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Driving John Deere’s S690 combine

Profi’s exclusive impression of the John Deere S690 combine. Profi says Deere is back with combine big boys


Editor’s note: “Profi” magazine is based in Europe and the machine referred to in this article is a European verion. Some of the features mentioned differ from those offered on a North American S690. However, the Profi article will give you a good indication of the machine’s overall ability and features.

For more information on Profi magazine, visit www.profi.com.

ohn Deere is placing all its high-output harvesting eggs in one basket and moving away from hybrid rotary technology on the new trio of S Series models, which cost more than $100 million to develop. We grab the opportunity to gain an initial impression of the S690.

Here in the U.K. and Ireland, John Deere’s best-selling combine range is the T Series. Not surprising, perhaps, as the (straw) walker market still accounts for a slightly larger slice of the region’s harvester sales pie. Content? Not a chance. The green U.S. giant wants more business in the top-end hybrid/rotary sector, and, while it has marketed the “C” and “S” machines for a number of years, neither have been rolling out in big numbers — well, not in our heavy-straw crops.

So Deere has headed back to the drawing board and looked at which system could offer the most potential. The result is a new four-model, (five in North America) single-rotor range. Why single-rotor and not hybrid? Deere says that, having gained experience with both systems, it has concluded the single-rotor set up is able to handle a much wider range of crops, so several years ago challenged its designers to make the configuration straw friendly, too. Prototype machines have been trialled for the past three seasons including testing in the U.K.

The S660

The baby of the new range is the S660, which in many ways is very similar to the current “S” machine, although it will not be offered in the U.K. and Ireland. On this side of the Channel the range starts with the S670, which comes with a 9.0-litre motor rated at 378 hp and a 34 hp power boost for unloading. The S680 and S690 both benefit from a 13.5-litre engine; in the two machines this motor is rated at 480 hp and 551 hp respectively with a 50 hp power boost. All of these engines are Stage IIIB-compliant (IT4), courtesy of their diesel oxidation catalyst and particulate filter, and they also have twin turbos.

Another common theme is the new, beefed-up elevator housing, while more powerful lift rams enable the machines to handle headers weighing up to 5.1 tonnes. This allows the combines to comfortably cope with 16- and 18-row maize (corn) headers, which weigh in at five tonnes and are becoming increasingly popular with North American operators. Our prototype S690 was carrying the 635R cutterbar — working width of 10.7 m (35ft) — and had no problems munching through the test’s short-stemmed wheat crop; full production 2012 machines will also have the option of the Zürn PremiumFlow 635PF header. The five-speed transmission, which is claimed to transfer up to 248 hp, has been retained for driving the elevator and header.

Shuffling back into the guts of the machine, we find JD’s familiar feed drum. This helps to present the crop in a uniform layer to the new Variable Stream Rotor. Though the rotor’s length and diameter haven’t changed, the front of the cone — this comprises the intake auger and threshing area — is now larger and has a longer taper. The new rotor has also been given a variable crop flow system, which allows the operator to select one of two settings for the top cover guide rails in the threshing area. The Deere theory behind these changes is to actively control the crop flow through the rotor so that the time the material spends inside the rotor is sufficient for the separation area to do its stuff. Setting the guide rails in their advanced position reduces the time the crop spends in the rotor by about 20 per cent over the standard setting, which means the combine can effectively increase its output by a similar margin.

Also, the less time the crop takes to pass through, the less the straw is bashed, decreasing the amount of short straw build-up on the sieves. This, together with other tweaks such as a taper at the end of the rotor and an overshot beater, means a decent swath is left behind when not chopping. That was our experience.

Our prototype S690 was equipped with JD’s Premium straw chopper — standard on the S670, S680 and S690 in the U.K. and Ireland. This unit sports 100 knives working against 57 fixed blades and receives the straw via an extra guide drum. Switching from chopping to swathing is all done by pressing a button in the cab, which shifts the chop to drop door. A mechanical gearbox reduces the chopper speed in rape (canola) from 3,600 r.p.m. to 1,800 r.p.m.

