at full power, the lack of straw walker drive means a quiet, rock-steady working environments.

As with any modern cab, full adjustment on the seat and steering column mean a comfortable driving position. Visibility across the table is generally good, you soon get used to the width.

Controls, either toggle or rocker switches, are well laid out and reached on the right-hand console. They are typically American, big and chunky, which lets you get a firm grip of them. On the move, the combination of the hydrostatic drive and the header controls on the armrest-mounted joystick enables the operator to react immediately to changes in crop conditions.

Surprisingly though, there is no return to work function on the joystick for the table or reel, nor is there a header dead stop.

When in work, the grain tanks 9000 litres means you can get a good run in the crop. But, in addition to the tank full signal, it could do with half and three-quarter full indicators to give the operator a better idea of when to call the trailers up.

But a lack of these features does not impair the operation of the machine and they may well be incorporated in the CTS model which at last hits the market. &#42

MAXIMIZER CTS COMBINE

&#8226 Engine 8.1 litre, 6-cyl. Turbocharged and air-to-air aftercooled.

&#8226 Power Max at 2200rpm 260hp; 278hp at 2100rpm. 293hp with unloading power boost.

&#8226 Cylinder Rasp type, 1.4m wide x 66cm diameter.

&#8226 Cylinder speed 240-980rpm.

&#8226 Tine separator 46cm front/50cm rear section.

&#8226 Separator speed 700rpm, optional 500rpm.

&#8226 Total separating area 2sq m.

&#8226 Transmission 3-speed hydrostatic.

&#8226 Grain tank capacity 9000 litres.

&#8226 Unloading rate up to 70 litres/sec.

&#8226 Fuel tank 530 litres.

&#8226 Max height to loading auger 3.9m.

&#8226 Transport width 3.8m.

&#8226 Base weight less header 12,780kg.

Maximizer by name, but not yet by nature. "It will live up to its name when it has more engine horsepower and a larger sieve area, which will allow the tremendous potential of the straw rotors to be fully utilised," says Robert Grindal.

Quiet environment for the operator with visibilty said to be on the plus side.