Hay & silage: Lely Hibiscus 725 CD Master rake
This month Brent Lilley takes a look at an innovative and heavy-duty rake from Lely which ticks all the boxes in terms of strength and agility.
A good rake tends to be the unsung hero of any forage operation. It's key to pulling together a large amount of forage, leaving a tidy (and hopefully uniform) row that can have a massive influence on the output of the machine following it. The importance of this can sometimes go unnoticed — until there's a problem. Anything from a poorly-formed row or, heaven forbid, a breakdown when you're under pressure can really affect the output. There's nothing like picking up single mower swaths after such an incident to remind you of the importance of your rake.
These thoughts sat in the back of my mind when looking over the Lely Hibiscus 725 Master rake back in September, just as we were beginning what was set to be a great silage season with excellent early growth.
The rake was purchased from Piako Tractors in Morrinsville earlier in the year to replace an older 680 Claas Liner. It is being used on some challenging terrain, particularly around the eastern Coromandel Peninsular, so agility and strength were key requirements for the operator.
Strength it certainly has and according to the guys at Piako, most people who see it for the first time describe it as being 'built like a brick… err… outhouse'. Everything about the main frame of the rake is incredibly well-built, starting with the U-shaped headstock at the front mounted to the lower link arms of the tractor, with plenty of clearance for the PTO shaft. Like most other rakes, the headstock joins the main beam of the rake with a heavy-duty greasable pivot point that allows the rake to trail behind the tractor. A robust box section beam runs the length of the rake, onto which the rotor arms and wheel assembly are then mounted.
The main difference between this rake and virtually every other rake I've come across is the rotor arms that join the rotors on either side. The Lely features robust box-section A-frame shaped arms that mount to the main beam in two places, nearly two metres apart, to give unrivalled strength and stability to the rotors. The lift for the rotors is taken care of by a double-acting hydraulic ram on either side, which are also required for the width adjustment of the rake.
The heavy-duty nature of the rake is continued through to the wheels at the rear of the machine, with hefty cross beams and more box section steel to support the stub axles for the wheels at the back. These wheels are self-steering via a connecting rod from the headstock at the front to insure the rake will follow in the tracks of the tractor front.
Rotors and tines
The rotors are fundamentally the most important part of any rake and because of this, quality and reliability of the rotors is key. Lely incorporates a modular rotor head on all rakes that is completely enclosed and sealed. In the factory the cam track on this rake is greased with special-purpose grease intended to last its lifetime and reduce on-going maintenance requirements. Drive to the rotor heads comes from a three-way oil-filled gearbox in the centre of the rake via a standard driveshaft with overload protection. Each rotor has 11 tine arm holders extending from the rotor head that the steel tube tine arms slide into. This helps limit any damage if an obstacle is struck. Four tine arms on each rotor can be removed to give a transport height of 3.4 metres, with storage for the arms at the back of the chassis.
Under each rotor is a carriage with four wheels on pivoting bogies to support the weight and assist the rotor in following the contours of the ground. One downside of this rake is it only features a side-to-side pivot between the rotor arm and the rotor, unlike many other makes and models that feature a 3D ground-following cardanic linkage allowing the rotor to pivot in all directions.
As with all Lely rakes, this model features its Ro-Tine which, unlike many other straight rake tines, has a curved shape to it. This, combined with a mounting position on the tine arm, means the tip on the tine slightly trails behind the rotor arm to pick up material and move it with much less drag and soil contamination. Tines are mounted around the tine arm like many other rakes, which is simple and works well, although it can be tedious when you need to replace the inside tine by having to remove all the others.
Controls and working adjustments
Controls are pretty simple with one double-acting set of spool valves required on the tractor to raise and lower the rake. An optional extra for this rake is an individual rotor lift kit.This requires another set of spool valves, but it allows each rotor to be lifted individually, great for raking triangles or the last run in the paddock and around obstacles.
There are three working adjustments that can be made on the Lely. Firstly, like almost all rakes, the height of the tines from the ground can be adjusted via a crank handle on each rotor that allows the carriage under the rotor to be raised or lowered.
The second working adjustment is the width of the rake. This can be set in two positions — 6.95m or 7.25m. To allow for this there are plates where the rotor arms meet the main frame. These plates slide downwards and outwards, moving the hinge point away from the main frame and making the rake wider when working, without affecting the overall folded transport height of the rake – simple in theory, not so simple in practice. With five bolts of two different sizes in each of the four plates, there are 20 bolts that need to be loosened or removed and two pins and a linkage on the swath curtain to change — this setting probably isn't going to get altered too many times.
I've saved the best adjustment, in my opinion, till last — the adjustable cam track, located under the rotors with 13 positions that adjust the rotation of the cam track, giving you control over the position of the tines when they lift from the ground to drop the material. With the right operator using the rake, who isn't afraid to hop out of the cab a couple of times, the tines can be adjusted to leave a square uniform row in most crops and conditions to improve the output of the machinery following the rake.
Lely has once again stepped up to the mark with this robust and innovative rake. The adjustable cam track A-frame shaped rotor arms and their curve-shaped Ro-tines are a great example of innovation at its best. For me, the positives definitely outweigh the negatives, which include a lack of 3D ground following and the difficulties involved with adjusting the working width. For those of you not convinced this is the machine for you, the new Lely Hibiscus 745 Vario model, set to follow the 725, may be just the ticket.
Among other things, the new 745 features a hydraulically-adjustable working width and 3D ground following, which I'll hopefully get to test out in the not-too-distant future.
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