A second-hand diet feeder could provide a cost-effective boost to feeding logistics. Geoff Ashcroft sought some buying advice from Kverneland’s diet feeder specialist.
Largely robust and mechanically straightforward, few machines are relied upon like a diet feeder, although you will need to look carefully to find a good used example.
While we used a four-year-old Kverneland Siloking Duo as our example, many of the things to look for apply to most vertical auger diet feeders.
This Duo uses two vertical augers to mix rations inside its 26cu.m tub. It is equipped with a host of extras to assist with feeding, including twin-lift front cross conveyor, hydraulic rear door and Pro II on-board weighing system.
Kverneland’s Phil Vickery says: “There is no hour meter or load counter, which means buying on condition is everything. Expect a machine of this size, age and condition to fetch about £15,000-£17,000.”
Climb the ladder and take a look into the tub. If the machine has been recently worked, it will reveal much about its mixing and emptying capability.
Ideally, the augers should leave a clean sweep and leave little material in the tub.
If material is present after emptying, then this could point to signs of blade, paddle, or even auger wear.
Twin axle mixers often come with a following axle which needs to be locked hydraulically when reversing. It also makes a larger machine as manoeuvrable as a small one, says Mr Vickery - a plus point when weighing up available yard space.
Hydraulic brakes and parabolic leaf springs are robust, but need to be checked. Look out for broken leaf springs and excessive wear of running gear components.
Tyre and brake wear also need careful evaluation if road work has been done, or needs to be carried out.
While under the machine, inspect the main gearboxes for signs of oil leaks and check the driveshafts, as they require greasing.
Knives do wear, but with only eight per auger on this machine, they are relatively inexpensive to replace compared to a horizontal machine’s multiple smaller blades, says Mr Vickery.
Adjustable counter knives on the tub body should also be in place, which help the chopping and mixing action.
Many makes feature useful optional extras which are worth looking out for, such as a straw ring around the lip of the tub (pictured, below), which helps to retain bales during mixing.
Some models can also be fitted with optional tub magnets, which are useful to catch and retain any metallic materials which may have found their way into silage.
On this machine, knives at the top of the augers are carried on strengthening plates - it prevents them from bending when bales are dropped into the tub.
While auger wear rate is quite low in general, a Hardox repair kit is available for most machines.
A dummy paddle, which must be in place, is often fitted at the bottom of the auger opposite the main flight, which provides balance and helps to keep material on the move. It also helps with emptying of the tub.
To check the weighing system and its operation, power up the box. It will also confirm the four weigh cells under the tub are functioning.
The in-cab controller (pictured, right) also needs to be thoroughly gone through.
Depending on machine specification and options fitted, some buttons will not be used.
When safe to do so, check machine operation and run through all the available controls to ensure they work as intended.
The optional twin lift cross conveyor gets a hydraulic motor at each end.
“Depending on which way the belt is unloading, you are always pulling a tight belt,” says Mr Vickery. Inspect the belt for tears, cracks or missing ribs and signs of misalignment.”
This conveyor is missing both its wind guards, which should be in place to deflect forage into a trough.
An optional hydraulic rear door is powered directly off the tractor’s spool, and is a good insurance policy to have if the conveyor ever fails.
“At least you can continue feeding - even if it is only to discharge grub into a loader bucket,” says Mr Vickery.
Each auger gearbox on the Duo comes with its own remote-mounted oil reservoir, located on the side of the tub.
On any machine, check oil levels and look for signs of contamination in the oil. Contamination could be a sign of gearbox problems, which could prove costly down the line.
Pto guards should be intact and secured - pulling the main shaft apart will reveal if it has ever been greased and may give an indication of general machine maintenance.
Check that fail safe protection devices are in place and working, such as shearbolt or slip clutch protection, often located ahead of the main gearbox.
The lights and rear bumper on this machine were largely free of impact damage, which suggests its owner has been careful when backing into sheds and feed passages.
“The level of damage sustained at the rear of a diet feeder is often a good indication of how these machines are looked after,” says Mr Vickery.