The Premium spreader also has electrically adjustable spreading vanes. The PowerCast spreader — standard on U.K./Irish S690s — allows the operator to alter the speed of each spreading disc independently and is able to throw material out to the 10.7 metre maximum working width of the current header. When the combine is swathing, material leaving the sieves passes through the chopper and is spread to the full working width. A plate moves automatically to ensure no chaff is found under the swath, and it is also possible to spread the chaff when swathing.

Threshing

Back to the threshing department, there have been changes here, too. On the S680 and S690, returns are no longer directed back to the separation area; instead a 40 cm diameter, 23 cm wide threshing drum is used to spread the grains across the sieves. A lever sets the clearance between the returns drum and concave anywhere from six mm for cereals to 70 mm for rape and maize. John Deere reckons that this design change — not returning grains to the separator — means operators will be able to run with the main concave wider to increase daily output. The S690 model has a 14,100-litre capacity grain tank, which opens hydraulically. The augers are driven by a new gearbox and stronger chain drive to improve the unloading rate — a claimed 135 litres/sec. With a full tank of grain onboard, a 10.7 m header up front and the 1,250-litre fuel tank brimmed, an S690 can easily weigh 30 tonnes, so the machine needs to put plenty of rubber on the floor if it is to prevent serious soil compaction. Tire choice extends to 680/85 R32 to provide a relatively tight on-road width of 3.5 m, or there are several 800 mm wide tire options.

Alternatively, John Deere is now offering a track system (only in Europe) that results in an overall width of 3.49 m; for now at least it will not be possible to fit these tracks to existing wheeled combines due to alterations to the axles and chassis. Each track is able to put a 0.66 m wide and 1.79 m length of rubber down on the ground, and the five idler rollers have a hydropneumatic suspension system, helping to ensure as much rubber as possible is in contact with undulating soil. Due to side loadings etc., HillMaster models will only be offered with tires. Track models also have an on-tarmac top speed of 30 km/hr., and, for extra sticky situations, there’s a rear-wheel-drive option priced at £14,100 ($22,760).

In the cab

Deere S-series combine operators sit in the upmarket Premium cab, which is said to be 30 per cent larger than the version used on its predecessor for the past 18 years.

As well as providing generally more space, there is plenty of leg room even for the tallest operators. The steering wheel can be set in three different positions, and the air-suspended seat has an adjustable armrest.

Noise insulation seems effective, as does the climate control. In addition, there’s a full fridge with separate controls — this unit will also be fitted to 2012 T-series combines — and there are 120 litres of storage space. Contrast that figure with the 45 litres in the lesser spec. Deluxe cab, which will be on W- series combines for next season.

There is the option of a Bluetooth radio — phonebook-compatible with separate buttons on the multi-function armrest — and the CD radio has a pair of speakers and a sub-woofer for kicking out the tunes.

Another substantial improvement has been made to visibility. Slim corner posts make it easier to see more of the header, while higher side windows give a pretty good view of the unloading auger. Only visibility glitch with our machine was the large 10-inch GreenStar 2630 display, which is mounted in the top right corner; on production machines, the 2630 is an alternative to the smaller seven-inch armrest-mounted GreenStar 3 terminal and is needed if operating yield mapping/documentation. If you only want to run AutoTrac automatic steering or Deere’s HarvestSmart control system, these can be used through GreenStar 3.

The multi-function armrest layout is similar to that of the 7R and 8R tractors, and the familiar and user-friendly joystick continues to tick most boxes. The right-hand cab pillar display is still in residence and shows the current header position, ground speed and crop losses.

Summary: The new S-series range looks capable of placing John Deere firmly back in the big combine league. It has plenty of power, an uprated threshing system, a chopper capable of spreading to the full working width (with a bit more in reserve), a rubber track option and a spacious cab for the operator.

The newcomers aren’t short on tech, either: the JDLink telemetry system will be fitted as standard to all 2012 combines. Deere also reckons to have the single-rotor job sussed when it comes to maintaining good straw quality. What remains unknown, though, is whether potential owners will be convinced by the maker’s claims that its updated rotary design is now better at coping with green straw. †

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